To see the other types of publications on this topic, follow the link: Polyvinyl chloride.
Dissertations / Theses on the topic 'Polyvinyl chloride'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Polyvinyl chloride.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
El-Akesh, Esmail Omar. "Thermal decomposition of chlorinated polyvinyl chloride systems." Thesis, University of Salford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492419.
Full textAbstract:
The thermal decomposition of chlorinated polyvinyl chloride (CPVC) systems has been investigated using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and pyrolysis-gas chromatography mass spectroscopy (PyGC/MS) techniques. The influence on the thermal decomposition of CPVC of atmosphere, heating rate, stabiliser, lubricant, dioctyl phthalate (DOP), alkyl diaryl phosphate (Santiciser 2148) and triaryl phosphate (Refos 50) plasticisers and also the smoke-suppressing u-on(III) compound basic iron oxide (FeOOH) in these polymer systems has been studied.
2
Perry, Katherine Louise. "The diffusion of acetone into polyvinyl chloride." Thesis, University of Surrey, 1994. http://epubs.surrey.ac.uk/844641/.
Full textAbstract:
The diffusion of small molecules into glassy polymers is often observed to be of the anomalous Case II type. This thesis describes the first comprehensive study of acetone vapour penetrating into PVC. It has been shown that this diffusion process is of the Case II type. The initial stages of the diffusion process have been studied using ion beam nuclear reaction analysis (NRA) whilst long range diffusion has been studied using broadline nuclear magnetic resonance (NMR) imaging techniques. This is the first time that short and long term behaviour has been studied in the same system and has permitted a test of the Thomas and Windle theory covering both regimes. It is also the first time that broadline NMR imaging has been used to study Case II diffusion and this has permitted a study of the polymer as well as the penetrant. A new NMR technique has been developed for this. Characteristic parameters of the diffusion process have been determined. The velocity of the diffusion front advance is typically 0.042 mmhr-1 and the diffusion coefficient is 7 x10-11 cm2s-1 at room temperature. The effects of variation of exposure temperature and the activity of the vapour on the diffusion dynamics have been investigated. The NMR profiles have shown an unexpectedly long Fickian precursor extending into the inner glassy core of the samples. To complement the NMR imaging results, the NMR spin spin relaxation times of samples have been measured, and high resolution 13C NMR spectroscopy has been performed on the samples. Evidence has been found for continued disentanglement of the polymer chains long after mass equilibration of the region of the PVC swollen by acetone vapour. This disentanglement has been shown to be strongly dependent on the exposure temperature.
3
Gong, ShiYi 1970. "Hydrodechlorination of polyvinyl chloride in sub-critical water." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=98711.
Full textAbstract:
Polyvinyl Chloride (PVC), a plastic polymer composed of ∼43% hydrocarbon by weight and ~57% chlorine has become extensively used in our daily lives. However, the disposal of waste PVC plastics presents serious problems. The increased awareness of these problems requires the development of a reliable technique to dispose of these wastes in a safe and environmentally benign way that is devoid of the formation/release of organo-chlorine compounds. Chemical degradation of PVC is a technology that transforms PVC waste into completely new chemical products that don't contain chlorine. Sub-critical water (SCW) treatment is one of the most reliable technologies since SCW as a chemical reaction medium having adjustable physico-chemical properties. Hydrodechlorination (HDC), a reaction that replaces organically bound chlorine by hydrogen, can be accelerated by the presence of metal oxide catalysts (alumina supported palladium, Pd0/Al2O3) or raney nickel. When combined with SCW treatment, HDC offers a disposal process that is free from unwanted by-products. The rate of borohydride decomposition is accelerated by raney nickel. The HDC efficiency of virgin and formulated PVC in SCW under various reaction conditions of time and temperature was evaluated systematically. The time of reaction was varied from 1 to 4.5 hours and the temperature was varied from 150 to 280°C in the presence of palladium on alumina (Pd/Al2O3) or raney nickel. The efficiency of HDC varied from ~3% up to a completed dechlorination. Thus, organically bound chlorine in PVC in a water phase can be converted, virtually quantitatively, to chloride ion.Response surface methodology (RSM) was used for experimental design and data analysis. The computer output from the Design-Expert software was used to optimize a model for the dechlorination as a function of time and temperature. A subsequent analysis of variance associated with the fitted model indicated a good fit between observed and predicted HDC efficiencies.
4
Dib, Shelby A. "Stability of Phenylephrine Hydrochloride in Polyvinyl Chloride Bags." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1562926540976767.
Full text
5
Lee, David W. "Thermal degradation of polymer blends containing poly(vinyl chloride) /." Online version of thesis, 1987. http://hdl.handle.net/1850/10287.
Full text
6
Matuana-Malanda, Laurent. "Wood fiber/polyvinyl chloride composites and their microcellular foams." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0002/NQ27693.pdf.
Full text
7
Santamaria, Estibaliz. "The performance and mechanism of a novel stabiliser for PVC." Thesis, Manchester Metropolitan University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248378.
Full text
8
Elraghi, Somia. "Polyblending of rigid PVC with kraft lignin application to the building exterior facade /." Thesis, Connect to online version, 1993. http://0-wwwlib.umi.com.mercury.concordia.ca/cr/concordia/fullcit?pMM87260.
Full text
9
Do, Tuyet-Trinh. "Thermal degradation of polyvinyl chloride blends / by Tuyet-Trinh Do." Thesis, Queensland University of Technology, 2000.
Find full text
10
Erdoğdu, Cem Aykut Balköse Devrim. "The development of synergistic heat stabilizers for PVC from Zinc Borate-Zinc Phosphate/." [s.l.]: [s.n.], 2004. http://library.iyte.edu.tr/tezler/master/kimyamuh/T000509.pdf.
Full text
11
Stroyan, Jared James. "Processing and characterization of PVDF, PVDF-TrFE, and PVDF-TrFE-PZT composites." Online access for everyone, 2004. http://www.dissertations.wsu.edu/Thesis/Fall2004/j%5Fstroyan%5F121704.pdf.
Full text
12
Jiang, Yunhong. "Antimicrobial behaviour of Polyvinyl Chloride(PVC) films coated with ZnO nanoparticles." Thesis, University of Leeds, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.545697.
