Дисертації з теми "Polylactide- Synthesis"
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Nelson, Warren W. "Synthesis and Characterization of Polylactide/Polyimide Blends." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1282575053.
Повний текст джерелаRagheb, Ragy Tadros. "Synthesis and Characterization of Surface-Functionalized Magnetic Polylactide Nanospheres." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/26719.
Повний текст джерелаPh. D.
Lindman, Jonas. "Synthesis of functional polylactide : Monomer synthesis scale-up and poly(ethylene glycol) functionalization." Thesis, KTH, Skolan för kemivetenskap (CHE), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-207175.
Повний текст джерелаI detta examensarbete optimerades en syntesväg till en funktionaliserad laktid genom att öka utbytet från 25 till 33 % samt minska antalet enhetsoperationer från 17 till 10 st. Detta gjordes genom att anpassa en befintlig syntesväg till tillverkning i större skala. Monomeren sampolymeriserades även med ʟ-laktid och funktionaliserades genom att polyetylenglykol av varierande kedjelängd fästes till polylaktidkedjan, vilket gav en hämmande effekt på celladheransen till materialets yta. Det resulterande materialet: En funktionaliserad polylaktid, är ett intressant material som lämpar sig för användning i medicinska implantat, mycket tack vare sin mångsidighet och möjligheten att utforma materialen för specifika ändamål.
Jing, Feng. "Synthesis and characterization of polylactide derivatives with high glass transition temperatures." Diss., Connect to online resource - MSU authorized users, 2006.
Знайти повний текст джерелаRagheb, Ragy. "Synthesis and Characterization of Polylactide-siloxane Block Copolymers as Magnetite Nanoparticle Dispersion Stabilizers." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/31687.
Повний текст джерела
The synthesis of the triblock copolymers is comprised of three reactions. Difunctional, controlled molecular weight polymethylvinylsiloxane oligomers with either aminopropyl or hydroxybutyl endgroups were prepared in ring-opening redistribution reactions. These oligomers were utilized as macroinitiators for ring-opening L-lactide to provide triblock materials with polymethylvinylsiloxane central blocks and poly(L-lactide) endblocks. The molecular weights of the poly(L-lactide) endblocks were controlled by the mass of L-lactide relative to the moles of macroinitiator. The vinyl groups on the polysiloxane center block were further functionalized with carboxylic acid groups by adding mercaptoacetic acid across the pendent double bonds in an ene-thiol free radical reaction. The carboxylic acid functional siloxane central block was designed to bind to the surfaces of magnetite nanoparticles, while the poly(L-lactide)s served as tailblocks to provide dispersion stabilization in solvents for the poly(L-lactide). The copolymers were complexed with magnetite nanoparticles by electrostatic adsorption of the carboxylates onto the iron oxide surfaces and these complexes were dispersible in dichloromethane. The poly(L-lactide) tailblocks extended into the dichloromethane and provided steric repulsion between the magnetite-polymer complexes.
Master of Science
Bolakhrif, Sabah. "Synthesis and application of PLA and PLA/GO fibers through thermo-responsive transformation of PLA particles." Thesis, KTH, Skolan för kemivetenskap (CHE), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-207578.
Повний текст джерелаRieger, Jutta. "Synthesis, characterization and biomedical interest of amphiphilic biocompatible and bioeliminable (glyco)copolymers of various architectures." Université Joseph Fourier (Grenoble), 2006. http://www.theses.fr/2006GRE10038.
