核壳丙烯酸聚合物微粒子乳液的合成与解析

本文利用种子乳液聚合方法合成了丙烯酸聚合物乳液,核、壳聚合物的组成分别为：m(MMA)：m(BA)=76：24和m(MMA)：m(BA)：m(AA)=46：51：3;种子乳液和核壳乳液的MFT分别为66℃和28℃。说明最终的聚合物微粒子具有硬核软壳结构;通过SEM拍摄的照片可以清晰地观察到聚合物微粒子的大小,经计算,全部聚合物中的种子粒子数和最终粒子数基本相同,且未发现细小的粒子。说明壳单体的聚合完全是在种子粒子上进行的;本文还对影响聚合物微粒子核壳结构的主要因素进行了探讨。     

高分子微球的研究现状与发展趋势

介绍了乳液聚合制备法、无皂乳液聚合制备法、悬浮聚合制备法、分散聚合制备法和种子聚合制备法等高分子微球的主要制备方法的特点,并对其在制备聚合物微粒子中的研究现状与发展趋势作了概述。     

聚合物微粒子材料制备的研究与发展现状

介绍了聚合物微粒子材料主要制备方法的特点 ,评述了各种方法在制备聚合物微粒子中 ,影响粒子直径的因素及近期研究进展     

聚合物微凝胶的合成及其应用

介绍了新型纳米材料聚合物微凝胶的合成方法，并对该类微粒子表面和内部结构的表征以及应用前景进行了讨论。     

积水化成开发非圆球状及导电型微粒子聚合物开拓液晶面板构件及防带电涂料用途市场

日本积水化成品工业开发出了非圆球状且粒度均一的单分散性微粒子聚合物以及具有导电性的微粒子聚合物。这些微粒子聚合物是以甲基丙烯酸甲酯及苯乙烯为基础，利用该公司自主开发的悬浮聚合技术制造而成的。该公司可制造平均粒子直径在（0．1—200）um之间、     

油溶性氧化还原引发剂引发苯乙烯乳液聚合反应动力学的研究

本文详细地研究了过氧化月桂胺（ＬＰＯ）／Ｎ,Ｎ－二丁基苯胺（ＤＢＡＮ）引发苯乙烯乳液聚合反应的动力学行为。检测了聚合反应速率,聚合物粒子数,以及聚合物的分子量随引发剂ＤＢＡＮ／ＬＰＯ比率的变化。分析这些实验结果,从中发现聚合反应的极限转化率取决于ＤＢＡＮ／ＬＰＯ的比值,表观聚合反应速率是由发生在聚合物粒子中和在单体液滴中的聚合反应两部分组成。聚合反应总速率取决于ＤＢＡＮ／ＬＰＯ的比值。聚合物粒子数     

油溶性氧化还原引发剂引发苯乙烯乳液聚合反应动力学的研究 过氧化月桂酰胺N,N-二丁基苯胺引发行为的研究

本文详细地研究了过氧化月桂酰胺（ＬＰＯ）／Ｎ,Ｎ－ 二丁基苯胺（ＤＢＡＮ） 引发苯乙烯乳液聚合反应的动力学行为。检测了聚合反应速率,聚合物粒子数,以及聚合物的分子量随引发剂ＤＢＡＮ／ＬＰＯ比率的变化。分析这些实验结果,从中发现聚合反应的极限转化率取决于ＤＢＡＮ／ＬＰＯ 的比值,表观聚合反应速率是由发生在聚合物粒子中和在单体液滴中的聚合反应两部分组成。聚合反应总速率取决于ＤＢＡＮ／ＬＰＯ 的比值。聚合物粒子数随ＤＢＡＮ／ＬＰＯ 的比值的增加而增加。而且聚合物的分子量则随ＤＢＡＮ／ＬＰＯ 的浓度增加而减少。并且也讨论了在该反应系统中的聚合物分散指数ＰＤＩ的变化,和聚合物粒子的成核机理及影响粒子分散度的原因     

纳米聚合物微粒的水分散液

微凝胶是内部为三维交联的网络结构、粒径在100nm以下的聚合物超微粒子，利用聚合物本身的性质与微粒子的独特性质，预期可用作提高涂料、涂布剂、粘合剂和树脂改性剂性能的高功能化材料。     

种子溶胀悬浮聚合法制备分子印迹聚合物微球的研究进展

分子印迹聚合物微球是一种具有特异性识别性能的新型高分子材料.种子溶胀悬浮聚合法所制备的印迹聚合物微球可应用于极性环境中,能够满足诸如酶模拟等实际应用环境的要求.本文综述了几种不同的制备分子印迹聚合物微球的种子溶胀悬浮聚合法,并对其研究方向做了展望.     