Full text
13
Lo, Chung Keung. "Voltammetric and spectroscopic studies of dye-immobilised poly(vinyl chloride) membranes." HKBU Institutional Repository, 2003. http://repository.hkbu.edu.hk/etd_ra/425.
Full text
14
Grant, J. "Ferrocene containing smoke suppressants and flame retardants for semi rigid polyvinyl chloride." Thesis, Northumbria University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317038.
Full text
15
Prystay, Marc C. (Marc Christopher). "Photothermal imaging of optical polymers, polymer metal interfaces and photodegradation of polyvinyl chloride." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41750.
Full textAbstract:
Photopyroelectric spectroscopy (PPES) is a relatively new nondestructive photothermal technique that uses a pyroelectric sensor placed in intimate contact with thin film samples to record the photogenerated thermal waves transmitted by the sample. In this thesis it is demonstrated that photopyroelectric spectroscopy is capable of recovering profiles of optical absorptivity in micron scale thick polymer laminates with submicron depth resolution. The pyroelectric method has also been used to characterize adhesion at polymer/metal interfaces from the photothermal impulse response using both the transmission and inverse detection geometries. The PPES technique can also map the distribution of polyene bands created during photodegradation of polyvinyl chloride. Results are obtained in the frequency and time domains using conventional lock-in detection, excitation with wideband time domain sweep waveforms and wideband homodyne techniques. The experimental photothermal results can be modeled using the linear properties of heat conduction to obtain quantitative values of the optical and thermal properties of the samples.
16
Conley, Mark Lewis. "Mechanistic investigations and optimizations of thermal stability in polyethylene and polyvinyl chloride blends." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53938.
Full textAbstract:
The thermal stability of two distinct blended polymer systems was examined. A model for polyethylene was used to investigate the vulnerability of polyethylene to premature crosslinking in industrial crosslinking conditions. Careful experiments were conducted to gather evidence of the interaction between a peroxide crosslinking agent and a specific antioxidant additive. Multiple lines of evidence were combined to propose a complete mechanism of interaction between the two species. The mechanism was further tested and a hypothesis was proposed for the reduction in premature crosslinking exhibited when the two species are present in polyethylene blends. A specific aspect of the proposed mechanism warranted further investigation on its own. The acid-catalyzed degradation of the peroxide initiator was thoroughly investigated.
The thermal degradation of polyvinyl chloride was also studied. Model compounds were reacted with carboxylates to determine the relative rates of stabilization at various polymer defect sites. These model studies were combined with weight loss and color change investigations of bulk polymer systems. The knowledge gained from the model and polymer studies allowed for the proposal and examination of two novel stabilizing salt systems. The efficacy of the new stabilizers is presented.
17
Vess, Lora Elizabeth. "The politics of PVC /." Connect to title online (Scholars' Bank) Connect to title online (ProQuest), 2007. http://hdl.handle.net/1794/6195.
Full textAbstract:
Thesis (Ph. D.)--University of Oregon, 2007.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 252-277). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.
18
Ramacieri, Patricia. "Microstructure and kinetics of thermal degradation of alkene copolymers of vinyl chloride." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72819.
Full text
19
Murray-Chiasson, Audrey. "Étude de la relâche des inclusions lors de la filtration de l'aluminium liquide /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2002. http://theses.uqac.ca.
Full text
20
Mao, Feng. "Permeation of hydrocarbons through polyvinyl chloride (PVC) and polyethylene (PE) pipes and pipe gaskets." [Ames, Iowa : Iowa State University], 2008.
Find full text
21
Flanagan, Leslie. "Environmental assessment of the re-use and recycling of unplasticised polyvinyl chloride window profiles." Thesis, University of Brighton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324398.
Full text
22
Johnson, Garrick. "The Effect of Fungal Growth on Potential Phthalate Ester Exposures from Plasticized Polyvinyl Chloride." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5048.
Full textAbstract:
This study examined the effects of the presence of fungal growth on the phthalate ester content of plasticized polyvinyl chloride (pPVC) used as the vapor barrier component of metal building insulation and the impact the fungal growth may have on the resulting exposure potential to the workers in the building. Individual pieces of the pPVC material exhibiting fungal growth and individual pieces of the pPVC material exhibiting no fungal growth were collected from the building being investigated. Twenty-five pieces each of the pPVC material exhibiting fungal growth and of the pPVC material exhibiting no fungal growth were weighed, reduced to small pieces, and extracted with dichloromethane. The extracts were analyzed using a gas chromatograph coupled with a mass spectrometer. The phthalate content of four phthalate esters identified in the pPVC: diethyl phthalate (DEP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), and di-(2-ethylhexyl) phthalate (DEHP), was quantified and the results extrapolated to concentration based on weight ([um]g/Kg) and area ([um]g/m2). A paired samples t test and independent samples t test was used to identify where significant differences occurred (α = 0.05) in the phthalate content between pieces. Using the mean concentration for each phthalate ester, a worst-case-scenario exposure was modeled. There was a statistically significant difference in the phthalate ester content between the pPVC exhibiting fungal growth and pPVC exhibiting no fungal growth for all four phthalate esters investigated. The mean phthalate ester concentration ranged from 13.74 [um]g/m2-34.94 [um]g/m2 in the pPVC exhibiting no fungal growth and 12.00 [um]g/m2-30.63 [um]g/m2 in the pPVC exhibiting fungal growth. The modeled exposure concentration in the building ranged from 0.39 [um]g/m3-0.98 [um]g/m3 and was generally lower than published exposure concentrations in similar settings.
23
Datta, Arindam. "Effects of plasticizers on extrusion of PVC: an experimental & numerical study." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54346.
Full textAbstract:
Plasticizers are often interchanged with the idea that they will not affect the processing behavior of Polyvinyl Chloride (PVC). However, when the plasticizer type is changed, various complaints are made by the processors that the material no longer processes the same. This research was concerned with the effect of three different plasticizers on the plasticating extrusion behavior of PVC. Di-isodecyl pthalate (DIDP), di-hexyl pthalate (DHP) and 2-ethyl hexyl pthalate (DOP) are the three plasticizers used in this study. First some differences in the extrusion performance of the three differently plasticized PVC compounds were identified. In particular, it was observed that pressure build-up, flow rate and power requirement were affected by the plasticizer type with the DIDP plasticized materials generating higher pressures and requiring more power than the other two plasticized materials. The differences in extrusion characteristics have been observed for two different dies (1/8 and 1/16 inch diameter) attached to the extruder. The differences were most significant between the DIDP and the DHP plasticized mixes.