Повний текст джерелаThis work mainly aims at modifying the surface of polymer nanoparticles (NP) by novel biocompatible amphiphilic copolymers, composed of hydrophilic ethylene oxide (EO) units and hydrophobic ε-caprolactone (CL) units. Copolymers of different architectures have been considered, i. E. , diblock copolymers, graft copolymers and star-shaped copolymers. Poly(ethylene oxide) chains α-terminated by an ε-caprolactone group and ω-end-capped by a methoxy group (γPEO. CL) were synthesized and used, (i) as PEO macromonomers that were copolymerized by ring-opening polymerization (ROP) with ε-caprolactone (ε-CL) to give PCL-g-PEO graft copolymers, and (ii) as precursors for a AB-double headed PEO chain, that were used to initiate selectively the polymerization of two different monomers to form an ABC mikto-arm star copolymer. The amphiphilic PEO/PCL diblock and graft copolymers were used as stabilizers and surface modifiers of polymer nanoparticles (NP). The effect of the copolymer structural features (architecture, composition and amount) on the formation and structure of the NP was investigated. The complement activation, i. E. , the stealthiness of the nanoparticles, as a function of the composition and architecture of the copolymer used as a stabilizer was studied. Another challenge of this work was to decorate the surface of such NP by mannose moieties, which are suitable targeting probes for dendritic, mannose-receptor expressing cells. Therefore, mannose derivatives were covalently attached as α-end-group to poly(ε-caprolactone) and PEO-b-PCL diblock copolymers. It was found that the NPs' surface properties were strongly related to the glyco(co)polymers used for their preparation
Balasubramaniam, Sharavanan. "Synthesis, Characterization and Structure-Property Relationships of Polymer-Stabilized Nanoparticles Containing Imaging and Therapeutic Agents." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/55119.
Повний текст джерелаPh. D.
Jiang, Xuwei. "Synthesis and properties of comb-like polylactides." Diss., Connect to online resource - MSU authorized users, 2006.
Знайти повний текст джерелаPrebe, Arnaud. "Different routes for synthesis of Poly(lactic acid) : silicon-based hybrid organic-inorganic nanomaterials and nanocomposites." Lyon, INSA, 2010. http://theses.insa-lyon.fr/publication/2010ISAL0015/these.pdf.
Повний текст джерелаL’acide polylactique génère depuis quelques années un engouement certain puisqu’il apparaît comme un des biopolymères les plus aptes à remplacer les polymères issus de l’industrie pétrolière. Toutefois, afin de pouvoir prétendre remplacer ces polymères dans les applications tel que l’emballage, etc. , les propriétés mécanique se doivent d’être au moins égale. Il est maintenant bien reconnu qu’il est possible d’accroitre une multitude de propriété en nanostructurant à l’aide d’une phase inorganique les polymères. Cependant il existe plusieurs possibilité quand au procédé choisi. Ici on se propose d’étudier la production d’un nanocomposite à base d’acide polylactique et d’une phase inorganique siliconée en utilisant différentes voies de production. En premier lieu, la synthèse in-situ du PLA en présence de silice pyrogénée a été étudiée tout en faisant varier la compatibilité par la fonctionnalisation en surface. Ensuite la génération de la phase inorganique à partir de précurseur alkoxysilane a été menée directement dans l’acide polylactique fondu par extrusion réactive avec l’ajout ou non d’agent d’interface. Puis les deux voies ont été combinées afin de générer la phase inorganique dans le monomère fondu (L-Lactide) puis de polymériser celui-ci dans le même réacteur. Enfin ces trois voies ont été comparées entre elles et avec le simple mélangeage dans le fondu de silice pyrogénée avec l’acide polylactique en extrusion
Petzetakis, Nikolaos. "Crystallisation driven self-assembly of polylactide containing block copolymers synthesised by combination of ROP and RAFT." Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/55160/.
Повний текст джерелаBiernesser, Ashley B. "Synthesis of Diverse Degradable Polymers by Redox-Switchable Iron-Based Catalysis:." Thesis, Boston College, 2017. http://hdl.handle.net/2345/bc-ir:107403.
