Study on emulsion and suspension in situ polymerization

A novel and simple method of emulsion and suspension in situ polymerization was designed for preparing a composite of polystyrene containing core–shell emulsion particles. The advantage of this method was that it did not need a complex process, such as emulsion breaking, washing, drying, and so on, during transforming from emulsion polymerization to suspension polymerization. First, the core–shell particles of poly(styrene/bisphenol A dimethyl methacrylate)/polystyrene [P(St/BPADA)/PS] with crosslinking structure were synthesized by emulsion polymerization. Then the latex was broken with electrolyte dripping and the emulsion particles became swollen and transformed into the monomer in the suspension polymerization system. Thus the emulsion and suspension in situ polymerization could be carried out successfully. The mechanism of the process was investigated in detail. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 404–412, 2005     

与ABS乳液聚合过程有关的一些基本技术问题

笔者简要介绍了ABS树脂的概况和我国ABS树脂的发展过程、供需情况，阐述了乳液接枝．掺混法在ABS树脂生产中的重要地位，提出了乳液接枝-掺混法ABS树脂生产中与基础胶乳合成、乳液接枝共聚、凝聚等过程有关的一些基本技术问题。为我国ABS的进一步开发和形成具有自主知识产权的ABS树脂生产技术提供了丰富的研究内容。     

Synthesis and characterization of polystyrene/layered double‐hydroxide nanocomposites via in situ emulsion and suspension polymerization

Polystyrene (PS)/ZnAl layered double‐hydroxide (LDH) nanocomposites were synthesized via in situ emulsion and suspension polymerization in the presence of N‐lauroyl‐glutamate surfactant and long‐chain spacer and characterized with elemental analysis, Fourier transform infrared spectrum, X‐ray diffraction (XRD), transmission electron microscopy (TEM), and thermogravimetric analysis. The XRD and TEM results demonstrate that the exfoliated ZnAl–LDH layers were well dispersed at molecular level in the PS matrix. The completely exfoliated PS/LDH nanocomposites were obtained even at the 20 and 10 wt % LDH loadings prepared by emulsion polymerization and suspension polymerization, respectively. The PS/LDH nanocomposites with a suitable amount of LDH showed apparently enhanced thermal stability. When the 50% weight loss was selected as a comparison point, the decomposition temperature of the exfoliated PS/LDH sample prepared by emulsion polymerization with a 5 wt % LDH loading was about 28°C higher than that of pure PS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3758–3766, 2006     

淀粉/AA/AM/MA反相悬浮法合成高吸水树脂

以含阻聚剂的工业级丙烯酸(AA)、丙烯酸甲酯(MA)及木薯淀粉、丙烯酰胺(AM)为原料,采用反相悬浮法,使用自配分散剂,环己烷为连续相,过硫酸钾和亚硫酸氢钠为引发剂,N,N-亚甲基双丙烯酰胺为交联剂合成了高吸水树脂。结果表明,最佳工艺条件为:m(淀粉)∶m(AA)∶m(AM)=1.0∶4.5∶0.9,MA、交联剂加入量分别为5.0%,0.3%(相对AM和AA总质量),引发剂(两次引发)浓度分别为2.0,13.5 mmol/L,油水比例为1.90∶1.00(体积比)。在上述条件下制得的树脂的吸水率≥600 g/g,吸盐率≥60 g/g,环己烷回收率为97.3%。由于引入适量的MA,产物吸水率和吸盐率提高了20%,产物形态由最初的粘接颗粒变成分散颗粒。     

Fabrication and characterization of nanoencapsulated epoxy resin/crosslinked PMMA shells with in situ polymerization via phase inversion emulsion (PIE) method