Factors which could influence the processing behavior of plasticized PVC include viscosity, compaction, thermal conductivity, specific heat, and friction coefficient. It was found that all other properties other than the viscosity were unaffected by the plasticizer type. On the other hand, viscosities were significantly affected by the plasticizer type with the DIDP plasticized materials displaying higher values between 160 and 190 °C. The difference in viscosity was larger between the DIDP and DHP plasticized materials than between DIDP and DOP plasticized materials. The differences in viscosity between DIDP and DOP plasticized materials tend to diminish considerably at 190 °C. Two flow regions characterized by different degrees of fusion above and below 165 °C were identified for the plasticized PVC compounds. Plasticized PVC exhibited yield stresses with the DIDP plasticized materials having higher values. The yield stresses were responsible for the significant difference in viscosity at lower shear rates. The yield stress was a more dominant feature at temperatures below 160 °C and this fact was made use of in modeling the solids conveying zone as a fluid with yield stress. Correlation was established between the viscosities and the extrusion behavior of the plasticized PVC compounds. It was observed that the DIDP plasticized mixes had higher viscosities, fused earlier in the screw channel, gave rise to higher pressures, required more power and in general exhibited higher flow rates at the same screw speed.
The finite element method was used for the numerical simulations. Based on the experimental results, the numerical modeling of the melt zone was performed in order to predict the differences in the extrusion characteristics. The melt zones were modeled as a temperature dependent power law fluid having two different viscosity expressions above and below 165 °C. The numerical predictions for pressures and flow rates in the extruder with the 1/8 inch diameter die were in good agreement with the experimental results. For the case of the 1/16 inch diameter die attached to the extruder, the numerical and experimental flow rates were in good agreement but the pressure predictions, although indicating the correct trends, were off by 15 to 20% from the experimental results. In general the differences in the physical properties, viz. viscosities, were used to predict the differences in the pressure build-ups and flow rates. Also the solid conveying zone was modeled using a Herschel Bulkley model. It was possible to match the experimental and numerical results for the solids conveying zone by using an average density value for the entire solids conveying zone, but more work needs to be done in order to establish greater validity and applicability of this model.Ph. D.
24
Somasundaram, Deepak. "Dynamic response of polymer encased concrete walls." Birmingham, Ala. : University of Alabama at Birmingham, 2007. https://www.mhsl.uab.edu/dt/2009r/somasundaram.pdf.
Full textAbstract:
Thesis (M.S.)--University of Alabama at Birmingham, 2007.Additional advisors: Talat Abu-Amra, Robert J. Dinan, Fouad H. Fouad, Uday K. Vaidya. Description based on contents viewed July 9, 2009; title from PDF t.p. Includes bibliographical references (p. 166-169).
25
Ford, Kevin J. "Aging model for commercial polymers." Morgantown, W. Va. : [West Virginia University Libraries], 2002. https://etd.wvu.edu/etd/controller.jsp?moduleName=documentdata&jsp%5FetdId=2577.
Full textAbstract:
Thesis (M.S.)--West Virginia University, 2002.Title from document title page. Document formatted into pages; contains xii, 95 p. : ill. Includes abstract. Includes bibliographical references (p. 68-70).
26
Saunders, Justin S. "Combined effects of termiticides, volatile organic compounds, and mechanical stress on chlorinated polyvinyl chloride (CPVC)." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0013263.
Full text
27
McGovern, James Gerard. "Pathogenesis and control of infection associated with the oropharynx and the polyvinyl chloride endotracheal tube." Thesis, Queen's University Belfast, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388226.
Full text
28
Chen, Chen. "Synthesis and improvement of high performance PVC and PVDF ultrafiltration membranes." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53535.
Full textAbstract:
The applications of membrane technologies have dramatically increased during the last few decades due to technology improvement and cost reduction. Membrane applications can be found in water and wastewater treatment, pharmaceutical industry, chemical processing industry, food industry, etc. However, the membrane technology faces two major challenges: membrane fouling and membrane lifetime. During the membrane filtration process, membrane fouling caused by natural organic matter (NOM) is an inevitable phenomenon, and physical cleaning or chemical cleaning are required for recovering the performance of membrane. As a result of these cleaning processes, membrane lifetime is shortened. For this reason, it is necessary to improve membrane's fouling resistance and lifetime in order to apply membrane technology in large-scale facilities.
This dissertation focuses on improving the fouling resistance and flux performance of polyvinyl chloride (PVC) membrane and polyvinylidene fluoride (PVDF) membrane. Specifically, it is comprised of four parts. First, I prepared PVC membranes by adding different amounts of amphiphilic copolymer (Pluronic F 127) into PVC casting solutions. I optimized the performance of PVC membranes by changing the amount of Pluronic F127 used in the casting solution. The results show that with the increase of Pluronic F 127 content, the pore size and pore density both decrease. Moreover, the membrane surface becomes more hydrophilic as indicated by lower contact angles. In addition, the PVC membrane exhibits remarkable antifouling characteristics after adding Pluronic F 127. Second, I synthesized PVDF membranes by adding PVDF graft poly(ethylene glycol) methyl ether methacrylate (PEGMA) (PVDF-g-PEGMA) as additive in casting solutions via the phase inversion method. The synthesized PVDF membranes have unique pillar-like structures on surfaces, which gives the PVDF membrane a defect-free feature and allows it to generate high flux under low pressure. Third, I investigated the forming mechanism of the pillar-like structure from aspects of solvent and additive. Finally, I investigated the influence of PEGMA dose on the performance of PVDF membranes. I changed the amount of PEGMA used in the casting solution and compared the performance of the synthesized PVDF membranes.
To summarize, this dissertation has deepened our understanding of how to improve the fouling resistance and flux performance of PVC membranes and PVDF membranes by using amphiphilic copolymer. In addition, the PVDF membrane I synthesized has unique pillar-like structures that give it defect-free and high flux properties. Overall, the results of this study provide valuable information for PVC and PVDF membrane synthesis for large-scale production.
29
Garcia, Jose L. "Studies on the injection molding of Polyvinyl Chloride : analysis of viscous heating and degradation in simple geometries /." The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488193665235254.