Повний текст джерелаChapter 1. Poly(lactic acid) (PLA) is a biodegradable polymer derived from renewable resources that has garnered much interest in recent years as an environmentally friendly substitute to conventional petroleum-derived engineering polymers. PLA has many applications in textiles, packaging, compostable consumables, and biomedical devices, as PLA displays excellent biocompatibility. This polymer is primarily produced from the ring-opening polymerization of lactide, a cyclic dimer of lactic acid. This introductory chapter highlights mechanistic features of this ring-opening polymerization reaction as well as metal-based catalysts that have been reported for lactide polymerization. In addition, switchable catalysis is an emerging field that has gained interest with polymer chemists for the potential of creating original polymer compositions and architectures. The utilization of redox-switchable catalysis to control lactide polymerization is discussed in this chapter. Chapter 2. Bis(imino)pyridine iron bis(alkoxide) complexes have been synthesized and utilized in the polymerization of (rac)-lactide. The activities of the catalysts were particularly sensitive to the identity of the initiating alkoxide with more electron-donating alkoxides resulting in faster polymerization rates. The reaction displayed characteristics of a living polymerization with production of polymers that exhibited low molecular weight distributions, linear relationships between molecular weight and conversion, and polymer growth observed for up to fifteen sequential additions of lactide monomer to the polymerization reaction. Mechanistic experiments revealed that iron bis(aryloxide) catalysts initiate polymerization with one alkoxide ligand, while iron bis(alkylalkoxide) catalysts initiate polymerization with both alkoxide ligands. Oxidation of an iron(II) catalyst precursor lead to a cationic iron(III) bis(alkoxide) complex that was completely inactive towards lactide polymerization. When redox reactions were carried out during lactide polymerization, catalysis could be switched off and turned back on upon oxidation and reduction of the iron catalyst, respectively. In addition, preliminary investigations of copolymerization reactions of lactide with ethylene are reported. Chapter 3. A cationic iron(III) complex is active for the polymerization of various epoxides, whereas the analogous neutral iron(II) complex is inactive. Cyclohexene oxide polymerization could be "switched off" upon in situ reduction of the Fe(III) complex and “switched on” upon in situ oxidation, which is orthogonal to what was observed previously for lactide polymerization. Conducting copolymerization reactions in the presence of both monomers resulted in block copolymers whose identity can be controlled by the oxidation state of the complex: selective lactide polymerization was observed in the iron(II) oxidation state and selective epoxide polymerization was observed in the iron(III) oxidation state. Evidence for the formation of block copolymers was obtained from solubility differences, GPC, and DOSY-NMR studies. Chapter 4. Formally iron(I) bis(imino)pyridine monoalkoxide complexes were synthesized through protonolysis of a bis(imino)pyridine iron alkyl species with p-methoxyphenol or neopentyl alcohol. The resulting complexes were characterized by X-ray crystallography, 1H NMR, EPR, and Mössbauer spectroscopy, and preliminary characterization of the electronic structure of these complexes is discussed. These iron complexes were found to be highly active catalysts for the polymerization of various cyclic esters and carbonates, with the iron mono(neopentoxide) complex being much more active and giving more narrow molecular weight distributions than the mono(aryloxide) complex. The bis(imino)pyridine iron neopentoxide complex was highly active in particular for the polymerization of ε-caprolactone (CL), giving full conversion within 10 minutes at room temperature in toluene, making it one of the most active iron complexes reported for this transformation ([Fe]:[CL] = 1:2000). Comparison of the polymerization activity of these iron mono(alkoxide) complexes with the analogous iron(II) bis(alkoxide) complexes is reported
Thesis (PhD) — Boston College, 2017
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
Bentz, Kyle C. "Synthesis and Characterization of Linear and Branched Polylactic Acid for Use in Food Packaging Applications." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/578.
Повний текст джерелаScherger, Carolyn Scherger. "Synthesis and Functionalization of Polyesters and Poly(ester carbonate)s Based on 3-Hydroxypropionic Acids." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1530201553516796.
Повний текст джерелаBanu, Ionut. "Modeling and optimization of tubular polymerization reactors." Phd thesis, Université Claude Bernard - Lyon I, 2009. http://tel.archives-ouvertes.fr/tel-00719401.
Повний текст джерелаRitch, Grayson D. "Synthesis, Characterization, and Reactivity of Novel Zinc Coordination Complexes." Kent State University Honors College / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1399675758.
Повний текст джерелаBASILISSI, LUCA. "SYNTHESIS OF PLA HOMO AND COPOLYMERS AND THEIR NANOCOMPOSITES FOR ADVANCED MATERIALS." Doctoral thesis, Università degli Studi di Milano, 2012. http://hdl.handle.net/2434/168372.
Повний текст джерелаAbert, Jessica Verfasser], Horst [Akademischer Betreuer] Fischer, and Rainer [Akademischer Betreuer] [Telle. "Synthese neuartiger Verbundwerkstoffe für den Knochenersatz aus Calciumphosphaten, Calciumcarbonaten und Polylactiden und deren mechanische und biologische Eigenschaften / Jessica Abert ; Horst Fischer, Rainer Telle." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1162499389/34.
