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Artykuły w czasopismach na temat "Mercerization"
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Nishimura, Hisao, i Anatole Sarko. "Mercerization of cellulose. IV. Mechanism of mercerization and crystallite sizes". Journal of Applied Polymer Science 33, nr 3 (20.02.1987): 867–74. http://dx.doi.org/10.1002/app.1987.070330315.
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Liu, Jie, i Fumei Wang. "Influence of Mercerization on Micro-structure and Properties of Kapok Blended Yarns with Different Blending Ratios". Journal of Engineered Fibers and Fabrics 6, nr 3 (wrzesień 2011): 155892501100600. http://dx.doi.org/10.1177/155892501100600308.
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To investigate the effect of mercerization on micro-structure and the properties of kapok/cotton blended yarns. FTIR spectra and x-ray diffraction (XRD) results, moisture regains and mechanical properties of blended yarns were compared before and after mercerization. The results show that mercerization treatment did not have an obvious effect on chemical compositions of cellulose, but did lead to decreasing on crystallinity of blended yarns, and transformed certain portion of cellulose I into cellulose II. When the NaOH concentration increased from 180g/L to 250 g/L, the strengths of blended yarns increased and elongations at breaking declined, and the extent of changes were lessened gradually with the increase of kapok fiber content, when the NaOH concentration further reached 280g/L, the strengths of blended yarns with high content of kapok fiber dropped dramatically, and elongations at breaking increased gradually, while hygroscopicities of blended yarns increased significantly. Different from cotton fiber, a more moderate alkali treatment condition should be chosen in mercerization process for kapok fiber.
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Wakida, Tomiji, Muncheul Lee, Sun Ji Park i Aya Hayashi. "Hot Mercerization of Cottons." FIBER 58, nr 8 (2002): 304–7. http://dx.doi.org/10.2115/fiber.58.304.
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El Oudiani, A., Y. Chaabouni, S. Msahli i F. Sakli. "Mercerization ofAgave americanaL. fibers". Journal of the Textile Institute 103, nr 5 (maj 2012): 565–74. http://dx.doi.org/10.1080/00405000.2011.590010.
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El-Sayed, Ihab, i S. M. Saleh. "Effect of Spinning Systems on Properties of Dyed Egyptian Cotton Yarns after Mercerization Treatment". Research Journal of Textile and Apparel 19, nr 4 (1.11.2015): 48–56. http://dx.doi.org/10.1108/rjta-19-04-2015-b005.
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The effects that spinning technology and spinning parameters have on the color strength (K/S), strength, and breaking elongation of post dyed and mercerized yarns are investigated in this study. The emphasis of the study is on the selection of long stable Egyptian cotton varieties, namely Giza 80, Giza 86, and extra long stable Giza 92. The cotton samples are spun by using compact, ring, and open end spinning technologies. For the purpose of this study, different yarn counts and twist multipliers are used. The mechanical properties, such as the tensile strength and breaking elongation of the produced yarn are investigated and compared before and after the mercerization treatment (slack and tension), followed by a reactive dyeing process. All of the samples are prepared for dyeing after mercerization. The dyeing performance in terms of the K/S is studied. When the results are examined, it is found that the samples that have undergone (bleaching + slack mercerization + reactive dyeing) generally have higher K/S values than samples that have undergone (bleaching + tension mercerization + reactive dyeing) and (bleaching + non-mercerization + reactive dyeing) respectively. Open-end spun yarns have a higher K/S compared to the compact and ring spun yarns with the lowest count yarn and twist level. The strength percentages are higher for compact, then ring and finally open-end spun yarns respectively with tension mercerization. There is no noticeable difference in the elongation% for all of the treatment processes. The authors have used quality engineering reproducibility and repeatability (R&R) tools to guarantee the repeatability and reproducibility of the results in this research paper.
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Okano, T., i A. Sarko. "Mercerization of cellulose. II. Alkali–cellulose intermediates and a possible mercerization mechanism". Journal of Applied Polymer Science 30, nr 1 (styczeń 1985): 325–32. http://dx.doi.org/10.1002/app.1985.070300128.
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Chowdhury, Muksit Ahamed, Sonia Hossain i Konica Jannat Fatema. "Single Step Mercerization and Formaldehyde-Free Polyfunctional Finishing on Cotton Fabrics". AATCC Journal of Research 8, nr 4 (1.07.2021): 28–35. http://dx.doi.org/10.14504/ajr.8.4.5.
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Mercerization, the treatment of cotton with concentrated sodium hydroxide under tension, is performed to enhance absorption, luster, strength and dimensional stability. After mercerization, the unreacted sodium hydroxide is neutralized with acids. Neutralization with polycarboxylic acids (PCAs) is likely not only to crosslink the cellulose molecules, but to also enhance other functional attributes like crease recovery behavior, flame retardancy, and soil release properties. In this research, four PCAs with different functional groups were used for fabric neutralization to merge mercerization and poly- functional finishing into one continuous process. The PCA treated fabrics were then assessed for their performance. All four PCAs were effective in improving crease recovery and soil release properties, and reducing the flammability, of the treated cotton fabric.
