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WANG Shufang Song Cunjiang Chen Guangxin LIU Jing YANG Chao Zhang Xihui GUO Tianying Zhang Banghua 《反应性高分子(英文版)》2004,13(1):65-73
Poly (3-lydroxybutyrate-co-3-hydroxyvalerate)/Organophilic montmorillonite(PHBV/OMMT) nanocomposites were prepared and the biodegradability of the PHBV/OMMT nanocomposites was studied by a cultivation degrading method in soil suspension The relationship between structure and biodegradability of PHBV/OMMT nanocomposites was investigated. The results showed that the biodegradability of PHBV/OMMT nanocomposites decreased with increasing amount of OMMT and it was related to the number of PHBV degrading microorganisms in degradation environment, the anti-microbial property of OMMT and the degree of crystallinity of the nanocomposites. 相似文献
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Organophilic montmorillonite (OMMT) was synthesized by cationic exchange between Na-MMT and tricetadecylmethyl ammonium bromide in an aqueous solution. A new nanocomposite consisting of poly(butyl acrylate)-modified chitosan and OMMT was prepared by γ-ray irradiation polymerization in acetic acid aqueous solution. The degree of dispersion and the intercalation spacing of these nanocomposites were investigated using X-ray diffraction. The enhanced thermal stabilities of nanocomposites were characterized by the thermal gravimetric analysis. The improved mechanical properties of nanocomposites were characterized by static tensile studies and dynamic mechanical analysis. The nanocomposites showed improved resistance to water absorption. 相似文献
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A novel nanocomposite was prepared from ethylene-co-vinyl acetate copolymer (EVA) and poly-3-hydroxy butyrate-co-valerate (PHBV) in combination with small amounts of [60]Fullerene (C60). The thermal degradation as well as the incorporation effect of C60 on the thermo-oxidative decomposition of EVA/PHBV/C60 nanocomposites was investigated using thermogravimetric analysis (TGA). In order to assess the level of stabilization of nanocomposites, the oxidation induction time test was also determined. The obtained results indicated that the dispersion of C60 even at low loading (0.3, 0.5 and 0.7 wt.%) exerts a significant increase on the thermal stability properties of nanocomposite. The oxidation induction time values of nanocomposites were remarkably increased with the increase of C60 amounts. Surprisingly, the oxidation induction time of EVA/PHBV/C60 (0.3 wt.%) is 1643 s higher than that of unfilled EVA/PHBV blend.The flammability properties investigated in pyrolysis combustion flow calorimetry (PCFC) showed that the addition of C60 could prolong the time to peak of Heat Release Rate (pHRR) of around 30 °C compared to EVA/PHBV blend. It was demonstrated that C60 is inhibitor of the thermal and thermo-oxidative degradation of EVA/PHBV blend. 相似文献
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In this study, the solid-state shear pan-milling was employed to prepare a series of polymer/layered silicate (PLS) nanocomposites.