Full text
30
Šilhánková, Lenka. "Vývoj metody pro semikvantitativní stanovení mikroplastů v půdách metodou TGA-MS." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2018. http://www.nusl.cz/ntk/nusl-376860.
Full textAbstract:
Plasty, pronikající do životního prostředí ať už neúmyslně či záměrně, mohou být fragmentovány za vzniku částic v řádu mikrometrů (tzv. mikroplastů) a znečišťovat tak půdní systémy. Doposud vyvinuté analýzy pro stanovení mikroplastů v půdách jsou především zaměřeny na kvalitativní stanovení, nicméně i jejich provedení se zatím stále potýká s různými úskalími. Navíc, téměř všechny tyto analýzy vyžadují časově náročnou předúpravu vzorku. V této studii jsme se zaměřili na vývoj nové analytické metody pro kvantitativní stanovení mikroplastů polyvinylchloridu (PVC) a polystyrenu (PS) v půdách bez předchozí úpravy vzorku pomocí termogravimetrické analýzy spojené s hmotnostní spektrometrií (TGA-MS). Pro analýzu byly použity vzorky modelové půdy s nízkým obsahem organického uhlíku, které byly spikovány na výslednou koncentraci 0,23–7 hm% PVC či PS. Vzorky byly pyrolyzovány s teplotním krokem 5 K min–1 až na teplotu 1000 °C. Pyrolýzní plynné produkty byly následně analyzovány s využitím hmotnostního spektrometru. Získaná data byla normalizována pomocí externího standardu (šťavelan vápenatý). Limity detekce se pohybovaly v rozmezí 0,08–5,3 hm% pro PVC a 0,005–0,7 hm% pro PS v závislosti na zvoleném m/z. Limity kvantifikace pak byly 0,3–17,7 hm% pro PVC a 0,002–2,2 hm% pro PS. Výsledky dokazují, že spojení TGA-MS může být konkurující semikvantitativní metodou pro stanovení mikro-PVC a mikro-PS v půdě s nízkým obsahem organického uhlíku.
31
Закусило, Роман Васильович, Роман Васильевич Закусило, Roman Vasylovych Zakusylo, and Д. Р. Закусило. "Дериватографические исследования долговечности труб из поливинилхлорида PVC−HI Type 1." Thesis, Сумський державний університет, 2016. http://essuir.sumdu.edu.ua/handle/123456789/52133.
Full textAbstract:
В связи с интенсивным научным прогрессом, различные предметы и изделия для повседневной жизни часто подвергаются изменениям для их дальнейшего улучшения и совершенствования. Поиск альтернативного материала, который по свойствам превосходил бы изначальный, является основной целью для современных инженеров. Одна из основных проблем любого современного города связана с водоканалом. Штатные металлические водопроводные трубы обладают низкой долговечностью и невысокими эксплуатационными характеристиками, что довольно усложняет процесс развития городов и народного хозяйства.
32
Djir-Sarai, Bijan. "Ökologische Modernisierung der PVC-Branche in Deutschland /." Wiesbaden : VS, Verl. für Sozialwiss, 2008. http://d-nb.info/989997197/04.
Full text
33
Fayoux, Stéphane C. "Interactions between plasticised PVC films and citrus juice components." Thesis, View thesis, 2004. http://handle.uws.edu.au:8081/1959.7/35863.
Full textAbstract:
The study presented here consists in an original piece of work to better understand complex food packaging interactions. The majority of investigations on food polymer interactions related to orange juice and this provided a good base to our study (Literature reviews: cf. Chapters 1a and b). Additionally a rather remarkable finding in 1994 was that limonin, a trace bitter material found in some varieties of orange juice was rapidly absorbed by highly plasticised polyvinyl chloride (PVC plastisol) (Chapter 2). Several commercial absorbants are available for debittering, relying on limonin absorption on the large surface area of the highly porous absorbant pellets. However, the absorptive properties of the smooth plastisols apparently relied on a different mechanism. Limonin is a very large (470.5 g/mol) compound, but some preliminary experiments with another much smaller orange juice constituent d- of absorbates in plastisols, methods used earlier (Moisan 1980, Holland and Santangelo 1988) to measure solubilities and diffusion constants in packaging films could be advantageously used to survey these properties in a wide range of materials, including model compounds of various types, and a number of compounds which may be found in citrus juices (Chapters 3, 4 and 5). Experimentally, the method found most suitable was to use a ‘test film’ of pure
plastisol which was wrapped tightly on both sides by a similar ‘supply film’ blended with 1 Molar test material (also called ‘absorbate’), setting up a concentration gradient. The inner test film was removed at regular intervals (minutes to hours) to measure (mainly by weighing) the uptake of the test reagent with time. Rather unexpectedly, it was found in a number of cases that the test film lost weight, either from the beginning, or after a period of time. Three main types of behaviour were identified: Type A lost weight from the beginning and over a long period of time, Type B gained weight initially and then lost weight, and Type C gained weight until a steady state was reached. Often the maximum, or near maximum, mass increase occurred within around 100 minutes, indicating a very rapid, liquid-like diffusion mechanism, in harmony with the rapid uptake of d-limonene and limonin. The major parameters of interest with these compounds are their diffusion rates and their solubilities, and in the presence of aqueous media (orange juice and other foodstuffs) the partition coefficient between the plastisol and water, which is related to the hydrophobicity function LogP for the compound. The major complicating factor in these measurements is the observation that the plasticiser materials themselves also migrate, in the reverse direction, because of the lower effective concentration in the supply film. This effect tends to be small, but is one explanation for the mass loss observed above, and cannot be ignored over the long
term, nor in its practical applications to contamination in foods. There are many possible applications for the techniques described above. The removal or addition of compounds in food packaging itself is one. Upgrading foods, such as orange juice, commercially, is another. In many cases ‘scalping’ off-flavours or other minor components takes place exclusively through solid or liquid contact with the packaging. The removal from the headspace measured by the current gas permeation methods is irrelevant for the vast numbers of involatile, but easily diffusable compounds. For such compounds these novel applications are simple and rapid, require little specialised equipment, and fill a niche in the armoury of food and packaging chemists.
34
Björnsdotter, Maria. "Leaching of Residual Monomers, Oligomers and Additives from Polyethylene, Polypropylene, Polyvinyl Chloride, High-density Polyethylene and Polystyrene Virgin Plastics." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-45888.