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da Silva Nicolau, Géssica, Ricardo Pondé Weber, Sergio Neves Monteiro, Gabriela Azevedo Loureiro, Amanda Assis Lavinsky, Letícia Vieira da Fonseca, Eduardo Gonçalves da Silva, Pedro Luiz Barrozo dos Santos, Rodrigo Pereira Abranches i Vinícius Cordeiro Machado. "Influence of Mercerization Process on the Surface of Coconut Fiber for Composite Reinforcement". Materials Science Forum 1012 (październik 2020): 37–42. http://dx.doi.org/10.4028/www.scientific.net/msf.1012.37.
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The high consumption of green coconut water, especially in tropical countries like Brazil, generates an aggravating factor to the environment, which is associated with the waste generated after its consumption. Thus, one of the possible ways of reusing the coconut shell after consumption is through the extraction of its fibers, which are considered for several applications. In general, natural lignocellulosic fibers (NLFs) have been used for many purposes, such as reinforcement filler in composite materials, since they have low cost and good mechanical properties. With the intention of providing a better compatibility between the NLFs and the composite polymeric matrix, different types of surface treatments are carried out on the fibers, including mercerization, a chemical treatment in which a basic solution is used. In this sense, the present work aims to verify the influence of mercerization with 3% sodium hydroxide (NaOH) on coconut fiber. Among the analyses carried out, stands the scanning electron microscope (SEM) on fresh and treated coconut fibers. The SEM analyses, allowed to observe that after treatment via mercerization, the fibers displayed a greater surface roughness. This indicates the partial removal of lignin, hemicellulose and some other extracts present on the outer layer of the coconut fiber. Therefore, mercerization will probably enable a better mechanical anchoring between fiber and matrix. Results obtained suggest the effectiveness of the mercerization process. However, it was also of concern that such treatment tends to generate NaOH residues, which is a negative factor regarding sustainability.
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Li, Dan Xi, i Quan Xiao Liu. "Characterization of Mercerized Straw Pulp Fiber". Advanced Materials Research 1030-1032 (wrzesień 2014): 450–53. http://dx.doi.org/10.4028/www.scientific.net/amr.1030-1032.450.
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On the base of the former research of mercerization of pulp fibers, SEM, XRD and Automated Surface Area & Pore Size Analyzer were used to characterize surface morphology, crystalline property, and specific surface area and the pore size distribution of fibers. The results show that the fiber cell wall swelling, degree of crystallinity decrease and specific surface area and pore size distribution increase after mercerization.
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Revol, J. F., A. Dietrich i D. A. I. Goring. "Effect of mercerization on the crystallite size and crystallinity index in cellulose from different sources". Canadian Journal of Chemistry 65, nr 8 (1.08.1987): 1724–25. http://dx.doi.org/10.1139/v87-288.
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Native cellulose samples having a wide range of crystallinity and crystallite size were mercerized by treatment with sodium hydroxide. The resultant cellulose II samples showed only a narrow range of crystallinity and an essentially constant crystallite size. For the low-crystallinity samples, crystallinity and crystallite size actually increased on mercerization. These results are in line with the proposal that mercerization involves the mingling of chains from adjacent and antiparallel cellulose I microfibrils to form cellulose II crystals of antiparallel chains.
Rozprawy doktorskie na temat "Mercerization"
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Almlöf, Heléne. "Extended Mercerization Prior to Carboxymethyl Cellulose Preparation". Licentiate thesis, Karlstads universitet, Avdelningen för kemiteknik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-5947.
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Carboxymethyl cellulose (CMC) is produced commercially in a two-stage process consisting of a mercerization stage, where the pulp is treated with alkali in a water alcohol solution, followed by an etherification stage in which monochloroacetic acid is added to the pulp slurry. In this thesis an extended mercerization stage of a spruce ether pulp was investigated where the parameters studied were the ratio of cellulose I and II, concentration of alkali, temperature and retention time. The influence of the mercerization stage conditions on the etherification stage, were evaluated as the degree of substitution (DS) of the resulting CMC and the filterability of CMC dissolved in water at a concentration of 1%. The DS results suggested that the NaOH concentration in the mercerization stage was the most important of the parameters studied. When the NaOH concentration in the mercerization step was low (9%), a high cellulose II content in the pulp used was found to have no negative impact on the DS of the resulting CMC compared with pulps with only cellulose I. However, when the NaOH concentration was high (27.5%), pulps with high content of cellulose II showed a lower reactivity than those with only cellulose I with respect to the DS of the CMC obtained after a given charge of NaMCA. The results obtained from the filtration ability study of CMC water solutions suggested that both the amount of cellulose II in the original pulp and the temperature had a negative influence on the filtration ability whereas the NaOH concentration in the mercerization stage had a positive influence. The filtration ability was assumed to be influenced highly by the presence of poorly reacted cellulose segments. A retention time between 1-48 h in the mercerization stage had no effect on either the DS or the filtration ability of the CMC. Using NIR FT Raman spectroscopy molecular structures of CMC and its gel fraction were analyzed with respect to the conditions used in the extended mercerization stage. Here it was found that the alkaline concentration had a very strong influence on the following etherification reaction. FT Raman spectra of CMC samples and their gel fractions prepared with low NaOH concentrations (9%) in the mercerization stage indicated an incomplete transformation of cellulose to Na-cellulose before carboxymethylation to CMC. Low average DS values of the CMC, i.e. between 0.42 and 0.50, were yielded. Such CMC dissolved in water caused very thick and semi solid gum-like gels, probably due to an uneven distribution of substituting groups along the cellulose backbone. FT Raman spectra of CMC mercerized with alkaline concentrations at 18.25 and 27.5% in the mercerization stage indicated, however, that all of the cellulose molecules were totally transferred to CMC of high DS, i.e. between 0.88 and 1.05. When dissolved in water such CMC caused gels when they were prepared from ether pulp with a high fraction of cellulose II.
