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Nouvelles stratégies d'hydrophobation de matériaux à base d'amidon plastifiéBélard, Laurent Averous, Luc. January 2007 (has links) (PDF)
Reproduction de : Thèse doctorat : Chimie des matériaux : Reims : 2007. / Titre provenant de l'écran titre. Bibliogr. p. 174-188.
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Synthesis and characterization of poly ε-caprolactone on functionalised silica substratesKhan, Javaid Hasan January 2008 (has links)
Aliphatic polyesters prepared by the ring opening polymerization of lactones and lactides, are versatile polymers having good hydrolyzability, mechanical properties and biocompatibility. These characteristics make them a leading material in biomedical and pharmaceutical industries as a resorbable implant and a vehicle for controlled drug delivery. An extensive research effort has been made to develop new initiators, catalysts for the ring opening polymerization of cyclic esters. Many effective initiators based on alkali metals, metal oxides have been developed for anionic polymerization of lactones. The main objectives of this project were to develop a novel catalyst by utilizing fully biocompatible and non-toxic reagents for the synthesis of polycaprolactone (PCL) by ring opening polymerization of cyclic esters at reasonably low temperature and a synthesis of hybrid silica nano-composite for biomedical applications and its characterization. Silica and dry calcium hydride reagents were used to successfully prepare heterogeneous catalysts for the ring opening polymerization of cyclic ester monomer å-caprolactone at reasonably low temperature of 100 oC. Two kinds of catalyst were prepared with non-functionalized and silane functionalized silica. The GP silane functionalized silica catalyst showed higher activity and higher product yield as compared to non-functionalized catalyst during polymerization at the same temperature. The in-situ polymerization kinetics of both reactions was studied using Raman spectroscopy. A silica based nano-composite was also synthesized which has a potential application in bone tissue engineering and possible drug delivery. The synthesized polyester and hybrid silica nano-composite were characterized with different analytical techniques to confirm required product formation.
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Bioresorbovatelné polyuretany s říditelnými mechanickými vlastnostmi / Bioresorbable polyurethanes with controlled mechanical propertiesLetavaj, Emil January 2017 (has links)
Presented diploma thesis deals with preparation of bioresorbable polyurethanes (PUR) and their characterization. The theoretical part describes the feedstocks used for the PUR preparation and summarizes the knowledge about PUR used in medical applications. Experimental part presents characterization of bioresorbable PUR films prepared by reactive casting in one step without the use of organic solvents. The absence of solvents represents a great advantage due to their toxicity and subsequent removal from the resulting product. The synthesis of PUR was conducted under an inert atmosphere by polyaddition reaction of hydrophobic poly(e-caprolactone) (PCL) and hydrophilic poly(ethylene glycol) (PEG) with hexamethylene diisocyanate (HDI). Synthesis under an inert atmosphere was necessary due to a side reaction of isocyanate with atmospheric humidity, which causes the formation of porous films instead of continuous ones. Prepared PUR films were characterized for different PCL/PEG ratios and different isocyanate index (ratio of NCO/OH reacted groups). PUR (isocyanate index 1.05) with PCL content 90 wt. % and higher demonstrated tought behavior in mechanical tests. Increase of isocyanate index and decrease of PCL content under 90 wt. % caused fragile sample behavior. The reason of such behavior was the different ability of PCL to crystallize in the structure of the polyurethane network. Increasing the PEG content has improved the ability of PUR films to absorb water and enhanced the rate of hydrolytic degradation. By adjusting the PCL/PEG ratio and the amount of isocyanate, solvent free bioresorbable PUR with suitable mechanical (flexibility, toughness) and physical properties (swelling, degradation) can be obtained. Prepared PUR films could be used in biomedicine e.g. as vascular grafts.