Full textAbstract:
Plastic debris are accumulating in our oceans and are degraded into smaller pieces which eventually becomes small enough to be available to lower thropic level organisms. Microplastics, commonly defined as plastic particles <5 mm, are globally distributed and found at remote locations far away from industrialized and populated areas. The effects of macro sized plastics is well understood whilst the effects of microplastics is hard to predict. It is known that microplastics act as transfer vectors for a wide range of toxic chemicals into organisms, and it is also known that the particle itself can cause toxic responses such as increased immune response and endocrine disruption. Researchers utilize virgin plastic pellets in order to determine the toxicological effect of the plastic particle itself, but resent research suggest that these virgin plastics may release chemicals that contribute to the toxic response and thus complicates the interpretation of the results. In present study, five different virgin plastics were allowed to leach in artificial seawater under conditions that mimic those used in particle toxicity studies. Plastics included were polyethylene, polypropylene, polyvinyl chloride, high-density polyethylene and polystyrene. Leachable monomers and oligomers were found in three of the five plastics tested: polyvinyl chloride, high-density polyethylene and polystyrene. Leached compounds from polyvinyl chloride were not identified due to time limitations. Aliphatic hydrocarbons in the size C14-C22 were leached out from high-density polyethylene in the concentration range 0.47 × 10-3 – 1.13 × 10-3 μg ml-1 within 24 hours. Polystyrene was found to leach styrene monomer which reached a concentration of 0.17 μg ml-1 within 24 hours.
35
Connell, David 1974. "Hazen-Williams C-factor assessment in an operational irrigation pipeline." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33737.
Full textAbstract:
In the spring of 1998, a closed end gravity flow pipeline was installed in the Lethbridge Northern Irrigation District. The pipes ranged from 900 mm to 300 mm in diameter.Manholes were placed at several locations along the pipeline and were used to install velocity meters and pressure transducers, which recorded data every second. Pressures and velocities during periods of steady state were used to calculate the head loss, Re and the Hazen-Williams friction factor, "C", along lengths of constant diameter.
The results were compared to the industry design standard of C = 150 (used for the design of rigid PVC pipe installations) and to the theoretical hydraulically smooth line developed from the Moody diagram and the Darcy-Weisbach equation. Since the maximum and minimum calculated values of C came in the 750 mm and 900 mm diameter pipes, respectively, and all other C values, including those from the 300 mm and 650 mm diameters, fell between these, pipe diameter was assumed not to be a variable. Therefore all the field data was averaged. The average value of Re for the range studied was 9.73 x 105 . The corresponding best-fit C value is 147.7, which is 6.0% lower than the derived theoretical maximum. Since the derived theoretical maximum is the ideal condition and the recorded data was slightly lower and therefore determined be a good representation of what can be expected in true field conditions.
36
Fayoux, Stéphane C. "Interactions between plasticised PVC films and citrus juice components." View thesis, 2004. http://handle.uws.edu.au:8081/1959.7/35863.
Full textAbstract:
Thesis (Ph.D.) -- University of Western Sydney, 2004.A thesis presented to the University of Western Sydney, Centre for Advanced Food Research, in fulfilment of the requirements for the degree of Doctor of Philosophy in Advanced Food Science (& Food Packaging Science). Includes bibliography.
37
Ingham, Edward John. "The development of impact toughness and resistance to slow crack growth in modified polyvinyl chloride and polyethylene pipe grade polymers." Thesis, Manchester Metropolitan University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271274.
Full text
38
Rodolfo, Junior Antonio. "Nanocompósitos de PVC, argila organicamente modificada e óxidos metálicos = estudo do processo de preparação e propriedades de combustão e emissão de fumaça." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266968.
Full textAbstract:
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia QuímicaMade available in DSpace on 2018-08-16T10:09:19Z (GMT). No. of bitstreams: 1 RodolfoJunior_Antonio_D.pdf: 6966645 bytes, checksum: 4b063523c75c2d8c912fc38efa499563 (MD5) Previous issue date: 2010
Resumo: Nanocompósitos de poli(cloreto de vinila) (PVC) flexível, com óxidos de cobre (II), molibdênio e zinco, e argila organicamente modificada (O-MMT), foram preparados utilizando-se o processo de pré-esfoliação da argila em uma mistura de plastificantes a quente, seguido da intercalação no estado fundido. Nanocompósitos de microestrutura híbrida intercalada/parcialmente esfoliada foram obtidos em todas as situações avaliadas, o que foi demonstrado diretamente pelos resultados de difratometria de raios X (DRX) e microscopia eletrônica de transmissão (MET), bem como indiretamente pelo incremento significativo do módulo de elasticidade das composições estudadas. A modelagem dos resultados de módulo de elasticidade mostrou que o processo de preparação utilizado permitiu o efetivo desenvolvimento da razão de aspecto da argila, que atingiu valores comparáveis com os obtidos por outros pesquisadores, em diferentes matrizes poliméricas e processos de preparação de seus nanocompósitos. As propriedades de combustão e emissão de fumaça, quando estudadas por calorimetria de cone em fluxo radiante de 50 kW m-2, mostraram que os óxidos metálicos possuem efeito bastante significativo, notadamente naquelas propriedades mais importantes quanto aos requisitos de segurança em situação de incêndio, retardando a liberação de calor e a emissão de fumaça das amostras estudadas, além de reduzir suas quantidades absolutas. A presença da O-MMT afeta somente de maneira discreta estas propriedades, e pouca interação foi observada na utilização conjunta destes dois aditivos. Os resultados fornecem ainda indicativos de que a combinação entre CuO e MoO3 é a que apresenta o melhor balanço de propriedades de combustão, uma vez que reduz o calor liberado e promove a supressão da fumaça de maneira mais eficiente. As formulações contendo ZnO, por conta de seu forte caráter de ácido de Lewis, indicam uma redução menos pronunciada da fumaça emitida durante o processo de combustão, quando em comparação com os óxidos de cobre (II) e molibdênio
Abstract: Poly(vinyl chloride) (PVC), copper (II), molybdenum and zinc oxides, and organically modified montmorillonite nanocomposites were prepared in a melt blending intercalation process. The morphology of the nanocomposites was evaluated using X-ray diffractometry (XRD) and transmission electron microscopy (TEM), and indirectly by the increment of the Young modulus of the formulations studied. The modeling of the Young modulus showed that the process of nanocomposite preparation allowed the increase of the aspect ratio of the clay particles, whose values were comparable to those nanocomposites obtained by other researchers, using different polymeric matrices and methodologies. Combustion and smoke emission properties, when studied using cone calorimetry at a radiant flux of 50 kW m-2, revealed that the metallic oxides have a significant effect on both combustion and smoke suppression properties, mainly those closely linked with safety in fire situations, retarding heat and smoke release, and lowering their absolute values. The presence of O-MMT only affects these properties discretely, and little interaction was observed in the joint use of these additives. Results also provide indications that the combination of the CuO and MoO3 present the best balance of combustion properties, as it reduced the heat released and promoted the suppression of smoke more efficiently. The formulations containing ZnO, because of their strong Lewis acid character, indicated a less pronounced reduction of smoke released during the combustion process, when compared with copper (II) and molybdenum oxides
Doutorado
Ciencia e Tecnologia de Materiais
Doutor em Engenharia Química
39
LIMA, JÚNIOR Francisco Alves de. "Estudo do efeito da orientação molecular nas propriedades mecânicas de tubos em policloreto de vinila (PVC)." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/17936.