混合对丙烯腈连续水相沉淀共聚的影响 I.转速和挡板数的影响

以NaClO_3-Na_2SO_3为氧化还原引发剂,进行丙烯腈-丙烯酸甲酯-甲基烯丙基磺酸钠连续水相沉淀共聚。考察了2种桨型下搅拌速度和挡板数对转化率、分子量和共聚物颗粒形态的影响,结果表明,转数提高,则单体转化率升高,聚合物分子量降低,浆液含固率升高,聚合物平均粒径减小,粒径分布变窄,沉降值下降;挡板数增加,则共聚物颗粒形态变差,转化率与粒子表面积和体积有关,而与粒子数无关,符合高转化率下主要聚合场所是聚合物粒子的机理。     

种子聚合法制备PS/PAA核壳微球的研究

设计制备了以疏水性聚苯乙烯(PS)为核、以亲水性聚丙烯酸(PAA)为壳的PS/PAA核壳结构复合微球。首先利用无皂乳液聚合法制备了亚微米级的PS微球,再以其为种子,利用种子无皂乳液聚合法制备PS/PAA核壳微球。在种子聚合阶段,选用AIBN当引发剂,经过红外光谱(IR)表征,表明当使用油溶性引发剂偶氮二异丁腈(AIBN),使其最终形成PS/PAA核壳结构微球。这种方法解决了亲水性较强的单体在以水为介质时在PS微球溶于少量的苯乙烯(St),并在引发聚合之前经过充分的吸附溶胀,可使亲水性单体AAc在PS种子微球表面聚合生成壳层,解决表面不容易直接聚合生成壳层的问题。     

Effect of amount of emulsifier added in the second stage on morphology of composite latex particles

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     

Poly(methyl methacrylate)/polyacrylonitrile composite latex particles with a novel surface morphology

Precipitation polymerization of acrylonitrile in aqueous phase was performed in the presence of submicrometer-sized poly(methyl methacrylate) (PMMA) seed particles. The resulting PMMA/polyacrylonitrile (PAN) composite latex particles showed a novel well-defined surface morphology like rambutan. The formation of such surface structure was ascribed to the facts that PAN polymer is crystalline and scarcely swollen by its monomer. The composite particles had a core/shell structure with a PAN shell surrounding a PMMA core.     

改性聚乙酸乙烯酯乳液的研究

研制了一种改性聚乙酸乙烯酯乳液 ,通过乳化稳定剂聚乙烯醇的缩醛化 ,用丙烯酸进行核壳乳液共聚和添加松香树脂共混相结合的方法 ,成功地解决了通用乙酸乙烯酯乳液的抗水性、抗冻性和抗蠕变性较差的问题     

Morphological prediction and its application to the synthesis of polyacrylate/polysiloxane core/shell latex particles

A theoretical analysis and a morphological prediction of polyacrylate (PA)/polysiloxane (PSi) latex particles with core/shell morphologies were first conducted based on interfacial tensions and relative volumes of the two polymers in the latex system. The results indicated that the normal core/shell morphology particles (PSi/PA), with hydrophobic polysiloxane as the core and with hydrophilic polyacrylate as the shell, can be easily formed. Although the inverted core/shell morphology particles (PA/PSi) with polyacrylate as the core could not be formed in most cases, even if the fraction volume of polysiloxane was larger than 0.872, which is the smallest value of forming a PA/PSi particle, the PSi/PA particles were unavoidably formed simultaneously with PA/PSi particle formation. The synthesis of PA/PSi particles containing equal amounts of polyacrylate and polysiloxane was then carried out using seeded emulsion polymerization. Before the cyclosiloxane cationic polymerization, 3‐methacryloyloxypropyl trimethoxysilane (MATS) was introduced into the polyacrylate seed latex to form an intermediate layer and chemical bonds between the core and the shell polymers. The characterization by transmission electron microscopy (TEM) demonstrated that the perfect PA/PSi core/shell particle is successfully synthesized when both the core and the shell polymers are crosslinked. The experiments showed that both the hardness and water adsorption ratio characteristics of latex films of the PA/PSi particles are in good agreement with those of the polysiloxane film. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2251–2258, 2001     

Preparation and characterization of core–shell polystyrene and polymethylsilsesquioxane structure latex particles by seeded polymerization