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Influência da adição de surfactantes em fibras altamente alinhadas de poli (caprolactona) obtidas por eletrofiação / Influence of surfactants addition on the fibers highly aligned of poly (e-caprolactone) produced by electrospinningSegundo, João de Deus Pereira de Moraes, 1988- 28 August 2018 (has links)
Orientador: Marcos Akira D'Ávila / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-28T14:33:17Z (GMT). No. of bitstreams: 1
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Previous issue date: 2015 / Resumo: A eletrofiação é uma das principais técnicas para produzir fibras poliméricas ultrafinas na escala nano e submicrométrica. A poli ('épsilon'-caprolactona) (PCL) é um polímero sintético biodegradável bastante utilizado na área médica. Fibras de PCL obtidas por eletrofiação formam mantas porosas propícias para aplicações biomédicas como na engenharia tecidual. Em algumas aplicações as fibras alinhadas de PCL são de interesse, pois conferem melhorias em determinadas propriedades quando comparadas com fibras aleatórias. A PCL é considerada um polímero moderadamente hidrofóbico e a eletrofiação aumenta a hidrofobicidade das mantas. Os surfactantes têm a capacidade de modificar a superfície das fibras poliméricas aumentando a sua molhabilidade. Este trabalho versa sobre a influência da adição de surfactantes catiônico (CTAB), aniônico (SDS) e não-iônico (Triton X-100) na morfologia e no alto alinhamento de fibras de PCL obtidas por eletrofiação com coletor rotativo. Preparou-se solução de PCL contendo clorofórmio e acetona como solventes. As concentrações em massa de surfactantes utilizadas foram: 0,05; 0,1; 0,5; 1,0 e 1,5 wt%. As soluções foram caracterizadas através de medições de tensão superficial, condutividade elétrica e reologia. As morfologias das fibras foram analisadas com Microscópio Eletrônico de Varredura (MEV) juntamente com o software imageJ e o plugin OrientationJ. As fibras foram caracterizadas quanto às propriedades térmicas (DSC), análise química (FTIR) e molhabilidade (ângulo de contato). Através dos resultados obtidos, observou-se que a condutividade elétrica das soluções foi aumentada de acordo com o tipo de surfactante. A reologia foi alterada com os tipos e as concentrações, enquanto a tensão superficial não apresentou mudança significativa com a adição dos surfactantes. Os surfactantes CTAB e SDS alteraram o alinhamento das fibras de PCL e, dependendo da concentração, melhoraram a uniformidade dos diâmetros das fibras. Os surfactantes foram capazes de melhorar a molhabilidade das mantas, enquanto as propriedades térmicas foram mantidas / Abstract: The electrospinning is one of the main techniques to produce ultrafine polymeric fibers in the nano and submicron scale. Poly ('épsilon'-caprolactone) (PCL) is a biodegradable synthetic polymer widely used in the medical field. Electrospun PCL fibers form porous mats favorable for biomedical applications such as in tissue engineering. PCL aligned fibers are of interest since it expand the applications of these fibers and confer improvements in certain properties when compared with random fibers. PCL considered a moderately hydrophobic polymer and the electrospinning increases the hydrophobicity of the mats. Surfactants have the ability to modify the surface of polymeric fibers increasing its wettability. This work is concerned with the study of the effects of adding cationic (CTAB), anionic (SDS) and nonionic (Triton X-100) surfactants in the morphology and alignment PCL fibers obtained by electrospinning used a rotating collector. Poly ('épsilon'-caprolactone) (PCL) solutions with chloroform and acetone as solvent were prepared and different concentrations of surfactants were used: 0.05; 0.1; 0.5; 1.0; and 1,5 wt% in mass. Solutions characterized by measurements of surface tension, electric conductivity and viscosity. The morphology of the fibers analyzed by Scanning Electron Microscopy (SEM) together with the ImageJ software and OrientationJ plugin. The fibers characterized by differential scanning calorimetry (DSC), infrared spectroscopy (FTIR) and wettability (contact angle). Through the results obtained, the electrical conductivity of the solutions increased according to the type of surfactant. The rheology changed with the types and concentrations, while the surface tension did not change significantly with the addition of surfactants. The presence of surfactants CTAB and SDS influence the alignment of the PCL fibers, and depending on the concentration, improve the uniformity of fiber diameters. The surfactants were able to improve the wettability of mats, while the thermal properties maintained / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica
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Biosynthetic PCL-graft-collagen bulk material for tissue engineering applicationsGentile, P., McColgan-Bannon, K., Gianone, N.C., Sefat, Farshid, Dalgarno, K., Ferreira, A.M. 23 June 2017 (has links)
Yes / Biosynthetic materials have emerged as one of the most exciting and productive fields in polymer chemistry due to their widespread adoption and potential applications in tissue engineering (TE) research. In this work, we report the synthesis of a poly(ε-caprolactone)-graft-collagen (PCL-g-Coll) copolymer. We combine its good mechanical and biodegradable PCL properties with the great biological properties of type I collagen as a functional material for TE. PCL, previously dissolved in dimethylformamide/dichloromethane mixture, and reacted with collagen using carbodiimide coupling chemistry. The synthesised material was characterised physically, chemically and biologically, using pure PCL and PCL/Coll blend samples as control. Infrared spectroscopy evidenced the presence of amide I and II peaks for the conjugated material. Similarly, XPS evidenced the presence of C–N and N–C=O bonds (8.96 ± 2.02% and 8.52 ± 0.63%; respectively) for PCL-g-Coll. Static contact angles showed a slight decrease in the conjugated sample. However, good biocompatibility and metabolic activity was obtained on PCL-g-Coll films compared to PCL and blend controls. After 3 days of culture, fibroblasts exhibited a spindle-like morphology, spreading homogeneously along the PCL-g-Coll film surface. We have engineered a functional biosynthetic polymer that can be processed by electrospinning. / The EPSRC Centre in Innovative Manufacturing in Medical Devices (MeDe Innovation; EP/K029592/1).
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Preparation and properties of bio-based polyurethane made from natural rubber and poly(ε-caprolactone) / Synthèse et étude des propriétés d’un polyuréthane biosourcé obtenu du caoutchouc naturel et du poly(ε-caprolactone)Panwiriyarat, Wannarat 18 December 2012 (has links)
L’objectif de ce travail de thèse était la synthèse d’un nouveau matériau polyuréthane biorsourcé composé par du caoutchouc naturel modifié chimiquement et par du poly(ε-caprolactone), (PCL), en présence ou absence d’isocyanates. Des oligoisoprènes téléchéliques hydroxylés (HTNR) ont été obtenus après époxidation du caoutchouc naturel et réduction des oligomères carbonyles. Plusieurs paramètres ont été étudiés comme la nature et la quantité relative de diisocyanate, le rapport molaire entre diisocyanate et diol (NCO:OH), l’influence de la masse molaire des diols HTNR et PCL, le pourcentage de 1,4-butane diol (BDO, extenseur de chaîne), et le rapport molaire entre les diols HTNR:PCL. Trois types de diisocyanate ont été employés : isophorone diisocyanate (IPDI), toluène-2,4-diisocyanate (TDI) et hexaméthylène diisocyanate (HDI). Masses molaires différentes ont été utilisées pour les diols HTNR et PCL: 1700, 2800 et 2900 g/mol pour HTNR et 530 et 2000 g/mol pour PCL. Le rapport molaire entre NCO:OH était entre 0,75:1,00 – 2,85:1,00. Les PU ont été préparés par la méthode « one shot » et les structures chimiques des HTNR et PU ont été identifiées par 1H-NMR et FTIR. La résistance à la traction et à la rupture ont été étudiées. La caractérisation a été conduite par DSC, DMTA, ATG et spectroscopie Raman. Une étude préliminaire a montré que la masse molaire du PU augmentait avec le rapport NCO:OH et le temps de réaction, et que le chloroforme n’était pas un bon solvant pour obtenir des films. Le tetrahydrofurane était le solvant le plus approprié et il a été utilisé par la suite pour toutes les polymérisations. Le rapport NCO:OH = 1,25:1,00 s’est révélé optimal pour obtenir des films. L’analyse FTIR a permis de vérifier la présence de liaisons uréthane, de points de réticulation et de branchements. Le polyuréthane a montré des propriétés mécaniques excellentes dépendantes de la composition chimique. Si on exclue l’utilisation de PCL2000 et de HDI, le comportement à la traction était caractéristique des élastomères. Les PU étaient amorphes sauf lorsque le HDI a été employé. Duos ce cos été obtenais un PU semi cristallin. Cette cristallinité augmente