Full textAbstract:
Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-09-28T19:19:22Z
No. of bitstreams: 2
license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5)
Dissertação PPGEM - Francisco Alves de Lima Júnior.pdf: 7760423 bytes, checksum: b0d747f5e3c3795b57483f19b676a178 (MD5)Made available in DSpace on 2016-09-28T19:19:22Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação PPGEM - Francisco Alves de Lima Júnior.pdf: 7760423 bytes, checksum: b0d747f5e3c3795b57483f19b676a178 (MD5) Previous issue date: 2016-02-03
A pesquisa que deu origem a esta dissertação foi realizada a partir de dados de propriedades mecânicas obtidos de testes e ensaios de inspeção, performance e controle de qualidade, executados em tubos fabricados em material polimérico, com e sem orientação molecular. Foram eles: Resistência ao Impacto, Resistência à Pressão Hidrostática Interna, Grau de Gelificação e Resistência ao Cloreto de Metileno, Resistência à Compressão Diametral, Estabilidade Dimensional, Classe de Rigidez e Resistência ao Achatamento, Resistência o Prolongamento da Fissura e Grau de Orientação Molecular. Para obtenção dos dados, os materiais foram testados em condições reais e extremas de operação, em sistemas, equipamentos, instrumentos, “softwares” e acessórios especificados, montados e calibrados em laboratório e instalações fabris, conforme normativos técnicos. Para registros dos dados foram utilizados sistemas informatizados acessórios aos equipamentos, assim como planilhas eletrônicas e “softwares” de controle estatístico e descritivo e para parametrização de ensaios mecânicos. Os dados e resultados foram analisados segundo parâmetros e critérios de estabilidade dimensional, tenacidade e rigidez, resistência à pressão hidrostática interna, ao impacto, ao cloreto de metileno, à compressão diametral e ao prolongamento de fissura, associados ao seu grau de orientação molecular, baseados em bibliografias e normas técnicas referentes às análises, ensaios e materiais empregados. Estes critérios abrangem o dimensionamento, cálculo e comparação de parâmetros, quando do material aplicado ao projeto de tubos. Foram avaliados os efeitos resultantes da orientação molecular nas propriedades mecânicas finais dos produtos acabados. Foi observado que o processo de orientação molecular proporcionou ao material maior tenacidade, maior resistência à transmissão da fissura, bem como maiores resistências a fadiga, impacto, tração, compressão e deformação, maior módulo de elasticidade, e consequente diminuição de coeficientes de segurança aplicados ao projeto.
The research that led to this work was made from data obtained mechanical properties testing and inspection testing, performance and quality control, performed in tubes made of polymer material, with or without molecular orientation. They were: Impact Resistance, Resistance Pressure Internal Hydro, Grade Gelling and resistance Methylene Chloride, Resistance Diametral compression, dimensional stability, Class of stiffness and resistance to flattening, resistance to extension of the fissure and Molecular Orientation degree. To obtain the data, the materials have been tested in real and extreme operating conditions, systems, equipment, instruments, “software” and accessories specified, assembled and calibrated in laboratory and manufacturing facilities, as technical regulations. For data records were used computer accessories systems for equipment, as well as spreadsheets and statistical and descriptive control “software” for parameter setting and mechanical tests. The data and results were analyzed according to parameters and dimensional stability criteria, toughness and rigidity, resistance to internal hydrostatic pressure, impact, methylene chloride, diametral compression and extension cleft associated to the degree of molecular orientation, based in technical bibliographies and rules regarding analyzes, testing and materials used. These criteria cover the design, calculation and parameters comparison, when the material applied to the pipe design. The effects resulting from the molecular orientation in the final mechanical properties of finished products. It was observed that the molecular orientation process provided the material greater toughness, greater resistance to the transmission of the crack, as well as higher resistance to fatigue, impact, tensile, compression and creep, higher modulus, and thus reduce safety coefficients applied to project.
40
Bandaru, Venkata Raghava Sunil Kumar Reddy. "Deformation and Durability Studies of Insulation Polymers." University of Akron / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=akron1227191899.
Full text
41
鄧善均 and Shin-kwan Andrew Tang. "Analysis of di(2-ethylhexyl) phthalate in polyvinyl chloride and monosodium glutamate in foodstuff using high performance liquidchromatography and the investigation of microwave digestion method forpaint analysis." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1989. http://hub.hku.hk/bib/B31209452.
Full text
42
Kim, Taehwan. "Preventing Thermal Degradation of Pvc Insulation by Mixtures of Cross-Linking Agents and Antioxidants." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1157547/.
Full textAbstract:
Poly(vinyl chloride)(PVC) wire and cable insulation has poor thermal stability, causing the plasticizer to separate from the PVC chain and produce an oily residue, lowering the tensile elongation at break and thus increasing brittleness. We have added 4 wt.% of three different types of cross-linking agents and antioxidants, as well as mixtures of both, to improve the thermal stability of the plasticizer and tensile properties of PVC after thermal exposure. We performed tensile tests, tribological tests, profilometry, scanning electron microscopy(SEM) and water absorption determination before and after thermal exposure at 136 ℃ for 1 week. After adding the agents, elongation at break increased by 10 to 20 % while the wear rate and water absorption were lower than for the control sample. Less voids are seen in the SEM images after adding these two kinds of agents. The thermal resistance of the PVC cable insulation is best enhanced by combinations of cross-linking agents and antioxidants.
