丁苯吡胶乳机械稳定性能改进研究

在丁苯吡胶乳基本聚合条件的基础上，作者以乳化剂用量及配比、初相比、补加水量、聚合体系pH为研究条件对胶乳的机械稳定性进行了改进。     

接枝胶乳中残留引发剂对ABS白度和色度稳定性的影响

在采用乳液接枝-本体苯乙烯-丙烯腈共聚物(SAN)掺混法生产丙烯腈-丁二烯-苯乙烯共聚物(ABS)的过程中,为了维持上下游生产平衡,接枝胶乳需要在储罐内储存一段时间后再加入抗氧剂,而后进入凝聚单元。当储存环境中有氧气存在时,胶乳中的聚合物会发生氧化,导致最终产品白度和色度稳定性下降。本文通过实验证明,胶乳中残留的引发剂是促使聚合物氧化的关键因素。通过降低储存温度和缩短储存时间,能够有效降低接枝ABS(G-ABS)胶乳在储存过程中聚合物的氧化速度,提升产品白度和色度稳定性。     

氯乙烯-醋酸乙烯酯-马来酸酐乳液共聚转化率和胶乳特性

以十二烷基硫酸钠(SDS)和α-丙烯基烷基酚聚氧乙烯醚(10)硫酸铵(HS-10)为复合乳化体系、偶氮二异丁脒盐酸盐(AIBA)为引发剂,采用间歇乳液聚合合成氯乙烯-醋酸乙烯酯-马来酸酐(VC-VAc-MAH)共聚物胶乳,研究了聚合温度、AIBA用量、SDS和HS-10用量及初始单体投料比对聚合转化率、胶乳稳定性和乳胶粒子粒径的影响。结果表明:MAH的加入使胶乳稳定性下降,加入HS-10虽使聚合转化率略有降低,但胶乳稳定性增加;聚合转化率随聚合温度和引发剂用量的增加而增加;当SDS用量为3%(质量分数)时,胶乳稳定,聚合转化率较大;乳胶粒子粒径随着SDS用量的增加而减小,HS-10用量对乳胶粒子粒径的影响较小;随着投料单体中VAc或MAH含量的增加,聚合转化率降低;固定投料单体组成时,共聚物中VAc和MAH含量随转化率的增加而增加。     

35hPBL聚合技术的改进和工业应用

针对50kt/a丙烯腈－丁二烯－苯乙烯接枝共聚物（ABS）装置改造中采用35h聚丁二烯胶乳（PBL）聚合技术后出现的PBL稳定性差的现象，通过加入阻聚剂终止聚合后期反应、改变调整用碱的浓度，达到了改善胶乳稳定性的目的。PBL的机械稳定性指标由0．0086％提高到0．0035％，接枝聚合的接枝胶含量明显从未改进前的79％增加到83％－85％，使最终产品的冲击强度也明显得到提高。     

丁腈橡胶NBR240S乳化体系的改进

阐述了丁腈橡胶NBR240S聚合过程中，通过改进其原有的乳化体系，改善了胶乳的稳定性，减轻了设备堵挂，胶乳凝聚过程中胶粒流失减少，污水COD值明显降低，达到了长周期稳定运行及提高产品质量的目的。     

一种多官能团乳化剂在羧基丁苯胶乳合成中的应用

试验发现：一种阴离子型兼具非离子性的乳化剂A用于羧基丁苯胶乳聚合体系，可显著提高胶乳的质量，其质量分数即使下降到原配方乳化剂标准用量的25％，也能制备出合格的胶乳；与使用SDS的聚合体系相比，使用乳化剂A的聚合体系的聚合反应及产物质量重复性好，胶乳的钙离子稳定性显著提高。分析发现，乳化剂用量的大小会导致聚合反应机理的差异，从而影响聚合反应及产物质量；在酸性条件下，乳化剂本 身的稳定性也是造成这种差异的原因之一。应用试验结果表明：用乳化剂A代替SDS并在一定范围内改变其用量，不会影响胶乳的应用性能。     