Повний текст джерелаAbert, Jessica [Verfasser], Horst Akademischer Betreuer] Fischer, and Rainer [Akademischer Betreuer] [Telle. "Synthese neuartiger Verbundwerkstoffe für den Knochenersatz aus Calciumphosphaten, Calciumcarbonaten und Polylactiden und deren mechanische und biologische Eigenschaften / Jessica Abert ; Horst Fischer, Rainer Telle." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1162499389/34.
Повний текст джерелаStehnová, Ivana. "Vliv chemické struktury změkčovadla na vlastnosti bioplastu na bázi polyhydroxybutyrátu." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2018. http://www.nusl.cz/ntk/nusl-438891.
Повний текст джерелаTruong, Minh Chau, and Minh Chau Truong. "Synthesis Polylactide with Varying Molecular Weights." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/16667460668781130230.
Повний текст джерела國立臺灣科技大學
材料科學與工程系
102
In this thesis, polylactide with various molecular weights and molecular weight distributions were synthesized by solution ring opening polymerization. Molecular weight was controlled by varying the ratio of L-lactide monomer to palmityl alcohol initiator and tin(II) octanoate was used as a catalyst for precise control over molecular weight. Anhydrous toluene was used as a non-reactive solvent to prevent the contamination of catalyst. Besides, we also try to obtain the standard molecular weight of PLA (greater than 100,000 g/mol) to compare with commercial PLAs. Properties of different molecular weights of PLA were characterized by gel permeation chromatography, thermogravimetric analysis, differential scanning calorimety, and 1H NMR spectroscopy.
Lun, Liu I., and 劉依綸. "Synthesis and Gamma Irradiation Effects on Polylactide." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/42321841474193894576.
Повний текст джерела國立陽明大學
醫學工程研究所
90
Because of the excellent biocompatibility and biodegradability of polylactide (PLA), medical products made of PLA, such as sutures, have been used for about 30 years. Therefore, the safety of this kind of material has been confirmed. One of the major differences between biomaterials and ordinary materials is that biomaterials require strict sterilization treatment. The sterilization process should be chosen very carefully, to avoid causing any severe damages of the products. The effects of gamma irradiation on PLLA have been examined using electron paramagnetic resonance (E.P.R.) spectroscopy. By analyzing the decay curves of the E.P.R. signal intensities for PLLA annealed at various temperatures, one can study the reaction kinetics of free radicals generated by γ irradiation. The E.P.R. spectrum of γ- irradiated PLLA (irradiated at room temperature) show a quartet pattern, suggesting that free radicals produced by hydrogen abstractions from methine groups. This kind of free radicals may cause crosslinking. Free radicals decay in vacuum can be fitted well as a second order reaction. The fitting is even better if the reaction is modeled by a modified second order reaction. Free radicals decay in air can be fitted well as a first order reaction. The reaction rate constants of free radicals increase with increasing temperature, while decrease with increasing doses of exposure. Results of thermal analysis of DSC indicate that γ-irradiation has little effects on the melting temperature, Tm, of the specimens, while the glass transition temperature, Tg, decreases with increasing dose. The results suggest that the chain scissions due to gamma irradiation are mainly occurred at the amorphous regions of the polymer.
林威任. "Synthesis of Cross-linked Micelles for Anticancer Drug Delivery from Poly(ethylene glycol)- functional polylactide." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/65112277355203133684.
Повний текст джерела逢甲大學
纖維與複合材料學系
104
Micelles have been frequently used as carriers for drug delivery. In general, micelles suffered from severe problems regarding their colloidal stability in human blood, which appreciably limits their clinical applicability. In this context, crosslinked micelles consisting of biodegradable polyethylene glycol-b-polylactide were prepared to enhance the colloidal stability of resulting micelles. To introduce covalently bonded crosslinkages into micelles, polyethylene glycol-b-poly(allyl functional polylactide-co- polylactide) (PEG-b-poly(ALA-co-LA)), a biodegradable amphiphilic copolymer, have been synthesized via a rational synthetic route. The chemical structures of PEG-b-poly(ALA-co-LA) were well analyzed through various analysis methods. Following the synthesis, the PEG-b-poly(ALA-co-LA)s a were changed from amphiphilic copolymers to non-crosslinked micelles (NCLMs). Sequentially, these NCLMs were crosslinked via UV-induced radical chain polymerization, resulting in the crosslinked micelles (CLMs). In PBS buffer , CLMs were observed to have enhanced colloidal stability than NCLMs according to their change in particle size and particle uniformity. The in vitro drug release results indicated that CLMs released their loaded drugs in a slower and more sustained manner as compared with NCLMs. Moreover CLMs displayed insignificant cytotoxicity in MES-SA cells. As a consequence, CLMs have been verified as a non-toxic and highly biocompatible material for the use of biodegradable carriers.