During the process of pan-milling at ambient temperature, poly(vinyl alcohol)/organic montmorillonite (PVA/OMMT) can be effectively
pulverized, resulting in coexistence of intercalated and exfoliated OMMT layers. The obtained PLS nanocomposites were characterized
by X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM analysis indicated that OMMT dispersed homogeneously
in PVA matrix and XRD results illustrated that pan-milling had an obvious effect on increase in the interlayer spacing of
OMMT, and resulted in coexistence of intercalated and exfoliated OMMT layers formed. Thermal gravimetric analysis showed that
thermal stability of PVA was improved owing to the incorporation of OMMT. Thermal decomposition kinetics of PVA/OMMT nanocomposites
with different milling cycles of OMMT was also studied. Two types of OMMT are chosen to compare the effect of hydrophilicity
of OMMT on PVA/OMMT nanocomposites. 相似文献
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The poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV)/montmorillonite(MMT) nanocomposites were investigated by wide‐angle X‐ray scattering (WAXS). The aim of the investigation was solution intercalation of MMT with PHBV. Beside the usual orthorhombic unit cell, a stable pseudohexagonal β‐structure of PHBV was obtained. Well known β‐structure has one common WAXS reflection (d = 0.480 nm), which corresponds to the mean distance of PHBV chains in the pseudohexagonal structure. The new β‐structure has two diffraction peaks in the WAXS pattern. It is a three‐dimensionally ordered crystalline structure oriented in parallel with the silica layers of MMT. The new polymorphic form is supposed to be growing on the layers of MMT. Its layers serve as primary nucleation centers for epitaxial growth of the β‐structure. After annealing, this polymorphic form of PHBV disappears and it is transformed into the more stable α‐form leading to an enhanced total crystallinity of the polymer comprised in the nanocomposite. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 751–755, 2009 相似文献
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The effects of soybean oil (SO) and epoxidized soybean oil(ESO) as biodegradable plasticizers for poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were studied using thermal and mechanical analyses. PHBV/SO and PHBV/ESO blends were prepared by evaporating solvent from blend solutions. The levels of additive in the blend varied from 5% to 30%. As a plasticizer for PHBV, ESO was more effective than SO in depression of the glass transition temperature as well as in increasing the elongation at break and the impact strength of the films with increasing levels of additive. Biodegradation of the plasticized PHBV films was carried out by accelerated compost method. The degradation rates of the blend films with SO or ESO were found to be faster than that of PHBV film. From the thermogravimetric analysis, it was found that the thermal reaction between the epoxide groups of ESO and PHBV fragments with carboxylic chain ends, occurred during the degradation of PHBV/ESO blends. 相似文献
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Biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/graphene nanosheet (GNS) composites were prepared via a solution-casting method at low GNS loadings in this work. Transmission electron microscopy revealed that a fine dispersion of GNSs was achieved in the PHBV matrix. The thermal properties of the nanocomposites were investigated by thermogravimetric analysis, and the results showed that the thermal stability of PHBV was significantly improved with a very low loading of GNSs. Nonisothermal melts crystallization behavior, spherulitic morphology and crystal structure of neat PHBV and the PHBV/GNSs nanocomposites were investigated, and the experimental results indicated that crystallization behavior of PHBV was enhanced by the presence of GNSs due to the heterogeneous nucleation effect; however, the two-dimensional (2D) GNSs might restrict the mobility of the PHBV chains in the process of crystal growing. Dynamic mechanical analysis studies showed that the storage modulus of the PHBV/GNSs nanocomposites was greatly improved. 相似文献
