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以具有核壳结构的聚丙烯酸酯颗粒增韧环氧树脂胶粘剂 总被引:8,自引:2,他引:8
研制了PEA/PMMA~(…)核壳乳胶粒子,并用于改性环氧树脂。SEM照片指出PBA分散相的平均粒径尺寸。力学性能及Tg测试结果表明改性环氧树脂体系的力学性能大幅度提高,而Tg并未降低。PBA/PMMA核壳粒子为环氧树脂有效的增韧剂。 相似文献
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《合成树脂及塑料》2015,(4)
采用预乳化-半连续种子乳液聚合法制备了聚丙烯酸丁酯(PBA)-聚(甲基丙烯酸甲酯-乙酸乙烯酯)[P(MMA-VAc)]核壳乳胶粒子,然后经醇解得到表层含羟基的PBA-聚(甲基丙烯酸甲酯-乙烯醇)[P(MMAVA)]核壳乳胶粒子。采用傅里叶变换红外光谱仪、差示扫描量热仪及透射电子显微镜等表征了核壳乳胶粒子的结构和形态。结果表明:PBA-P(MMA-VAc)为核壳结构,核壳乳胶粒子的平均粒径为340 nm,其中PBA核的平均粒径为270 nm;功能单体乙酸乙烯酯(VAc)参与了壳层共聚合,并且部分P(MMA-VAc)成功接枝到PBA核上;VAc用量增加导致壳层交联度提高、玻璃化转变温度上升,当VAc用量为壳层单体质量的20%时,壳层中以化学键连接在PBA核上的乙烯醇质量分数达5.44%。 相似文献
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采用预乳化-半连续种子乳液聚合方法合成了聚丙烯酸丁酯(PBA)-聚(甲基丙烯酸甲酯-丙烯酰胺)核壳乳胶粒子,通过Hofmann降级反应成功地将其改性为表层含氨基的PBA-聚(甲基丙烯酸甲酯-乙烯胺)[P(MMA-VAm)]核壳乳胶粒子,并对其进行了测试与表征。结果表明:PBA-P(MMA-VAm)核壳乳胶粒子呈球形且分散均匀,平均粒径在340 nm左右,其中,PBA核乳胶粒子平均粒径在270 nm左右;随着丙烯酰胺(AM)用量增加,壳层共聚物P(MMA-VAm)的玻璃化转变温度逐渐降低,PBA-P(MMA-VAm)核壳乳胶粒子的热稳定性受到一定影响;随着AM用量增加,PBA-P(MMA-VAm)核壳乳胶粒子壳层氨基含量逐渐增大,当AM用量为MMA质量的20%时,氨基质量分数达到2%以上。 相似文献
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《合成树脂及塑料》2017,(1)
采用预乳化-半连续种子乳液聚合方法合成了聚丙烯酸丁酯(PBA)-聚(甲基丙烯酸甲酯-丙烯酰胺)核壳乳胶粒子,通过Hofmann降级反应成功地将其改性为表层含氨基的PBA-聚(甲基丙烯酸甲酯-乙烯胺)[P(MMA-VAm)]核壳乳胶粒子,并对其进行了测试与表征。结果表明:PBA-P(MMA-VAm)核壳乳胶粒子呈球形且分散均匀,平均粒径在340 nm左右,其中,PBA核乳胶粒子平均粒径在270 nm左右;随着丙烯酰胺(AM)用量增加,壳层共聚物P(MMA-VAm)的玻璃化转变温度逐渐降低,PBA-P(MMA-VAm)核壳乳胶粒子的热稳定性受到一定影响;随着AM用量增加,PBA-P(MMA-VAm)核壳乳胶粒子壳层氨基含量逐渐增大,当AM用量为MMA质量的20%时,氨基质量分数达到2%以上。 相似文献
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《合成树脂及塑料》2016,(2)
采用预乳化半连续种子乳液聚合方法制备了一种新型的表层含氨基的聚甲基丙烯酸丁酯(PBA)-聚(甲基丙烯酸甲酯-甲基丙烯酸二甲氨基乙酯)[P(MMA-DMA)]核壳乳胶粒子,并通过激光粒径分析仪、透射电子显微镜、X射线光电子能谱仪和元素分析仪等对其进行表征。结果表明:PBA-P(MMA-DMA)乳胶粒子为核壳结构,PBA核芯和PBA-P(MMA-DMA)核壳乳胶粒子的平均粒径分别为270,340 nm;PBA-P(MMA-DMA)核壳乳胶粒子的壳层确实含有甲基丙烯酸二甲氨基乙酯(DMA),当DMA用量为甲基丙烯酸甲酯质量的10.0%时,PBAP(MMA-DMA)核壳乳胶粒子氮元素质量分数达0.29%,折合壳层氨基质量分数达0.78%。 相似文献
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Poly(butyl acrylate)/poly(methyl methacrylate) (PBA/PMMA) core–shell particles embedded with nanometer‐sized silica particles were prepared by emulsion polymerization of butyl acrylate (BA) in the presence of silica particles preabsorbed with 2,2′‐azobis(2‐amidinopropane)dihydrochloride (AIBA) initiator and subsequent MMA emulsion polymerization in the presence of PBA/silica composite particles. The morphologies of the resulting PBA/silica and PBA/silica/PMMA composite particles were characterized, which showed that AIBA could be absorbed effectively onto silica particles when the pH of the dispersion medium was greater than the isoelectric potential point of silica. The critical amount of AIBA added to have stable dispersion of silica particles increased as the pH of the dispersion medium increased. PBA/silica composite particles prepared by in situ emulsion polymerization using silica preabsorbed with AIBA showed higher silica absorption efficiency than did the PBA/silica composite particles prepared by direct mixing of PBA latex and silica dispersion or by emulsion polymerization in which AIBA was added after the mixing of BA and silica. The PBA/silica composite particles exhibited a raspberrylike morphology, with silica particles “adhered” to the surfaces of the PBA particles, whereas the PBA/silica/PMMA composite latex particles exhibited a sandwich morphology, with silica particles mainly at the interface between the PBA core and the PMMA shell. Subsequently, the PBA/silica/PMMA composite latex obtained had a narrow particle size distribution and good dispersion stability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3425–3432, 2006 相似文献