Lin, Hui-Mei, and 林惠美. "Synthesis of Biodegradable and Biocompatible Polyurethane/urea Containing Polylactiode Diol." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/dg5gyq.
Повний текст джерела國立中興大學
化學工程學系所
99
In this study, we have combined the chemical processing of PLA-diol-2000 into polyurethanes (PUs) in our design of new green materials. PLA-diol-2000 of 1,800 molecular weight was synthesized from 1,4-butanediol and L-lactide through ring-opening polymerization, and was used as the key component of soft segment of PUs. Other common raw materials used in our formulation developments were diol of polyethylene-butylene-adipate (RS-956), polytetramethylene ether glycol (PTMEG), isophorone diisocyanate (IPDI), 1,4-butanediol (1,4-BDO) and 1,4-butanediamine (1,4-BDA). The suitable process for synthesis of PUs with PLA-diol-2000 was studied, and the characteristics of synthesized PUs containing PLA-diol-2000 were analyzed, including molecular weights, thermal properties and mechanical properties. From this study, we have come up with PUs possessing balanced properties that exhibit excellent biocompatibility and biodegradability. This is achieved by the combination of PLA-diol-2000/PTMEG/RS-956 (in ratio of 1/1/3, respectively) as the soft segment constituents with BDO and BDA (in ratio of 1/1, respectively) as the hard segment ingredients in our formulation. The green materials show great potential for use in the special medical applications.
Chen, Yi-An, and 陳奕安. "Synthesis and Characterization of Polylactic Acid(PLA) and Waterborne Polyurethanes and Application on Inorganic Materials Dispersion Properties." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/48953813278764671557.
Повний текст джерела國立臺灣大學
高分子科學與工程學研究所
102
Different kinds and constructions of polyurethanes are synthesized with different diisocyanates, polyols and chain-extenders by polycondensation in this research. And then, synthesized polyurethanes are made to stable dispersants according to suitable solvents. After all dispersants are synthesized, we discussed their characterizations, and interforces with several gathered inorganic materials which can be dispersed well in indicate dispersants. Synthesis and application of dispersants are mainly divided into two parts. The first part is about synthesization of star shape and comb shape Polylactic Acid Polyurethane(PLA-PU) dispersants. Since buying PLA on the market is not easy, we use direct synthesization in this research. PLA polyol are synthesized with Lactic acid and ethylene glycol by dehydration and polymerization. After PLA polyol are synthesized, star shape dispersants are centered with Trimethylolpropane and comb shape dispersants are centered with Xylitol, and both are synthesized with Isophorone diisocyanate(IPDI) and finally with different proportions of PLA polyol, Poly Ethylene Glycol(PEG) and Poly Properlene Glycol(PPG) in the branches. Grain-shape materials like TiO2 and SiO2 are well-dispersed in these PLA-PU dispersants. In order to check the effects in dispersants, the samples are examined by Transmission Electron Microscope(TEM), Dynamic Light Scattring(DLS) and several instruments in this research, which proved that Grain-shape materials are well-dispersed in PLA-PU dispersants. For applications, these PLA-PU dispersants can be added in spray, dye and ink etc. for its excellent and exact dispersion effects even if the solutions stand for a long time. The second part is about synthesization of waterborne polyurethanes(WPU) dispersants with IPDI, different proportions of PEG, PPG, and finally chain-extenders by emulsification and polymerization. Layer inorganic materials are dispersed in these WPU dispersants, like graphite can be dispersed to several slices of graphene. In order to check the effects in dispersants, the samples are examined by TEM, X-ray Diffraction(XRD), UV/VIS Spectrophotometer and several instruments in this research, which proved that layer inorganic materials are well-dispersed in these WPU dispersants. For applications, these WPU dispersants can be added in pigments, electronic materials, lubricants and several industrial materials for dispersants can promote inorganic materials’ thermal property, conductivity, transparency and many properties.