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Almlöf, Ambjörnsson Heléne. "Mercerization and Enzymatic Pretreatment of Cellulose in Dissolving Pulps". Doctoral thesis, Karlstads universitet, Institutionen för ingenjörs- och kemivetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-26960.
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This thesis deals with the preparation of chemically and/or enzymatically modified cellulose. This modification can be either irreversible or reversible. Irreversible modification is used to prepare cellulose derivatives as end products, whereas reversible modification is used to enhance solubility in the preparation of regenerated cellulose. The irreversible modification studied here was the preparation of carboxymethyl cellulose (CMC) using extended mercerization of a spruce dissolving pulp. More specifically the parameters studied were the effect of mercerization at different proportions of cellulose I and II in the dissolving pulp, the concentration of alkali, the temperature and the reaction time. The parameters evaluated were the degree of substitution, the filterability and the amount of gel obtained when the resulting CMC was dissolved in water. Molecular structures of CMC and its gel fractions were analysed by using NIR FT Raman spectroscopy. It was found that the alkali concentration in the mercerization stage had an extensive influence on the subsequent etherification reaction. FT Raman spectra of CMC samples and their gel fractions prepared with low NaOH concentrations (9%) in the mercerization stage indicated an incomplete transformation of cellulose to Na-cellulose before carboxymethylation to CMC. Low average DS values of the CMC, i.e. between 0.42 and 0.50 were obtained. Such CMC dissolved in water resulted in very thick and semi solid gum-like gels, probably due to an uneven distribution of substituents along the cellulose backbone. FT Raman spectra of CMC samples and their gel fractions mercerized at higher alkaline concentration, i.e. 18.25 and 27.5% in the mercerization stage, indicated on the other hand a complete transformation of cellulose to Na-cellulose before carboxymethylation to CMC. Higher average DS values of the CMC, i.e. between 0.88 and 1.05 were therefore obtained. When dissolved in water such CMC caused gel formation especially when prepared from dissolving pulp with a high fraction of cellulose II. The reversible modification studied was the dissolution of cellulose in NaOH/ZnO. Here the effect of enzyme pretreatment was investigated by using two mono-component enzymes; namely xylanase and endoglucanase, used in consecutive stages. It was found that although the crystallinity and the specific surface area of the dissolving pulp sustained minimal change during the enzymatic treatment; the solubility of pulp increased in a NaOH/ZnO solution from 29% for untreated pulp up to 81% for enzymatic pretreated pulp.Baksidetext Cellulose can be chemically and/or enzymatically modified. Irreversible modification is used to prepare cellulose derivatives as end products, reversible modification to enhance solubility in the preparation of regenerated cellulose. The irreversible modification studied here was the preparation of carboxymethyl cellulose (CMC) using extended mercerization of a spruce dissolving pulp. More specifically the parameters studied were the effect of mercerization at different proportions of cellulose I and II in the dissolving pulp, the concentration of alkali, the temperature and the reaction time. It was found that the alkali concentration in the mercerization stage had an extensive influence on the subsequent etherification reaction. The content of cellulose II had little effect on degree of substitution (DS) at low NaOH concentration, but tended to decrease DS at higher NaOH concentration in both cases compared with cellulose I. It was also found that the content of cellulose II correlates with the gel formation obtained when the CMC is dissolved in water. The reversible modification studied was the dissolution of cellulose in NaOH/ZnO. Here the effect of enzyme pretreatment was investigated by using two mono-component enzymes; namely xylanase and endoglucanase, used in consecutive stages. It was found that the solubility of pulp increased in a NaOH/ZnO solution from 29% for untreated pulp up to 81% for enzymatic pretreated pulp.
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Wu, Xinyu Wu. "Control of the mechanical behavior of bacterial cellulose by mercerization". Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case151092096578873.
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Aono, Hajime. "Structures and rheological properties of plant cellulose/LiCl・DMAc solutions and the effect of mercerization". Kyoto University, 2006. http://hdl.handle.net/2433/136488.
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Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第12530号
農博第1573号
新制||農||930(附属図書館)
学位論文||H18||N4167(農学部図書室)
UT51-2006-K253
京都大学大学院農学研究科森林科学専攻
(主査)教授 松本 孝芳, 教授 中坪 文明, 教授 西尾 嘉之
学位規則第4条第1項該当
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Pires, Flauzino Neto Wilson. "Etude morphologique des nanocristaux de cellulose et application nanocomposite". Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAI003/document.