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In this article, PBA/P(MMA–crosslinking agent)-composite particle latexes were prepared by semicontinuous seeded emulsion polymerization. To determine the seed emulsion's saturating capacity of an emulsifier, a mathematical model was built to simulate the changes of the seed PBA emulsion's surface tension with the amount of emulsifier added dropwise. The effects of the emulsifier amount added in the second stage and the addition method on the morphology of the composite particles were studied. The results were shown as follows: If the amount of emulsifier added in one batch to the seed emulsion in the second stage was less than or equal to the saturating capacity of emulsifier of the seed emulsion (Cs), the morphology of the particles was “core–shell”; otherwise, a few particles were of a core–shell structure. However, if shell materials were preemulsified and added dropwise at an appropriate rate, the latex particles were still of a core–shell structure, even when the amount of emulsifier added to the seed emulsion was greater than the Cs. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 969–975, 1998 相似文献
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Conductive polymer particles, polyaniline (PANI)‐coated poly(methyl methacrylate–butyl acrylate–acrylic acid) [P(MMA–BA–AA)] nanoparticles, were prepared. The P(MMA–BA–AA)/PANI core–shell complex particles were synthesized with a two‐step miniemulsion polymerization method with P(MMA–BA–AA) as the core and PANI as the shell. The first step was to prepare the P(MMA–BA–AA) latex particles as the core via miniemulsion polymerization and then to prepare the P(MMA–BA–AA)/PANI core–shell particles. The aniline monomer was added to the mixture of water and core nanoparticles. The aniline monomer could be attracted near the outer surface of the core particles. The polymerization of aniline was started under the action of ammonium persulfate (APS). The final product was the desired core–shell nanoparticles. The morphology of the P(MMA–BA–AA) and P(MMA–BA–AA)/PANI particles was characterized with transmission electron microscopy. The core–shell structure of the P(MMA–BA–AA)/PANI composites was further determined by Fourier transform spectroscopy and ultraviolet–visible measurements. The conductive flakes made from the core–shell latexes were prepared, and the electrical conductivities of the flakes were studied. The highest conductivity of the P(MMA–BA–AA)/PANI pellets was 2.05 S/cm. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
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Poly(butyl acrylate–methyl methacrylate) [P(BA–MMA]/polyaniline (PANI) core–shell complex particles were synthesized with a two‐step emulsion polymerization method with P(BA–MMA) as the core and PANI as the shell. The first step was to prepare P(BA–MMA) latex particles as the core via soapless emulsion polymerization. The second step was to prepare P(BA–MMA)/PANI core–shell particles. Sodium dodecyl sulfate was fed into the P(BA–MMA) emulsion as a surfactant, and this was followed by the addition of the aniline monomer. A bilayer structure of the surfactant over the surfaces of the core particles was desired so that the aniline monomer could be attracted near the outer surface of the core particles. In some cases, dodecyl benzene sulfonic acid was added after 2 h when the polymerization of aniline was started. The final product was the desired core–shell particles. The morphology of P(BA–MMA) and P(BA–MMA)/PANI particles was observed with transmission electron microscopy. The thermal properties were studied with thermogravimetric analysis and differential scanning calorimetry. Furthermore, conductive films made from the core–shell latexes were prepared, and the electrical conductivities of the films were studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 823–830, 2007 相似文献
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Prapasri Rajatapiti Victoria L. Dimonie Mohamed S. El-Aasser Menas S. Vratsanos 《应用聚合物科学杂志》1997,63(2):205-219