le module de Young, la résistance à la rupture, la dureté et la stabilité thermique du PU. Pour ce PU ont observé une séparation de phase entre les segments du PCL et du HTNR. Les chaînes plus longues et plus flexibles du HTNR et leur non polarité sont responsables de la diminution des propriétés mécaniques et des températures de transition. Le materiae pane d’un comportement élastomère a un comportement plastique pour un rapport NCO:OH élevé (2,85 :1,00). Le dégréé de réticulation élevé a été retenu comme la cause pour laquelle il n’y avait pas de séparation de phase entre les segments souples et durs. La liaison hydrogène entre le diol PCL et le segment hard a généré des Tg élevées. Les spectres Raman ont montré la formation de la liaison uréthane du PU contenant différents diisocyanates. La synthèse de PU sans diisocyanate a été obtenue grâce à une réaction de polyaddition entre des carbonates cycliques téléchéliques dérivés du PCL et du caoutchouc naturel, et la 1,4-butylène diamine. Les structures contenant des carbonates cycliques ont été obtenues grâce à la modification des groupes OH sur le HTNR et le PCL à groupes carboxyle, utilisant l’anhydride succinique, et a la réaction successive avec le glycérol carbonate. / The aim of this research work was to prepare a novel bio-based polyurethane (PU) composed by chemically modified natural rubber (NR) and poly(ε-caprolactone) diol (PCL), with and without isocyanate. Hydroxyl telechelic natural rubber (HTNR) was synthesized via epoxidized and carbonyl telechelic natural rubber. The parameters studied included type and relative amount of diisocyanate, molar ratio between diisocyante and diol (NCO:OH), molecular weight of HTNR and PCL diol, 1,4-butane diol (BDO, chain extender) content and molar ratio between HTNR:PCL diols. Three types of diisocyanate were employed: isophorone diisocyanate (IPDI), toluene-2,4-diisocyanate (TDI) and hexamethylene diisocyanate (HDI). The number average molecular weights of HTNR and PCL diol were selected: 1700, 2800 and 2900 g/mol for HTNR and 530 and 2000 g/mol for PCL diol. The NCO:OH molar ratio was in the range 0.75:1.00 – 2.85:1.00. PU was prepared by one-shot method. The chemical structure of HTNR, PCL and PU were identified by 1H-NMR FTIR and Raman spectroscopy. Tensile properties and tear resistance of PU were investigated. Characterization of mechanical and thermal properties was carried out using DSC, DMTA and TGA. A preliminary study showed that the molecular weight of PU increased with increasing NCO:OH molar ratio and reaction time, and chloroform was not a good solvent for polymer casting. Tetrahydrofuran was an appropriate solvent as it allowed film formation and it was used in all the other experiments. The NCO:OH molar ratio of 1.25:1.00 was suitable for preparing good PU films. FTIR analysis verified the presence of urethane linkages and crosslinking or chain branching. PU demonstrated excellent mechanical properties, which depended on the chemical composition. Excluding the use of PCL2000 and HDI, the tensile behavior seemed to have typical elastomeric characteristics. PU became amorphous except in the case of HDI, which was able to crystallize leading to the crystalline PU. The crystallinity increased the Young’s modulus, the tear strength, the hardness and the thermal stability of PU. PU showed a phase separation between the PCL and HTNR segments. The longer and more flexible chain and non-polarity of HTNR were responsible of a decrease of the mechanical properties and transition temperatures. The very high molar ratio of NCO:OH (2.85:1.00) changed the tensile characteristics from an elastomer to a plastic. The high crosslinking was attributed to there being no phase separation between the hard and the soft segment. Hydrogen bonding between the PCL diol and the hard segment produced a high Tg. Raman spectra were able to identify the urethane linkage of PU containing different diisocyanates by showing the relative absorbance peaks. Synthesis of PU without isocyanate was successfully obtained via a polyaddition polymerization between a cyclic carbonate telechelic PCL/NR and 1,4-butylenediamine. The cyclic carbonate telechelic NR and cyclic carbonate telechelic PCL were prepared via the modification of the hydroxyl end groups of HTNR and PCL diols to carboxylic acid end groups by reacting with succinic anhydride. Then, the carboxylic acid end groups were changed to the cyclic carbonate end groups by using glycerol carbonate.