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Puisque cette thèse présente deux études indépendantes sur les nanocristaux de cellulose, le résumé a été divisé en deux sections qui font référence aux chapitres II et III, respectivement.Investigation morphologique et structurelle des nanocristaux de cellulose I et II préparés par hydrolyse à l'acide sulfuriqueLe but du travail de recherche présenté dans le chapitre II était de produire, de caractériser et de comparer les CNC obtenus à partir de la pâte de bois d'eucalyptus en utilisant trois méthodes différentes: i) l'hydrolyse classique à l'acide sulfurique (CN-I), ii) l'hydrolyse acide de la cellulose précédemment mercerisée par traitement alcalin (MCN-II), et iii) la solubilisation de la cellulose dans l'acide sulfurique et la recristallisation subséquente dans l'eau (RCN-II). Les trois types de CNC préparés présentent des morphologies et des structures cristallines différentes. Lorsque les conditions d'hydrolyse acide sont mises en place de telle sorte que les domaines cristallins dans la pâte de bois initial et la cellulose mercerisée (WP et MWP, respectivement) sont préservés (60 wt% H2SO4, 45°C, 50 min), les nanocristaux résultants conservent la nature fibrillaire des fibres d’origine (c'est-à-dire que l'axe de la chaîne est parallèle au grand axe des particules aciculaires) et leur type allomorphe initial (I pour WP et II pour la MWP). Dans les deux cas, les particules sont principalement composées de quelques cristallites élémentaires liées latéralement. Les nanocristaux unitaires dans les CNC préparés à partir de cellulose mercerisée (MCN-II) sont plus courts, mais plus larges que ceux préparés à partir des fibres de cellulose I (CN-I). Si des conditions plus sévères sont considérées (64 wt% H2SO4, 40°C, 20 min), ce qui entraîne la dépolymérisation et la dissolution de la cellulose native, les chaînes courtes recristallisent en rubans de Cell-II lors de la régénération dans l'eau à température ambiante. Dans ces rubans tortueux, l'axe de la chaîne serait perpendiculaire au grand axe du nanocristal et parallèle à son plan basal.La structure moléculaire et cristalline unique des nano-rubans implique qu'un nombre plus élevé d'extrémités de chaîne réductrice sont situées à la surface des particules, ce qui peut être important pour des modifications chimiques subséquentes et pour de potentielles applications spécifiques telles que la biodétection et la bio-imagerie. Donc, cette étude permet de mieux comprendre la structure cristalline et la morphologie de la CNC obtenue par régénération à l'acide sulfurique.Propriétés mécaniques de nanocomposites de caoutchouc naturel renforcé avec des nanocristaux de cellulose à facteur de forme élevé extraits de la coque de sojaDans cette étude, les CNCs ont été isolés des coques de soja à partir d’un traitement par hydrolyse avec de l'acide sulfurique. Ces CNCSH ont été utilisés comme phase de renfort dans une matrice NR par casting à différents taux de charge, à savoir 1, 2.5 et 5% en poids. Les effets des CNCSH sur la structure ainsi que sur les propriétés thermiques et mécaniques du NR ont été étudiés. Par exemple, en ajoutant seulement 2,5% en poids de CNC, le module de conservation en traction du nanocomposite à 25 °C est environ 21 fois plus élevé que celui de la matrice NR non chargée. Cet effet de renfort est supérieur à celui observé pour les CNCs extraits d'autres sources. Il peut être attribué non seulement au facteur de forme élevé de ces CNCs, mais aussi à la rigidité du réseau percolant de nanoparticules formé au sein de la matrice polymère. De plus, il a été constaté que la sédimentation des CNC pendant la mise en œuvre du film nanocomposite par casting joue un rôle crucial sur les propriétés mécaniques. Une contribution importante de ce travail est de mettre en évidence l'importance de la sédimentation des CNCs, pendant l'étape d'évaporation sur les propriétés mécaniques des nanocomposites, ce qui est rarement mentionné dans la littératureSince this thesis presents two independent studies on cellulose nanocrystals, the abstract was divided in two sections referring to chapters II and III, respectively.Comprehensive morphological and structural investigation of cellulose I and II nanocrystals prepared by sulfuric acid hydrolysisCellulose nanocrystals (CNCs) were produced from eucalyptus wood pulp using three different methods: i) classical sulfuric acid hydrolysis (CN-I), ii) acid hydrolysis of cellulose previously mercerized by alkaline treatment (MCN-II), and iii) solubilization of cellulose in sulfuric acid and subsequent recrystallization in water (RCN-II). The three types of CNCs exhibited different morphologies and crystal structures that were characterized using complementary imaging, diffraction and spectroscopic techniques. CN-I corresponded to the type I allomorph of cellulose while MCN-II and RCN-II corresponded to cellulose II. CN-I and MCN-II CNCs were acicular particles composed of a few laterally-bound elementary crystallites. In both cases, the cellulose chains were oriented parallel to the long axis of the particle, although they were parallel in CN-I and antiparallel in MCN-II. RCN-II particles exhibited a slightly tortuous ribbon-like shape and it was shown that the chains lay perpendicular to the particle long axis and parallel to their