Graft copolymers with poly(n-butyl acrylate) (PBA) backbones and poly(methyl methacrylate) (PMMA) macromonomer side chains are used as compatibilizing agents for PBA/PMMA composite latexes. The composite latexes are prepared by seeded emulsion polymerization of methyl methacrylate (MMA) in the presence of PBA particles. Graft copolymers were already incorporated into the PBA particles prior to using these particles as seed via miniemulsion (co)polymerization of n-butyl acrylate (BA) in the presence of the macromonomers. Comparison between size averages of composite and seed particles indicates no secondary nucleation of MMA during seeded emulsion polymerization. Transmission electron microscopy (TEM) observations of composite particles show the dependence of particle morphologies with the amount of macromonomer (i.e., mole ratio of macromonomer to BA and molecular weight of macromonomer) in seed latex. The more uniform coverage with the higher amount of macromonomer suggests that graft copolymers decrease the interfacial tension between core and shell layers in the composite particles. Dynamic mechanical analysis of composite latex films indicates the existence of an interphase region between PBA and PMMA. The dynamic mechanical properties of these films are related to the morphology of the composite particles, the arrangement of phases in the films, and the volume of the interphase polymer. © 1997 John Wiley & Sons, Inc. 相似文献
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采用种子乳液聚合法制备了丙烯酸(AA)/丙烯酰胺(AM)交联的、具有核壳结构的甲基丙烯酸甲酯(MMA)/丙烯酸丁酯(BA)/丙烯腈(AN)复合乳液,研究了壳层软硬单体比、复合交联剂AA/AM及壳层交联单体AN用量对乳液胶膜拉伸强度和断裂伸长率的影响。结果表明:当核层和壳层之间的玻璃化转变温度Tg相近时,核壳乳液核、壳两部分分子链的协调运动能力较强,其乳液胶膜拉伸强度和断裂伸长率都较大;当AA/AM用量不超过4%时,乳液胶膜强度和断裂伸长率随着AA/AM用量增大而增大;随着AN用量的增加,乳液胶膜拉伸强度逐渐增大。 相似文献
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The radical-induced grafting of n-butyl acrylate (BA) onto poly(butadiene-co-styrene) [(P(Bd-S)] latexes during seeded emulsion polymerization was studied. This P(Bd-S)/PBA rubber/rubber core/shell latex system exhibited unique grafting behavior as compared to other extensively studied rubber/glass core/shell latex systems, such as poly(butadiene-co-styrene)/poly(methyl methacrylate) [P(Bd-S)/PMMA], poly(butadiene-co-styrene)/polystyrene [P(Bd-S)/PS] and poly(butadiene-co-styrene)/poly(acrylonitrile)[P(Bd-S)/PAN]. These composite latexes were characterized by the formation of a highly grafted/crosslinked P(Bd-S)/PBA interphase zone generated during the seeded emulsion polymerization process. Although both of the individual core and shell polymers studied were “soft” themselves, the resulting P(Bd-S)/PBA composite latex particles were found to be rather “hard.” The formation of the interphase zone was studied by using techniques such as solvent extraction, differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:511–523, 1997 相似文献
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Yu-Sheng Liu Chun-Hsun Chu Chen-An Tsai Yi-Hsuan Chen Chia-Fen Lee 《Polymer Bulletin》2012,69(6):699-714
In this study, the hollow latex particle was synthesized by three processes. The first process was to synthesize the poly(methyl methacrylate-co-methacrylic acid) (poly(MMA-MAA)) copolymer latex particles by the method of soapless emulsion polymerization. Following the first process, the second process was to polymerize MMA, MAA, 3,3-(trimethoxysilyl) propyl methacrylate (MPS), and ethylene glycol dimethacrylate in the presence of poly(MMA-MAA) latex particles to form the linear poly(MMA-MAA)/crosslinking poly(MMA-MAA-MPS) core–shell latex particles. In the third process, the core–shell latex particles were heated in the presence of ammonia to form the poly(MMA-MAA-MPS) hollow latex particles. A sufficient heating time and high-heating temperature were necessary for the ammonia to dissolve the linear poly(MMA-MAA) core to form a perfect hollow structure. The crosslinking poly(MMA-MAA-MPS) shell was a barrier for the ammonia to diffuse into the latex particles so that the latex particle with the high-crosslinking shell showed an imperfect hollow structure. Besides, the hollow poly(MMA-MAA-MPS) latex particles reacted with ZnO nanoparticles, which were synthesized by a traditional sol-gel method, to form the polymer/inorganic poly(MMA-MAA-MPS)/ZnO composite hollow latex particles. With the increase of crosslinking degree would increase the amount of ZnO bonding. Moreover, the poly(MMA-MAA-MPS) hollow latex particles were used as carriers to load with the model drug, caffeine. The release of caffeine from poly(MMA-MAA-MPS) hollow latex particles was investigated. 相似文献