Encapsulated epoxy resin healing agents with poly(methyl methacrylate (PMMA) as a thermoplastic polymeric shell are suffered from leakage of the core after a while. This problem leads to loss of their performance and its ability in self-healing systems. One way to stop or reduce the leakage of the core is crosslinking the PMMA shell. In this study, nanoencapsulation of epoxy healing agent with crosslinked PMMA as shell was carried out by in situ polymerization via phase inversion emulsion method. Ethylene glycol dimethacrylate was employed as crosslinking agent. Nonionic (SPAN 60) and ionic (sodium dodecyl sulfate) surfactants were used for competitive adsorption and phase inversion in emulsion system. Chemical structures, morphologies, and thermal properties of nanocapsules were characterized by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis, respectively. SEM investigations showed that nanocapsules had a particle size of less than 100 nm with a narrow particle size distribution. Efficiency of nanoencapsulation was equal to 83.5%. And synthesized nanocapsules had at least 37% core contents. Nanocapsules with crosslinked shell were able to maintain liquid core up to 18 weeks, while, noncrosslinked shell lost core content after 14 weeks. It seems that low crosslink density has no effect on capsule durability. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48793.     

原位乳液聚合法制备改性蒙脱土及其表征

通过原位乳液聚合的方法制备改性蒙脱土,在聚合之前,可聚合的小分子先接枝到蒙脱土的表面或层间,然后加入苯乙烯单体引发聚合,使聚合物大分子接枝到蒙脱土的表面和层间。十六烷基三甲基溴化铵(CTAB)在乳液聚合改性蒙脱土的过程中既是插层剂又是乳化剂。X射线衍射分析表明,经过处理引入了CTA+和PS大分子使得层间距扩大;红外、热重法分析表明,小分子和大分子已接枝到蒙脱土上。蒙脱土的存在影响了聚合反应动力学,并就小分子的影响作了简单的讨论。     

Synthesis and characterization of PMMA/SiO2 nanocomposites by in situ suspension polymerization

Poly(methyl methacrylate) (PMMA)/SiO₂ nanocomposites were prepared by in situ suspension polymerization. Two types of modified methods were used to modify nano‐SiO₂: one was modification by γ‐methacyloxypropyl trimethoxy silane (KH570) and lauryl alcohol (12COH) while the other was grafting PMMA onto the surface of KH570 treated SiO₂. Transmission electron microscopy (TEM) and Fourier transformed infrared (FTIR) were used to characterize the structures of the nanocomposites. The influence of synthetic conditions, for instance, surface modification, initial SiO₂ contents and reaction temperature, on the microsphere's size and molecular weight of the extracted PMMA were studied by gel permeation chromatograph (GPC) and optical microscopy (OM) in details. Thermal property of the nanocomposites was investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results indicate that the presence and content of SiO₂ have a vital effect on the shape and size of the nanocomposite microspheres, as well as molecular weight of the extracted PMMA. Grafting polymer to the surface of SiO₂ is an effective way for the purpose of effective in situ suspension polymerization. Compared to pure PMMA, the thermal properties of the nanocomposites were improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

发展我国的ABS树脂产业

介绍了我国ＡＢＳ树脂的产业状况,并就我国的ＡＢＳ树脂产业如何面向２１世纪,详细地提出了几点建议。     

核/壳型ACR乳液的聚合研究

采用预乳化工艺，种子聚合法，通过甲基丙烯酸甲酯(MMA)说明丙烯酸丁酯(BA)接枝共聚反应，制得具有核／壳结构的丙烯酸酯类抗冲击改性剂(ACR)乳液，讨论了乳化、剂用量、引发剂用量、交联剂用量及反应温度对乳液聚合和PVC性能的影响。     

2012年ABS树脂生产与市场分析

综述了2012年国内外ABS(丙烯腈-丁二烯-苯乙烯)树脂生产商的生产能力和实际产量、国内外ABS市场和价格,对国内ABS树脂技术现状及其市场发展趋势进行了分析和预测。另外,还介绍了国内外科研开发、技术进展以及新产品开发情况,并针对国内ABS树脂装置提出了几点建议。     

ABS树脂光泽度与黄色指数的测定

使用Color-view分光光度计同时测定了几个常用ABS树脂的光泽度和黄色指数(YI),着重试验分析了不同的样品规格或尺寸对测定结果的影响。结果表明:样片的厚度不仅对光泽度的测定结果造成了影响,而且对黄色指数的测定结果也形成了较为明显的影响;同时样片上是否有加盖物及加盖物的颜色对测定结果也构成了一定程度的影响;另外,样品的形式对黄色指数的测定结果形成了显著的影响。     