basal plane. The unique molecular and crystal structure of the RCN-II particles implies that a higher number of reducing chain ends are located at the surface of the particles, which may be important for subsequent chemical modification. While other authors have described nanoparticles prepared by regeneration of short-chain cellulose solutions, no detailed description was proposed in terms of particle morphology, crystal structure and chain orientation. Was provide such a description in the present document.Mechanical properties of natural rubber nanocomposites reinforced with high aspect ratio cellulose nanocrystals isolated from soy hullsCellulose nanocrystals (CNCs) were isolated from soy hulls by sulfuric acid hydrolysis. The resulting CNCs were characterized using TEM, AFM, WAXS, elemental analysis and TGA. The CNCs have a high crystallinity, specific surface area and aspect ratio. The aspect ratio (around 100) is the largest ever reported in the literature for a plant cellulose source. These CNCs were used as a reinforcing phase to prepare nanocomposite films by casting/evaporation using natural rubber as matrix. The mechanical properties were studied in both the linear and non-linear ranges. The reinforcing effect was higher than the one observed for CNCs extracted from other sources. It may be assigned not only to the high aspect ratio of these CNCs but also to the stiffness of the percolating nanoparticle network formed within the polymer matrix. Moreover, the sedimentation of CNCs during the evaporation step was found to play a crucial role on the mechanical properties
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Varol, Cihangir. "Caustic Recovery From Highly Alkaline Denim Mercerizing Wastewaters Using Membrane Technology". Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609855/index.pdf.
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Recovery of caustic solution from mercerizing wastewaters of a denim producing textile mill was performed by using membrane technologies. A comprehensive characterization study was conducted to develop the treatment scheme. Highly
alkaline and warm condition of wastewater has induced using membranes made of Polyethersulfone (PES). Conducted pretreatment applications such as microfiltration, flocculation and centrifuge have been found unsuccessful to improve further treatment capacities. Hence recovery studies which are UF, NF and pilot-system membrane applications have been implemented without any pretreatment. Effects of TMP and CFV on UF and NF processes were investigated and optimum operating conditions have been defined. UF has accomplished almost complete caustic solution recovery beside high COD and color retentions 84 % and 94 % under 4.03 bar TMP and 0.79 m/s CFV at 20±2 0C. Because of higher capacity of NF membranes also in acid and alkali recovery area, NF process has been studied in addition to UF. NF has also provided nearly complete NaOH recoveries with 92 % COD and 98 % color retentions under 4.03 bar TMP and 0.79 m/s CFV at 20±
2 0C. Furthermore temperature effect was also studies by repeating the same processes at 40±
2 0C considering the real operating conditions. Temperature has affected the system performance positively with regards to flux increases with insignificant loses in recovery and retention capacities. Lastly a pilot plant study has been conducted and it was found successful despite some operational difficulties due to high inorganic content and temperature of wastewater.
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Gomes, Bianca Lovezutti. "Pré-tratamento e sacarificação da fibra de curauá". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/75/75135/tde-05072017-163804/.
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O cenário energético mundial traz à tona a necessidade da busca por fontes renováveis que contribuam de maneira positiva para a diminuição de emissões de gases nocivos, como o CO2. Neste contexto estudos como o presente constituem importante contribuição para o melhor entendimento destas questões ambientais, para tanto o mesmo teve como objetivo avaliar o efeito de pré-tratamento com solução alcalina aquosa (mercerização, NaOH 20%, 20 g.L-1, temperatura ambiente, 5h) sobre a sacarificação, via hidrólise ácida e enzimática de fibras lignocelulósicas de curauá (Teor de: umidade 8,2% ±0,2, cinzas 2,0% ±0,1, holocelulose 85,9% ±0,7, hemiceluloses 15,5% ±0,2, α-celulose 70,4% ±0,2, lignina total de 9,4% ±0,3 e índice de cristalinidade (Ic) 69,4%. Alíquotas retiradas durante a mercerização foram caracterizadas, por exemplo, a alíquota referente a 2h apresentou as seguintes propriedades: α-celulose 81,6% ±0,2, lignina total 3,2% ±0,3 e índice de cristalinidade (Ic) 75,5%. Análises de microscopia eletrônica de varredura (MEV), comprimento e espessura médio (MorFi) mostraram, ao longo da mercerização, aumento de rugosidade e fragmentos aderidos a superfície da fibra, e diminuição de comprimento e espessura. Fibras não tratadas e tratadas (2h) foram submetidas a hidrólise ácida (1:30 vol./massa, H2SO4 a 24%, 80°C, 6h), onde as fibras não reagidas foram separadas do licor via filtração, e caracterizadas por difração de raios X, MEV, MorFi, e os açúcares do licor e produtos de decomposição foram analisados via Cromatografia líquida de alta eficiência (CLAE). Os resultados da hidrólise ácida com a fibra mercerizada, apresentaram maior produção de glicose (fração celulósica) e diminuição dos teores de xilose e arabinose, (fração hemicelulósica). A glicose atingiu teor máximo de 2,68 g.L-1, no entanto para a hidrólise com a fibra não tratada atingiu um máximo de 1,3 g.L-1, com formação em baixa escala de produtos de decomposição (HMF e furfural). Fibras de partida e mercerizada também foram submetidas a hidrólise enzimática (48h, enzimas celulase comercial-Accellerase 1500, 0,5mL/g). Alíquotas das polpas não reagidas e licor foram extraídas durante a reação, e caracterizadas conforme descrito para hidrólise ácida. Microscopias mostraram que houve aumento da rugosidade e da abertura dos feixes de fibras nas fibras mercerizadas. Os valores de Ic apresentaram aumento inicial e posterior queda indicando hidrólise da fração não cristalina da celulose seguida da fração cristalina. O comprimento e espessura médio das fibras, sofreram diminuição, sendo mais acentuada na hidrólise com a fibra mercerizada e mais intenso para a espessura. Houve formação de glicose e xilose e não houve formação de produtos de decomposição como ocorrido na hidrólise ácida. A fibra não tratada apresentou um máximo de 12,0 g.L-1 de glicose e 2,30 g.L-1 de xilose, já a fibra mercerizada apresentou máximos de 17,5 g.L-1, 1,36 g.L-1 de glicose e xilose respectivamente, indicando aumento de 45% de glicose e diminuição de 56% de xilose. Esta investigação do efeito da mercerização sobre a sacarificação da fibra de curauá forneceu informações importantes para o aprofundamento deste estudo, assim como indicou que o curauá pode posteriormente se tornar fonte de produção de etanol de segunda geração.The global energy scenario brings to light the need for the search for renewable sources that contribute positively to the reduction of harmful gases emission, such as CO2. In this context, studies such as the one herein constitute an important contribution to a better understanding of these environmental issues. The purpose of this study was to evaluate the effect of the alkaline pre-treatment (mercerization, NaOH 20%, 20 g.L-1, room temperature, 5h) on saccharification, via acid and enzymatic hydrolysis of curauá lignocellulosic fibers (moisture content 8.2% ± 0.2, ashes 2.0% ± 0.1, holocellulose 85.9% ±0.7, hemicellulose 15.5% ±0.2, α-cellulose 70.4% ± 0.2, total lignin 9.4% ± 0.3 and crystallinity index, (Ic, 69.4%). Aliquots removed during mercerization were characterized. For example, the aliquot referring to 2h had the following properties: α-cellulose 81.6% (± 0.2), total lignin 3.2% (± 0.3) and crystallinity index (Ic) 75.5%. Analyses of scanning electron microscopy (SEM), length and average thickness (MorFi) showed increased roughness and fragments adhered to the fiber surface and a decrease in length and thickness throughout the mercerization. Untreated and treated fibers (2h) were subjected to acid hydrolysis (1:30 vol./M.H2SO4 24%, 80°C, 6h), in which the unreacted fibers were separated from the liquor via filtration, and then characterized by X-ray diffraction, MEV, MorFi; liquor sugars and decomposition products were analyzed via High Performance Liquid Chromatography (HPLC). The results of the acid hydrolysis with the mercerized fiber presented higher glucose production (cellulose fraction) and decreased xylose and arabinose contents (hemicellulosic fraction). The maximum glucose content obtained was 2.68 g.L-1, while for the hydrolysis with the untreated fiber the maximum was 1.3 g.L-1, in which there was low-scale formation of decomposition products (HMF and furfural). No mercerized and mercerized fibers were also subjected to enzymatic hydrolysis (48h, commercial cellulase enzymes-Accellerase 1500, 0.5mL / g). Aliquots of the unreacted pulps and liquor were extracted during the reaction, and then characterized as described for acid hydrolysis. Microscopies showed that there was an increase in roughness and in the opening of fiber bundles in the mercerized fibers. The crystallinity indexes showed an initial increase and a subsequent decrease indicating hydrolysis of the non-crystalline fraction of the cellulose followed by the crystalline fraction. The length and average thickness of the fibers decreased, which was more accentuated in the hydrolysis with the mercerized fiber and more intense as for the thickness. There was formation of glucose and xylose and there was no formation of decomposition products as occurred in acid hydrolysis. For the untreated fiber, a maximum glucose of 12.0 gL-1 and 2.30 gL-1 of xylose was obtained, whereas the mercerized fiber presented a maximum of 17.5 gL-1, 1.36 gL-1 of glucose and xylose respectively, indicating a 45% increase in glucose and a 56% decrease in xylose. This investigation of the effect of mercerization on the saccharification of the curauá fiber provided important information for further studies, as well as indicating that the curauá can later become a source of second generation ethanol production. Keywords: Curauá Fiber. Mercerization. Acid and Enzymatic Hydrolysis. Glucose.
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Yaniga, Bradley S. "Mitigation of the Tomato Lye Peeling Process". Connect to Online Resource-OhioLINK, 2007. http://www.ohiolink.edu/etd/view.cgi?acc_num=toledo1180634446.