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PROPERTIES AND MORPHOLOGY OF UNSATURATED POLYESTER/ACRYLATE-TERMINATED POLYURETHANE/ORGANOMONTMORILLONITE NANOCOMPOSITES 总被引:1,自引:0,他引:1
Unsaturated polyester resin (UPR)/acrylate-terminated polyurethane (ATPU)/organo-modified montmorillonite (OMMT) nanocomposites were prepared by the in situ intercalative polymerization method. Samples were prepared by the sequential mixing, i.e. mixture of the ATPU and styrene (S) and OMMT were prepared in the first step; UPR was then added to the pre-intercalates of ATPU/S/OMMT. Results indicate that the mechanical properties and thermal properties of UPR/ATPU/OMMT nanocomposites greatly depend on the amount of ATPU and OMMT. Results show that the addition of ATPU could increase the impact strength of UPR/ATPU composites, but the tensile strength, flexural strength and heat resistance of the materials are obviously decreased. When the weight ratio between UPR, ATPU and OMMT were 82:15:3, the impact strength and heat distortion-temperature of nanocomposite were greatly improved, meanwhile there was little change for other properties of the nanocomposites. The synergistic enhancement effects of ATPU and OMMT on the composites were observed. The structures and morphology of the composites were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. 相似文献
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Two master-batches,polyamide 66 (PA66)/organo-montmorillonite (OMMT) and polyamide 6 (PA6)/OMMT, prepared by melt compounding with methyl methacrylate (MMA) as co-intercalation agent,have been used to prepare nearly exfoliated PA661montmorillonite (MMT) nanocomposites.The resulting nanocomposites are compared in view of their morphology and properties.Nano-scale dispersion of OMMT is realized in both types of nanocomposites,as revealed by XRD,TEM and Molau tests.PA66/MMT nanocomposites having superior me... 相似文献
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A model experiment was done to clear the formation mechanism of protective layers during combustion of polypropylene(PP)/organically modified montmorillonite(OMMT) nanocomposites.The investigation was focused on the effects of annealing temperature on the structural changes and protective layer formation.The decomposition of OMMT and degradation of PP/OMMT nanocomposites were characterized by means of thermogravimetric analysis(TGA).The structural evolution and composition change in the surface region of... 相似文献
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通过原位聚合法制备了本质阻燃聚苯乙烯[P(St-co-AEPPA)]/有机改性蒙脱土(OMMT)纳米复合物[P(St-co-AEPPA)/OMMT], 并用普通聚苯乙烯/有机改性蒙脱土(PS/OMMT)复合物作为对比实验, 研究了含磷、氮单体丙烯酸羟乙基-苯氧基-二乙基磷酰胺(AEPPA)和OMMT等添加物对本质阻燃聚苯乙烯性能的影响.用X射线衍射仪(XRD)和透射电子显微镜(TEM)分析了复合材料的结构与形貌, 并对OMMT在基体中的分散机理进行了讨论.用差示扫描量热仪(DSC)、热重分析(TGA)和微型量热仪(MCC)研究了材料的热性能和燃烧性能.结果表明, AEPPA和OMMT能够显著提高基体的热稳定性和阻燃性. 相似文献
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Preparation and characterization of poly(propylene carbonate)/montmorillonite nanocomposites by solution intercalation 总被引:4,自引:0,他引:4
Poly(propylene carbonate) (PPC) is a new biodegradable aliphatic polycarbonate. However, the poor thermal stability and low glass transition temperatures (Tg) have limited its applications. To improve the thermal properties of PPC, organophilic montmorillonite (OMMT) was mixed with PPC by a solution intercalation method to produce nanocomposites. An intercalated-and-flocculated structure of PPC/OMMT nanocomposites was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The thermal and mechanical properties of PPC/OMMT nanocomposites were investigated by thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC), and electronic tensile tester. Due to the nanometer-sized dispersion of layered silicate in polymer matrix, PPC/OMMT nanocomposites exhibit improved thermal and mechanical properties than pure PPC. When the OMMT content is 4 wt%, the PPC/OMMT nanocomposite shows the best thermal and mechanical properties. These results indicate that nanocomposition is an efficient and convenient method to improve the properties of PPC. 相似文献
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原位插层聚合制备聚丁二烯/蒙脱土纳米复合材料及其结构与性能研究 总被引:2,自引:0,他引:2