橡胶粒子粒径对ABS树脂结构与性能的影响

采用乳液技术在聚丁二烯(PB)和丁苯橡胶(SBR)乳胶粒子上接枝共聚苯乙烯和丙烯腈合成了PB质量分数为60％的ABS接枝粉料,将其与苯乙烯-丙烯腈共聚物(SAN树脂)熔融共混获得了一系列不同组成和结构的丙烯腈-丁二烯-苯乙烯共聚物(ABS树脂),研究了橡胶粒子粒径对ABS树脂的形态结构、力学性能的影响.结果表明,PB和SBR橡胶粒子的粒径分别为0.3μm和0.05 μm左右时,橡胶粒子的粒径对ABS树脂力学性能的影响十分显著.单独采用小拉径SBR橡胶粒子不能有效地增韧SAN树脂,而大粒径PB橡胶粒子对SAN树脂具有良好的增韧效果.     

有机硅改性丙烯酸酯微乳液的合成研究

以八甲基环四硅氧烷(D4)、-γ甲基丙烯酰氧基丙基三乙氧基硅烷(KH570)和六甲基二硅氧烷(MM)为原料,在Me4NOH催化和二甲基亚砜(DMSO)促进作用下,通过本体聚合合成了侧链含双键的有机硅大分子,可用红外光谱图测定分子结构。采用微乳液聚合法,将丙烯酸酯单体、有机硅大分子单体进行自由基聚合,制备有机硅改性丙烯酸酯微乳液。利用5因素4水平正交实验优化出最佳工艺参数:乳化剂用量为3%,有机硅大分子的用量为9%,单体配比为0.76,异丙醇用量为1.5%,可获得高稳定性乳液,成膜各项性能提高。     

ABS树脂国内外市场分析及预测

综述了国内外ABS树脂生产商的生产能力和实际产量、国内外ABS市场和价格,对国内ABS技术现状及其市场发展趋势进行了分析和预测。另外,还介绍了国内外科研开发、技术进展以及新产品开发情况,并针对国内ABS装置提出了几点建议。     

ABS树脂市场分析及预测

综述了2008年国内外ABS树脂生产商的生产能力和实际产量、国内外ABS市场和价格，对国内ABS技术现状及其市场发展趋势进行了分析和预测。另外，还介绍了国内外科研开发、技术进展以及新产品开发情况，并针对国内ABS装置提出了几点建议。     

Synthesis and characterization of fluoropolymer modified polyacrylate in emulsion polymerization

A novel method to produce fluorine‐containing polyacrylate emulsion is presented. It is prepared by the copolymerization of n‐methyl methacrylate, n‐styrene, n‐butyl acrylate, and α‐methacrylic acid in the presence of swollen particles of PTFE. The structure and properties of the polymers are characterized by GPC, PSD, SEM, and XPS. The number‐average molar mass (Mn) 51,332, and the polydispersity 5.8688 are obtained. The mean diameter of latex particles is 300nm. Scanning electron microscopy reveals that particles of the emulsion are well dispersed. Meanwhile, the F_1S content of the surface on the latex membrane is 8.99%. It is shown that the method of mixing micron and nanometer‐sized particles should be made the next step of research. It is also proved that inertia polymers can be used in emulsion property modification. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 558–562, 2006     

ABS树脂的色差分析

通过3组不同的考察方法,测试了ABS树脂的白度及黄色指数,通过计算数值比较产品色差。通过对放置时间、烘干时间以及对不同尺寸样件的色差分析,提出了控制ABS树脂色差的方案。     

ABS树脂阻燃剂的研发进展

介绍了ABS树脂阻燃剂的研究开发进展,指出了其今后的发展趋势。     

ABS树脂国内市场回顾与展望

ABS树脂是一种综合性能优异的热塑性树脂。本文对2000年-2005年我国ABS树脂国内市场供需状况、消费状况和市场价格进行了回顾,并对2006年-2010年国内ABS市场供需状况和市场竞争情况进行了展望。     

论我国ABS树脂的发展

介绍了我国ＡＢＳ树脂生产的技术路线和生产装置,对今后我国ＡＢＳ树脂生产的发展提出了看法和建议。