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Thesis (M.S.Ch.E.)--University of Toledo, 2007.Typescript. "Submitted as partial fulfillment of the requirements for The Master of Science in Chemical Engineering. " Bibliography: leaves 134-142.
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Quajai, Sirisart, i soj@kmitnb ac th. "Biopolymer Composite based on Natural and Derived Hemp Cellulose Fibres". RMIT University. Applied Sciences, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20061222.111612.
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The aim of this research was to study the effect of pre-treatment and modification processes on the properties of hemp cellulose fibre for biopolymer composites application. Hemp fibres have been modified by various extraction, swelling, chemical and enzymatic treatments. The morphology and mechanical properties of the modified fibres have been measured. Biopolymer composites have been prepared using the modified fibres and matrices of cellulose acetate butyrate and cellulose solutions derived from hemp. The first fibre treatment employed was acetone extraction and mercerization. A low pressure acrylonitrile grafting initiated by azo-bis-isobutylonitrile was performed using alkali treated fibre. The AN grafted fibres had no transformation of crystalline structure as observed after mercerization. The mechanical properties performed by a single fibre test method were strongly influenced by the cellulose structure, lateral index of crystallinity, and fraction of grafting. Bioscouring of hemp using pectate lyase (EC 4.2.2.2), Scourzyme L, was performed. Greater enzyme concentration and a longer treatment improved the removal of the low methoxy pectin component. Removal of pectate caused no crystalline transformation in the fibres, except for a slight decline in the X-ray crystalline order index. Smooth surfaces and separated fibres were evidence of successful treatment. The shortening of fibre by grinding and ball-milling was introduced to achieve a desired fibre size. An increase in the milling duration gradual ly destroyed the crystalline structure of the cellulose fibres. An increase in solvent polarity, solvent-fibre ratio, agitation speed and drying rate resulted in the rearrangement of the ball-milled cellulose crystalline structure to a greater order. The thermal degradation behaviour of hemp fibres was investigated by using TGA. The greater activation energy of treated hemp fibre compared with untreated fibre represented an increase in purity and improvement of structural order. The all hemp cellulose composites were prepared by an introduction of fibres into 12% cellulose N-methyl-morpholine N-oxide (NMMO) solution and water-ethanol regeneration. A broadening of the scattering of the main crystalline plane, (002) and a depression of the maximum degradation temperature of the fibres were observed. These revealed a structural change in the fibres arising from the preparation. The mechanical properties of composites depended on size, surface area, crystallinity and the structural swelling of the fibres. Composites of cellulose acetate butyrate (CAB) and modified hemp fibres were prepared. Composites containing pectate lyase enzyme treated fibres showed better mechanical property improvement than untreated and alkali treated fibres respectively.
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Campos, Rejane Daniela de. "Influência da mercerização e irradiação por feixe de elétrons na aderência da fibra do ouriço da castanha do Brasil em matriz de polietileno de alta densidade". Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-17112015-141935/.
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O interesse na utilização de fibras naturais com matrizes poliméricas para a preparação de compósitos espalhou-se rapidamente ao longo dos últimos anos. No entanto, a adesão interfacial entre a fibra e a matriz tem ainda de ser aperfeiçoada. Para melhorar a adesão entre os constituintes e, consequentemente as propriedades mecânicas e térmicas dos materiais, duas abordagens foram investigadas: a irradiação por feixe de elétrons e a mercerização. Este trabalho descreve a fabricação e caracterização de biocompósitos de polietileno de alta densidade e fibra do ouriço da castanha do Brasil que foram preparadas por duas metodologias diferentes: a primeira foi irradiar o compósito com 150 kGy e a segunda foi irradiar a matriz com 15 kGy e então produzir o compósito. Para ambas as metodologias foram utilizadas fibras naturais mercerizadas e não mercerizadas. O efeito dos tratamentos estudados para melhorar a adesão entre a fibra e a matriz polimérica foi avaliado através de caracterizações mecânica, química, térmica e morfológica. Com base neste estudo, observou-se que a fibra do ouriço da castanha do Brasil é um material tecnicamente viável para uso como reforço em compósitos poliméricos. Observou-se que o processo de irradiação da matriz seguida da produção dos compósitos é um método eficaz para melhorar as propriedades térmicas e mecânicas dos compósitos biopoliméricos e que, quando comparado com o processo de mercerização, esse método pode ser considerado mais ambientalmente correto (sem produtos químicos e sem geração de resíduo), mais barato e mais simples.The interest in the use of natural fibres with polymeric matrix for the preparation of composite spread rapidly over the last years. However, the interfacial adhesion between the fiber and the matrix has to be improved. To improve the adhesion between the constituents and consequently the mechanical and thermal properties of materials, two approaches were investigated: electron beam irradiation and mercerization. This paper describes the fabrication and characterization of biocomposites compounds with high density polyethylene and fibre from Brazil nut pod that were prepared by two different methods: the first irradiating the composite with 150 kGy and the second was radiating matrix with 15 kGy and then produce the composite. For both methodologies, natural fibers, mercerized and non-mercerized were used. The effect of the treatments to improve adhesion between the fiber and the polymer matrix was evaluated through mechanical, chemical, thermal and morphology charcterization. Based on this study, it was observed that fibre from Brazil nut pod is a technically viable material for use as reinforcement in polymer composites. It was observed that the process of matrix irradiation followed by the composite fabrication is an effective method for improving the thermal and mechanical properties of the composites, when compared with mercerization process, this method can be considered more environmentally friendly (no chemicals, and without generating waste), cheaper and simpler.