采用负离子引发原位插层聚合法制备了聚丁二烯(PB)/有机蒙脱土(OMMT)纳米复合材料(NC).对OMMT纯化方法、OMMT种类和溶剂等因素对聚合反应的影响进行了研究.不同方法纯化的OMMT消耗的BuLi量相差一倍;采用OMMT-DK1制备的NC具有较宽的分子量分布,而采用OMMT-DK1B和OMMT-DK4制备的NC则具有较窄的分子量分布;OMMT在环己烷中不溶解,在甲苯和二甲苯等溶剂中可形成均匀溶液.采用XRD、TEM和H-NMR等仪器对PB/OMMT NC的插层结构、化学结构和形态进行了分析;采用DSC、TGA和DMA等仪器对PB/OMMT NC的Tg、热学性能和动态力学性能进行了研究,结果表明,采用负离子原位插层聚合可得到剥离型PB/OMMT纳米复合材料;与OMMT插层复合明显改变了PB的微观结构组成,在OMMT含量为6.2wt%时,1,2-结构含量增加了近一倍,Tg和Tdc分别增加了10 K和16 K;E′、E″均明显提高,而tanδ下降. 相似文献
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Yong He Naoki Asakawa Yoshio Inoue 《Journal of Polymer Science.Polymer Physics》2000,38(22):2891-2900
The specific interaction between poly(3‐hydroxybutyrate) [P(3HB)] and 4,4′‐thiodiphenol (TDP) and between poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV) and TDP was investigated by Fourier transform infrared (FTIR) spectroscopy. Interassociated hydrogen bonds were found between the polyester chains and the TDP molecules in the binary blends. The fractions of associated carbonyl groups, Fb 's, in the blends first increased and then decreased as the TDP content increased. The thermal and dynamic mechanical properties of P(3HB)–TDP and PHBV–TDP blends were investigated by differential scanning calorimetry and dynamic mechanical thermal analysis, respectively. Thermal analysis revealed that the P(3HB)–TDP blends possessed eutectic phase behavior. Furthermore, it was found that the thermal and dynamic mechanical properties of P(3HB) and PHBV were greatly modified through blending with TDP. Environmental degradability in river water was evaluated by a biochemical oxygen demand tester, and it was clarified that TDP lowered the degradation rate of P(3HB). The results suggest that TDP is effective in modifying the physical properties as well as the biodegradability of polyesters. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2891–2900, 2000 相似文献
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Poly(lactic acid)/organo-montmorillonite nanocomposites were prepared by melt intercalation technique. Maleic anhydride-grafted
ethylene propylene rubber (EPMgMA) was added into the PLA/OMMT in order to improve the compatibility and toughness of the
nanocomposites. The samples were prepared by single screw extrusion followed by compression molding. The effect of OMMT and
EPMgMA on the thermal properties of PLA was studied. The thermal properties of the PLA/OMMT nanocomposites have been investigated
by using differential scanning calorimeter (DSC) and thermo-gravimetry analyzer (TG). The melting temperature (T
m), glass transition temperature (T
g), crystallization temperature (T
c), degree of crystallinity (χc), and thermal stability of the PLA/OMMT nanocomposites have been studied. It was found that the thermal properties of PLA
were greatly influenced by the addition of OMMT and EPMgMA. 相似文献
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Hai‐ming Chen Jie Chen Li‐na Shao Jing‐hui Yang Ting Huang Nan Zhang Yong Wang 《Journal of Polymer Science.Polymer Physics》2013,51(3):183-196
Organic montmorillonite (OMMT) and the one‐dimensional functionalized multiwalled carbon nanotubes (FMWCNTs) were introduced into poly(L ‐lactide) (PLLA) to prepare PLLA/OMMT and PLLA/FMWCNT nanocomposites, respectively. The effects of nanofillers on melt crystallization and cold crystallization of PLLA were comparatively investigated by using polarized optical microcopy, differential scanning calorimetry and wide angle X‐ray diffraction. The results show that FMWCNTs exhibit higher nucleation efficiency for the melt crystallization of PLLA, whereas OMMT is the better one for the cold crystallization of PLLA. Rheological properties show that both OMMT and FMWCNTs at relatively higher concentrations can form the percolated network structure in the PLLA matrix, however, the latter nanocomposites exhibit relatively denser or more compact percolated networks. The difference of the networks between OMMT and FMWCNTs is suggested to be the main reason for the different cold crystallization behaviors observed in the PLLA/OMMT and PLLA/FMWCNT nanocomposites. The dynamic mechanical analysis measurements show that OMMT is the better one to improve the stiffness of the nanocomposites in the present work. The thermogravimetric analysis measurements show that FMWCNTs have higher efficiency in improving the thermal stability of PLLA compared with OMMT. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013 相似文献