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Preparation of polymeric nanoparticles for topical anti-inflammatory applications / Préparation de nanoparticules à base de polymère pour applications anti-inflammatoires topiquesBadri, Waisudin 19 June 2018 (has links)
L'objectif de cette thèse est d’encapsuler l'indométacine dans des nanoparticules polymériques en association à l’huile essentielle de Nigella Sativa L. extraite à partir de ses graines afin d’optimiser son utilisation par voie cutanée et potentialiser son activité anti-inflammatoire.Pour ce faire, des nanoparticules à base de poly-epsilon-caprolactone ont été préparées par nanoprécipitation. Une étude systématique a été menée pour comprendre l'effet de la variation des paramètres de préparation sur les propriétés colloïdales des nanoparticules obtenues. Une fois les différents paramètres optimisés, l'indométacine et l'huile essentielle de Nigella Sativa L. ont été encapsulées séparément dans les nanoparticules polymériques. Puis, l’ensemble, indométacine et huile essentielle de Nigella Sativa L. a été encapsulé. Les nanoparticules préparées ont à chaque fois été caractérisées notamment en termes de stabilité et de performance d’encapsulation. Ensuite, nous avons mené une étude ex vivo et in vivo des nanoparticules obtenues afin d’évaluer le potentiel de pénétration cutanée d’une part, et le potentiel clinique dans la prise en charge de l’inflammation / The objective of this PhD thesis was to extract the Nigella Sativa L. Seeds Essential Oil and its encapsulation together with indomethacin within polymeric nanoparticles in order to reduce taken amount and to enhance indomethacin cutaneous penetration, and anti-inflammatory activity. To this direction poly-epsilon-caprolactone based nanoparticles were designed using nanoprecipitation method. A systematic study was performed to figure out the effect of process and formulation parameters on the characteristics of obtained nanoparticles. Once the effects of all parameters were studied, then indomethacin and Nigella Sativa L. Seeds Essential Oil was encapsulated separately. Consequently, both together indomethacin and Nigella Sativa L. Seeds Essential Oil was encapsulated. Then prepared nanoparticles were characterized in terms of stability, encapsulation efficiency. In addition, ex vivo skin penetration and in vivo anti-inflammatory activity of designed nanoparticles was investigated
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Crystallization in Constrained Polymer Structures : Approaching the Unsolved Problems in Polymer CrystallizationNúñez, Eugenia January 2006 (has links)
The knowledge regarding certain issues in polymer crystallization e.g. the possible existence of short–lived mesophases remains inconclusive due to experimental limitations. Polymers undergo chain folding upon crystallization, which introduces some complications that are not found in crystallization of low molar mass materials. Chain–folded crystals are far from their equilibrium shape and they rearrange rapidly at the crystallization temperature. This, together with the slow experimental techniques traditionally used, impedes the observation of the originally formed structures. To approach this problem, molecularly constrained polymer structures (in which the crystallizing chains are fixed at one end whereas the other end is free to move) have been studied by X–ray diffraction, differential scanning calorimetry, polarized optical microscopy, transmission electron microscopy and atomic force microscopy. The crystallization studies performed in star–branched polyesters showed that the dendritic cores have a pronounced effect on the crystallization of the linear poly(ε–caprolactone) (PCL) arms attached to them. The star–branched polymers showed slower crystal rearrangement, higher equilibrium melting point, higher fold surface free energy, moderately lower crystallinity, and a greater tendency to form spherulites in comparison with linear PCL. The crystal