Composite polystyrene and polymethylsilsesquioxane (PS‐PMSSQ) latices were prepared by hydrolysis and polycondensation of triethoxylmethylsilane (TEOMS) in the presence of PS seed latices, obtained by gamma ray induced polymerization. Morphology of the composite latex particles was observed by transmission electronic microscopy and their size distribution was measured by dynamic laser light scattering. It was found that if 1 wt% silicon‐containing surfactant (SCS) and 0.4 wt% dodecylbenzene sulphonic acid (DBSA) were both used, core–shell/PS‐PMSSQ latex particles could be prepared at 30 °C. The core–shell structure was further characterized by X‐ray photoelectron spectrometry. With 0.5 wt% SCS or 0.2 wt% DBSA, the capsulation was incomplete. At 0 and 90 °C, the PMSSQ phase penetrated into the seed particles. No core–shell structure was observed when DBSA was replaced by hydrochloric acid or SCS was replaced by poly(ethylene glycol) monooctylphenyl ether. Copyright © 2006 Society of Chemical Industry     

Preparation of monodispersed hollow polymer particles by seeded emulsion polymerization under low emulsifier conditions

In a low emulsifier system, the MMA‐BA‐MAA copolymer emulsions were prepared as seed latices and the seeded emulsion polymerization of MMA‐MAA‐DVB was consequently carried out to prepare carboxylated core particles. The hydrophobic shell was then synthesized onto the core using styrene, acrylonitrile, and divinylbenzene as comonomers. The hollow latex particles were obtained by alkalization treatment of the core‐shell latex particles. The effects of the feeding rate of monomer mixture, contents of emulsifier SDBS and crosslinking agent DVB, and ratio of the monomers during the core stage and shell stage on the morphology and volume expansion of the latex particles were investigated. The results show that the monodispersed hollow latex particles with large size can be obtained when the feeding rate is 0.1 g/min, SDBS content is 0.15 and 0.2 wt % during the core stage and shell stage, respectively, DVB contents are 1% during the preparation of shell copolymers, and the monomer ratio of the core particle to shell layer is 1 : 8. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1505–1510, 2005     

中空聚合物微球的制备——酸含量的影响

采用预乳化滴加工艺结合多段乳液聚合方法先制备聚(甲基丙烯酸甲酯-丙烯酸丁酯-甲基丙烯酸)/聚(苯乙烯-甲基丙烯酸)核壳乳液,随后以碱/酸溶胀处理得到了单分散性优异且中空度为30%的中空聚合物微球.以动态光散射(DLS)、透射电子显微镜(TEM)和场发式扫描电子显微镜(FESEM)等对各阶段乳液聚合的胶粒大小和分布以及形态结构进行了表征.实验考察了种子酸含量对种子和核壳乳胶的特性以及中空聚合物微球形态的影响规律.结果表明,种子制备时的酸用量以30%～35%为宜,核壳胶粒中约85%的酸单元存在于核聚合物内部.另外,探讨了核壳胶粒在碱/酸溶胀处理过程中的中空形成机理.     

Preparation and characterization of core–shell polystyrene–polydimethylsiloxane particles by seeded polymerization

Nanometer scale particles of seed latex were successfully prepared by polymerization induced by gamma rays. By modification of the coupling agent 3‐methacryloxylpropyltrimethoxylsilane (MPS) at the surface of polystyrene (PSt) particles, polydimethylsiloxane (PDMS) was introduced outside the PSt particles and composite latex particles with a core–shell (PSt–PDMS) structure were successfully prepared. Because of the chemical bond linkage between the core and the shell, such a structure is stable. Direct evidence of the core–shell structure was observed by transmission electron microscopy (TEM). In addition the chemical bond linkage was confirmed by Fourier‐transfer infrared (FT‐IR) spectroscopy. An indirect proof of the core–shell structure was given by water absorption ratio determination of the different samples. Copyright © 2004 Society of Chemical Industry     

Morphology and particle size of nanograde polyurethane/polyacrylate hybrid emulsions

Poly(urethane acrylate) (PUA) composite particles were prepared by seeded surfactant‐free emulsion polymerization. The aqueous polyurethane (PU) dispersions were used as seed particles. The diameters of the seed particles of the aqueous PU dispersions and PUA composite latexes were measured by dynamic light scattering. The microstructures of the PUA composite emulsion particles were observed by transmission electron microscopy. The influences of the amount of the hydrophilic chain extender, the types of initiators, and the PU/polyacrylate (PA) weight ratios on the diameters of the aqueous PU and composite emulsions were also studied. The results showed that the PUA composite emulsions formed a core–shell structure with PU as the shell and with PA as the core. The diameter of the PU seed particles and the particle size of the PUA composite emulsions greatly depended on the amounts of the hydrophilic chain extender used in the preparation of the PU seed; when the hydrophilic chain extender concentration was 7.4%, the average diameter of the PUA composite emulsion particles showed the minimum value. The types of initiators and PU/PA weight ratios did not have a significant influence on the diameter of the PUA composite latex particles. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009