43
Pathak, Pooja. "Microscopic Investigations of the Adhesion of Bacteria and Algae on Biomaterial Surfaces." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1176473803.
Full text
44
Haj-Mahmoud, Qasem M. (Qasem Mohammed). "Pyrolysis Capillary Chromatography of Refuse-Derived Fuel and Aquatic Fulvic Acids." Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc331124/.
Full textAbstract:
Pyrolysis-capillary gas chromatography combined with FID, ECD and MS detection were used to characterize refuse-derived fuel and aquatic fulvic acids. Different pyrolysis methods and programs were evaluated. Pyrolysis temperatures of 700-800°C produced the strongest signal for organics present in RDF and fulvic acid. Cellulose and fatty acids pyrolyzates were identifiable by GC-MS following preparative pyrolysis fractionation. At organic chloride content of 0.023%, only three halogenated compounds were detected in the GC-MS of the fractions. None of the priority pollutants were detected at lower detection limit of 0.72 to 24 mg/ kg RDF. Selective solvent extraction improves the reproduciblities of the technique and allows the detection of polymeric structures. Pyrograms of polyvinyl chloride and regular typing paper showed some common peaks that are present in the RDF pyrogram. About 65% of the peaks in the RDF pyrogram might be of paper origin. The organic chloride content of the RDF was evaluated by ion chromatography of the trapped pyrolyzates in 2% NaOH trap and it was found to be 221 mg Cl/ kg dry RDF.
Pyrolysis conditions and temperature programs for FA were systematically evaluated. Samples included purified FA, methylated FA and HPLC separated fractions. Characteristic pyrograms were developed. Profiles of benzene, toluene, phenol, m-cresol and biphenyl from FA were evaluated. The production of phenol was the largest at 800°C, at concentration of 1.61 mg per gram of FA pyrolyzed. The profiles of benzene and toluene followed the same pathways. Both pyrolyzates had at least two precursors. HPLC fractions of FA showed some regular retention patterns characteristic of polymeric material. DL-proline, seriene and vanillic acid pyrograms showed some peaks with the same retention times as those in FA pyrogram under the same conditions. A reproducibility of 6% relative standard deviation was achieved in the pyrolysis of RDF and 0.91% in the case of FA.
45
Tang, Shin-kwan Andrew. "Analysis of di(2-ethylhexyl) phthalate in polyvinyl chloride and monosodium glutamate in foodstuff using high performance liquid chromatography and the investigation of microwave digestion method for paint analysis /." [Hong Kong : University of Hong Kong], 1989. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12720434.
Full text
46
Zouhri, Yassir. "Amélioration du procédé de synthèse de polychlorure de vinyle par décomposition catalytique de peroxydes." Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR017.
Full textAbstract:
L'accélération de la polymérisation en suspension du monomère chlorure de vinyle (VCM) par amorçage de peroxyde à l’aide d’un système redox a été étudié ainsi que son impact sur les propriétés du polychlorure de vinyle (PVC) qui en résulte. Ce projet s'inscrit dans le cadre d'une collaboration CIFRE entre la société Vynova-Mazingarbe et l'équipe MOCAH du Laboratoire UCCS de l'université de Lille. L'amorçage de la polymérisation est basé sur la formation de radicaux par décomposition redox d'un pré-amorceur peroxyde, induite par un activateur à deux composants, appelé "kicker". Cet activateur consiste en un dérivé organométallique en quantité catalytique, le catalyseur, qui réduit le peroxyde et provoque sa décomposition, combiné à un agent réducteur capable de régénérer la forme oxydée du catalyseur. Une étape de développement préliminaire a été réalisée sur le 1-chlorobutane en tant que modèle du monomère VCM, afin de fournir une première évaluation de l'effet de l’amorçage redox avec le kicker avant sa mise en œuvre en polymérisation du VCM en suspension. Une série de catalyseurs à base de fer, de type ferrocène (Fc) et ses dérivés ont été évalués, combinés à une série d'agents réducteurs hydrosolubles, pour la décomposition des pré-amorceurs di-(2-éthylhexylperoxydicarbonate) (EHP) ou peroxyde de lauroyle (LPO). Lorsqu’ils ont été utilisés pour la polymérisation en suspension du VCM, une amélioration significative de la vitesse a été obtenue en utilisant le système kicker Fc/Rongalite ou decamethylferrocene/Rongalite en présence des peroxydes EHP ou LPO. L'utilisation d’un agent de transfert de phase visant à améliorer le contact entre les constituants du kicker situés dans différentes phases du milieu réactionnel a également été examinée; l'agent de transfert de phase bromure de cétyltriméthylammonium utilisé dans cette étude s’est avéré capable d’améliorer les performances du kicker Fc/Rongalite dans certaines conditions optimisées. D'autres agents réducteurs, dont certains nouveaux, appartenant à la famille des sulfinates et potentiellement plus solubles en phase organique ont également été synthétisés, en utilisant la Rongalite comme produit de départ. Au sein de cette famille, tous les dérivés et en particulier le N-perfluoroéthane α-aminométhanesulfinate de dicyclohexylammonium, ont montré en combinaison avec le ferrocène une bonne efficacité pour accélérer la vitesse de polymérisation tout en préservant la stabilité du milieu réactionnel et les propriétés du polymère finalThe acceleration of radical suspension polymerization of vinyl chloride monomer (VCM) by peroxide initiation using a redox system has been investigated as well as its impact on the properties of the resulting polyvinyl chloride (PVC). This project is part of a CIFRE collaboration between the company Vynova-Mazingarbe and the MOCAH team of the UCCS Laboratory of the University of Lille. The initiation of the polymerization was based on the formation of radicals via redox decomposition of a peroxide pre-initiator, promoted by a dual-component activator, so-called “kicker”. This kicker consists of an organometallic derivative in catalytic amount, the catalyst, that reduces the peroxide and causes its decomposition combined with a reducing agent, which is able to regenerate the oxidized form of the catalyst. A preliminary development stage was carried out on a model monomer of VCM, 1-chlorobutane, to provide a first evaluation of the effect of redox initiation with the kicker before being applied in the suspension polymerization of VCM. A series of iron-based catalysts, mainly ferrocene (Fc) and its derivatives, combined with a range of water-soluble reducing agents, have been evaluated toward the decomposition of di-(2-ethylhexylperoxydicarbonate) (EHP) or lauroyl peroxide (LPO) as pre-initiators. When applied to the suspension polymerization of VCM, a significant improvement in rate has been achieved using Fc/Rongalite or decamethylferrocene/Rongalite as kicker in the presence of EHP or LPO. The use of a phase transfer agent to improve the interaction between the kicker compounds located in different phases has also been examined; the cetyltrimethylammonium bromide phase transfer agent used in this study has been shown to further improve the performance of the Fc/Rongalite kicker under certain optimized conditions. Other reducing agents, including some new ones, belonging to the family of sulfinates and potentially more soluble in the organic phase have been synthesized, using Rongalite as a starting product. Within this family, all compounds, in particular dicyclohexylammonium N-perfluoroethane α-aminomethanesulfinate, have shown a good efficiency in accelerating the rate of polymerization when combined with Fc in the presence of EHP peroxide, while preserving the stability of the reaction medium as well as the properties of the resulting polymer
47
Switzer, Jackson Reeves. "Three applications of green chemistry in engineering: (1) silylamines as reversible ionic liquids for carbon dioxide capture; (2) carbon dioxide as protecting group in chemical syntheses; (3) mitigating the thermal degradation of polyvinyl chloride." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/52173.