unit cell was the same in both linear and star–branched PCL. Single crystals of the star–branched polymers were more irregular and showed smoother fold surfaces than linear PCL crystals. No sectorial preference was observed in the crystals of the star–branched polymers upon melting while the single crystals of linear PCL showed earlier melting in the {100} sectors than in the {110} sectors. Some of the differences observed can be attributed to the dendritic cores, which must be placed in the vicinity of the fold surface and thus influence the fold surface structure, the possibility of major crystal rearrangement and the presence of a significant cilia phase during crystal growth causing diverging crystal lamellae and consequent spherulite formation. The attachment of the many crystallizable chains to a single core reduces the melt entropy, which explains the higher equilibrium melting point of star–branched PCL. The crystallization behavior of a series of poly(ethylene oxybenzoate)s was also studied. The polymers showed a profound tendency for crystal rearrangement during melting even at high heating rates. The Hoffman–Weeks extrapolation method was found to be unsuitable to calculate the equilibrium melting point of the samples studied because the melting point vs. crystallization temperature data were sensitive to the variations in crystallisation time, which led to significant variations in the equilibrium melting points obtained. / QC 20100914
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Biodegradable Silicon-Containing Elastomers for Tissue Engineering Scaffolds and Shape Memory PolymersSchoener, Cody A. 2009 August 1900 (has links)
Commonly used thermoplastic biodegradable polymers are generally brittle and
lack appreciable elasticity at physiological temperature and thereby fail to mimic the
elastic nature of many human soft tissues such as blood vessels. Thus, there is a need for
biomaterials which exhibit elasticity. Biodegradable elastomers are promising candidates
whose elasticity more closely parallels that of soft tissues. In this research, we developed
hybrid biodegradable elastomers comprised of organic and inorganic polymer
components in a block copolymer system: poly(e-caprolactone) (PCL) and
poly(dimethylsiloxane) (PDMS), respectively. A block structure maintains the distinct
properties of the PCL and PDMS components. These elastomers may be useful for the
tissue engineering of soft tissues as well as for shape memory polymer (SMP) devices.
Tri-block macromers of the form PCLn-block-PDMSm-block-PCLn were
developed to permit systematic variations to key features including: PDMS block length,
PCL block length, PDMS:PCL ratio, and crosslink density. The macromer was capped
with acrylating groups (AcO) to permit their photochemical cure to form elastomers.
Thus, a series of biodegradable elastomers were prepared by photocrosslinking a series of macromers in which the PCL blocks varied (n = 5, 10, 20, 30, and 40) and the PDMS
block was maintained (m = 37). All elastomers displayed hydrophobic surface properties
and high thermal stability. These elastomers demonstrated systematic tuning of
mechanical properties as a function of PCL block length or crosslink density. Notable
was strains at break as high as 814% making them suitable for elastomeric
bioapplications.
Elastomers with a critical PCL block length (n = 30 or 40) exhibited shape
memory properties. Shape memory polymers based on an organic-inorganic,
photocurable silicon-containing polymer system is a first of its kind. This SMP
demonstrated strain fixity of 100% and strain recovery near 100% after the third
thermomechanical cycle. Transition from temporary to permanent shape was quite rapid
(2 sec) and at temperatures near body temperature (60 degrees C). Lastly, porous analogues of
the biodegradable elastomers were created using a novel porogen - salt leaching
technique. Resulting porous elastomers were designed for tissue engineering scaffolds or
shape memory foams.