Części książek na temat "Mercerization"
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Gooch, Jan W. "Mercerization". W Encyclopedic Dictionary of Polymers, 451. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_7314.
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Gooch, Jan W. "Slack Mercerization". W Encyclopedic Dictionary of Polymers, 670. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_10729.
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Sarko, Anatole, Hisao Nishimura i Takeshi Okano. "Crystalline Alkali-Cellulose Complexes as Intermediates During Mercerization". W ACS Symposium Series, 169–77. Washington, DC: American Chemical Society, 1987. http://dx.doi.org/10.1021/bk-1987-0340.ch009.
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Zheng, Shuwang, i Xianhua Song. "Market Effect on the Voluntary Disclosure of Internal Control Information Due to Different Mercerization Degree". W Communications in Computer and Information Science, 415–21. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-23023-3_63.
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Campos, Rejane D., Maria Sotenko, Mahesh Hosur, Shaik Jeelani, Francisco R. V. Díaz, Esperidiana A. B. Moura, Kerry Kirwan i Emilia S. M. Seo. "Effect of Mercerization and Electron-Beam Irradiation on Mechanical Properties of High Density Polyethylene (HDPE)/Brazil Nut Pod Fiber (BNPF) Biocomposites". W Characterization of Minerals, Metals, and Materials 2015, 637–44. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2015. http://dx.doi.org/10.1002/9781119093404.ch80.
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Campos, Rejane D., Maria Sotenko, Mahesh Hosur, Shaik Jeelani, Francisco R. V. Díaz, Esperidiana A. B. Moura, Kerry Kirwan i Emilia S. M. Seo. "Effect of Mercerization and Electron-Beam Irradiation on Mechanical Properties of High Density Polyethylene (HDPE) / Brazil Nut Pod Fiber (BNPF) Bio-Composites". W Characterization of Minerals, Metals, and Materials 2015, 637–44. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-48191-3_80.
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"Mercerization". W Encyclopedic Dictionary of Polymers, 604–5. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-30160-0_7197.
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"Slack mercerization". W Encyclopedic Dictionary of Polymers, 892. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-30160-0_10534.
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"Chapter 9 Mercerization". W Chemical Techonology in the Pre-treatment Processes of Textiles, 279–319. Elsevier, 1999. http://dx.doi.org/10.1016/s0920-4083(99)80010-3.
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Yang, J., C. Park, D. Lee i S. Kim. "Recovery of Caustic Soda in Textile Mercerization by Combined Membrane Filtration". W 2007 Cleantech Conference and Trade Show Cleantech 2007, 99–102. CRC Press, 2019. http://dx.doi.org/10.1201/9780429187469-26.
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Dash, C., A. Das, S. Behera i D. K. Bisoyi. "Mercerization effect on bio-waste eggshell reinforced polymer composite for energy saving application". W ADVANCES IN BASIC SCIENCE (ICABS 2019). AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5122394.
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Imohiosen, Odion Uvo-Oise, i Sarah Abidemi Akintola. "Effect of Sodium Carboxymethyl Cellulose from Delonix regia Sawdust on Rheological and Filtration Properties of Water Based Drilling Fluid". W SPE Nigeria Annual International Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/207200-ms.
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Abstract Over the past years, there has been an increase in the importation of Sodium Carboxymethyl cellulose (CMC), an important drilling mud polymer additive, in the Nigerian oil and gas industry. However, the ripple effects of the importation of this polymer and other oilfield chemicals on the Nigeria oil and gas industry includes rising cost of oil and gas field development, limited oil and gas industry growth, and capital flight. In order to mitigate this trend, studies on the use of local substitutes such as starch and its derivatives have gathered momentum with risk such as competition with food supply and increase in food cost. The use of sawdust wastes which offers a non-competing and a cheap source of feedstock in the production of CMC have rarely been investigated. The study therefore investigated production of CMC from sawdust waste of a highly underutilized wood (Delonix regia), after which drilling mud tests were conducted to determine the rheological and filtration properties of mud treated with the CMC products. The CMC production adopted the Williamson ether synthesis process in a slurry medium involving two main reactions of mercerization and etherification. All reaction parameters were held constant except the etherifying agent concentration. The CMC products were characterized using FTIR Spectroscopy. The synthesized carboxymethyl cellulose products yielded good filtration and rheological properties suitable for drilling fluid applications. The use of low concentrations of about 0.5g to 1.0g of the synthesized products per laboratory barrel of mud could reduce filtration volume by 11.4% to 32.9% at low temperature and pressure conditions. The synthesized CMC products obtained from this work can be used as local substitute of low viscosity foreign CMC products.