Full textAbstract:
Green chemistry principles served as a guide for three industrially-relevant projects. In the first project, silylamines were applied as reversible ionic liquids for carbon dioxide capture from post-combustion flue gas streams. The effect of silylamine structure was thoroughly researched to develop a comprehensive library of silylamines and an accompanying set of structure-property relationships. The proposed solvent systems have the potential to present significant energy savings, as design has focused on their use in a non-aqueous, solvent-free environment. The second project also dealt extensively with carbon dioxide capture, as a reversible, in-situ protecting group for amines. Three strategies for the reversible protection of amines using carbon dioxide were developed and evaluated. Further, a chemoselective reaction was performed using carbon dioxide to protect a reactive amine and consequentially direct reactivity elsewhere within the same molecule. The carbon dioxide-protection technology developed has significant impact in multi-step industrial syntheses, as reversible, in-situ protection with carbon dioxide could eliminate the need for separate protection and deprotection unit operations. Lastly, a study was performed on the thermal degradation and stabilization of PVC in the presence of both plasticizers and thermal stabilizers. The study combined both model compound experiments as well as work with bulk PVC blends to gain a holistic understanding of the processes that take place during the degradation and stabilization of PVC. A bio-based plasticizer was investigated as a replacement for petroleum-based phthalate plasticizers. Additionally, two novel thermal stabilizers for PVC were presented and evaluated.
48
Vess, Lora Elizabeth 1972. "The Politics of PVC." Thesis, University of Oregon, 2007. http://hdl.handle.net/1794/6195.
Full textAbstract:
xv, 277 p. A print copy of this title is available from the UO Libraries, under the call number: SCIENCE TP1180.V48 V46 2007This dissertation examines the political, scientific, social, environmental, and health debates surrounding the use of polyvinyl chloride (commonly called vinyl), a plastic many public health advocates and activists contend has a toxic lifecycle with deleterious human and ecological impacts at every stage. Using extensive documentary research and in-depth interviews, I answer a basic question: how and why have major stakeholders politicized PVC in recent decades? I find the strength of the anti-PVC movement lies largely in its broad based constituency: it includes professionals within the health care and green building industries, as well as labor unions and environmental health advocates. However, I raise critical questions about the movement's strategy of situating itself as a market-based movement where limited analysis is given to the greater environmental and health impacts of the health care and building industries as a whole.
Adviser: Gregory McLauchlan
49
Brasil, Edneide Morais. "Atividade antimicrobiana de filmes de policloreto de vinila (PVC) reforçado com nanopartículas de prata imobilizadas em sílica /." Araraquara, 2019. http://hdl.handle.net/11449/183628.
Full textAbstract:
Orientador: Marcos David FerreiraResumo: Objetivo. Analisar a eficácia antimicrobiana in vitro de compósito em pó a base de prata e sua aplicação em diferentes concentrações em filmes de policloreto de vinila (PVC) produzidos em escala industrial e em laboratório. Métodos. Um material compósito constituído por dióxido de sílicio (SiO2) e nanopartículas de prata (NpAg), produzido e cedido por uma empresa de soluções tecnológicas, foi caracterizado por Microscopia Eletrônica de Varredura (MEV), Espectroscopia no Infravermelho com Transformada de Fourier (FTIR) e Difração de Raio X (DRX). Filmes de PVC industrial aditivados com 6,25, 12,5, 25 e 100 ppm de NpAg e filmes produzidos laboratorialmente pelo método de casting aditivados com 12,5, 25 e 100 ppm de NpAg foram caracterizados por Microscopia Eletrônica de Varredura (MEV), Espectroscopia no Infravermelho com Transformada de Fourier (FTIR) e Difração de Raio X (DRX). Testes microbiológicos in vitro foram realizados com o compósito de prata e com os filmes de PVC. Com o compósito realizou-se o Teste de Difusão em Ágar por poço e a Contagem de Microrganismos Viáveis. Com os filmes industrial e laboratorial realizou-se o teste da Norma JIS Z 2801:2000, e com os filmes industriais realizou-se os testes de Agitação em Frasco e Contagem de Microrganismos Viáveis. Resultados. O compósito apresentou inibição para Escherichia coli em todas as concentrações estudadas e para Staphylococcus aureus nas concentrações de 12,5, 25 e 100 ppm de NpAg. A adição de compósito na matriz... (Resumo completo, clicar acesso eletrônico abaixo)
Mestre
50
NEVES, LUCIO P. "Desenvolvimento e caracterização de câmaras de ionização cilíndricas como sistemas de referência para dosimetria de feixes de radiação de fótons." reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10545.
Full textAbstract:
Made available in DSpace on 2014-10-09T12:41:43Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T14:08:28Z (GMT). No. of bitstreams: 0
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
FAPESP:10/01070-4