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Obtenção de sistemas de PCL com subproduto da cultura algodoeira.BEZERRA, Elieber Barros. 02 February 2018 (has links)
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Previous issue date: 2014-08-19 / Estudos têm sido realizados com o intuito de criar processos que utilizem
matérias-primas renováveis, gerando assim produtos não agressivos ao meio
ambiente, sem perder em qualidade ou desempenho. Este trabalho teve como
objetivo a obtenção de sistemas de poli(ε-caprolactona) (PCL) com subproduto
da cultura algodoeira, a fim de avaliar a influência dos componentes línter e
nanolínter de algodão nas propriedades finais dos compósitos poliméricos. Os
sistemas de PCL com 1, 3 e 5% de cargas foram obtidos em extrusora e,
processados em injetora, caracterizados quanto à composição lignocelulósica,
tamanho de partícula e potencial zeta, difração de raios-X (DRX),
termogravimetria (TG), calorimetria exploratória diferencial (DSC), microscopia
eletrônica de varredura (MEV), propriedades mecânicas e temperatura de
deflexão térmica (HDT). Por meio da caracterização lignocelulósica foi
observado um alto teor de celulose para a fibra vegetal e, por medida do
tamanho de partícula e potencial zeta, foram observadas partículas com
diâmetro médio na faixa nanométrica. Por DRX, foi vista a presença dos picos
característicos da PCL pura, do línter e da nanocelulose. Para os sistemas
PCL/Línter e PCL/Nano não foram visualizadas alterações nos picos
característicos da matriz. Por TG, foi verificada que a presença da carga não
influenciou no comportamento térmico dos sistemas. Por DSC, não foram
observadas alterações na cristalinidade dos sistemas com a presença do línter
e do nanolínter. Por meio das fotomicrografias de MEV, foi observada a má
adesão da matriz polimérica ao línter e ao nanolínter. Por meio dos ensaios de
tração e flexão, foi observado que os sistemas com línter apresentaram um
pequeno aumento no módulo e na resistência. Para os sistemas contendo
nanolínter, os valores de módulo e de resistência foram similares aos da matriz.
Por meio do ensaio de resistência ao impacto, foi observado que as cargas
utilizadas diminuíram a resistência dos compósitos. Um aumento na
temperatura de deflexão térmica (HDT) dos sistemas foi visto com a presença
das cargas. / Estudos têm sido realizados com o intuito de criar processos que utilizem
matérias-primas renováveis, gerando assim produtos não agressivos ao meio
ambiente, sem perder em qualidade ou desempenho. Este trabalho teve como
objetivo a obtenção de sistemas de poli(ε-caprolactona) (PCL) com subproduto
da cultura algodoeira, a fim de avaliar a influência dos componentes línter e
nanolínter de algodão nas propriedades finais dos compósitos poliméricos. Os
sistemas de PCL com 1, 3 e 5% de cargas foram obtidos em extrusora e,
processados em injetora, caracterizados quanto à composição lignocelulósica,
tamanho de partícula e potencial zeta, difração de raios-X (DRX),
termogravimetria (TG), calorimetria exploratória diferencial (DSC), microscopia
eletrônica de varredura (MEV), propriedades mecânicas e temperatura de
deflexão térmica (HDT). Por meio da caracterização lignocelulósica foi
observado um alto teor de celulose para a fibra vegetal e, por medida do
tamanho de partícula e potencial zeta, foram observadas partículas com
diâmetro médio na faixa nanométrica. Por DRX, foi vista a presença dos picos
característicos da PCL pura, do línter e da nanocelulose. Para os sistemas
PCL/Línter e PCL/Nano não foram visualizadas alterações nos picos
característicos da matriz. Por TG, foi verificada que a presença da carga não
influenciou no comportamento térmico dos sistemas. Por DSC, não foram
observadas alterações na cristalinidade dos sistemas com a presença do línter
e do nanolínter. Por meio das fotomicrografias de MEV, foi observada a má
adesão da matriz polimérica ao línter e ao nanolínter. Por meio dos ensaios de
tração e flexão, foi observado que os sistemas com línter apresentaram um
pequeno aumento no módulo e na resistência. Para os sistemas contendo
nanolínter, os valores de módulo e de resistência foram similares aos da matriz.
Por meio do ensaio de resistência ao impacto, foi observado que as cargas
utilizadas diminuíram a resistência dos compósitos. Um aumento na
temperatura de deflexão térmica (HDT) dos sistemas foi visto com a presença
das cargas.
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