歧化松香酸钾皂对生产丁苯橡胶的影响

研究了以歧化松香酸钾皂作为主乳化剂时，对低温乳液聚合丁苯橡胶的聚合及胶乳稳定性的影响。用紫外导数光谱法定量分析了歧化松香酸钾皂的成分，探讨了歧化松香酸钾皂与胶乳稳定性的关系。结果表明，歧化松香酸钾皂中松香酸钾、新松香酸钾、左旋海松酸钾等含量高是影响丁苯橡胶聚合速率下降的主要原因，歧化松香酸钾皂皂化程度不够、pH值不稳定是影响丁苯胶乳稳定性的主要原因，并提出作为乳液聚合丁苯橡胶的乳化剂，歧化松香酸钾皂中含共轭双键结构的松香酸钾皂质量分数应为0．5％～1．5％，另外对歧化松香酸钾皂进行分析，以放置不分层为宜。     

一种新型结构胶乳聚合釜的设计

胶乳聚合釜足丁苯胶乳生产的关键设备之一，搅拌和传热装置的结构形式直接影响聚合过程进而影响产品质量。本文主要介绍了胶乳聚合釜搅拌器、传热装置设汁中采用的一些新型结构。     

丁苯吡胶乳和羧基丁苯吡胶乳的技术概况

介绍了丁苯吡胶乳（VPL）和羧基丁苯吡胶乳的聚合配方、聚合工艺、聚合方法、产品性能及其RFL浸渍液的配制和在胶帘线中的应用。VPL和羧基丁苯吡胶乳是化学纤维与橡胶粘合的高性能胶粘剂。不同制品、不同工艺、不同应用场合采用不同的VPL和羧基丁苯吡胶乳聚合配方、聚合方法及RFL浸渍液配合技术。羧基丁苯吡胶乳能提高聚酯帘线的耐热粘合性，其RFL浸渍液适用于浸渍子午线轮胎聚酯帘线。     

胶乳的作用及对纸张涂料性能的影响

胶乳加到高岭土悬浮液中能瓦解片状高岭土的聚集 ,提高了涂料的多分散性 ,同时增加了涂料的稳定性。胶乳在涂料中起到粘接颜料粒子及颜料与纸基的作用 ,增强涂层强度。胶乳的粒径和形状、胶乳的稳定性及玻璃化温度等特性影响涂料粘度、流变性等性能。在预涂涂布中 ,选择由高苯乙烯含量聚合的羧基丁苯胶乳可提高涂层抗拉毛强度及纸面光泽度和平滑度 ,有利于面涂涂布     

乳液聚合中乳化剂对聚合物乳液稳定性的影响

简要叙述了聚合物乳液稳定性的测定方法，详细地讨论了乳化剂的类型、用量及加入方式等对丙烯酸酯类聚合物乳液的化学稳定性、机械稳定性及贮存稳定性的影响。     

Effect of ionic liquids on stability of O/W miniemulsion for application of low emission coating products

Room temperature ionic liquids (RTILs) are non-volatile organic salts. They may replace conventional coalescing agents in latex coating thus reducing volatile organic compounds (VOCs) emission as well as improving performance of latex coating products such as better thermal stability, conductivity, and antifouling property. The formation of latex coating containing RTILs can be achieved by encapsulation of RTILs inside particles via miniemulsion polymerization. In this study, the role of RTILs and its concentration on stability of miniemulsion during storage and polymerization were investigated. It has been found that, above a critical concentration (10 wt%), adding more RTILs to oil phase may weaken miniemulsion stability during storage aswell as polymerization. Such observations were consistent with the zeta potential measurement for miniemulsions prepared at the similar conditions. The results obtained here would be a useful guideline for the development of new waterborne coating products with desirable functions and particle sizes.     

Preparation of epoxy resin/acrylic composite latexes by miniemulsion polymerization method

Epoxy resin/acrylic composite latexes were prepared by miniemulsion polymerization. Epoxy resins have a functional epoxy group in them and excellent characteristics, such as heat resistance and good adhesion. Acrylic latexes have weather and water resistance. Combining the epoxy resin and the acrylic latex was an attempt to actualize these advantages. The miniemulsion polymerization method was effective in obtaining the composite latex. A less than 500‐nm droplet size for the monomer preemulsion was necessary to obtain the latex in a stable manner. Dimethylaminoethylmethacrylate and methacrylic acid as the reactive functional monomer with an epoxy group were introduced to the latexes. The effect of the polymerization method of these functional groups on the properties of latexes and their films was investigated. The latex prepared by the two‐stage polymerization method had good polymerization stability, storage stability, and solvent resistance. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 128–133, 2001     

剥离型蒙脱土/复合苯丙乳液的制备及其性能研究

在剥离态Na-MMT（钠基蒙脱土）悬浮液中,以原位乳液聚合法制备剥离型Na-MMT/苯丙复合乳液,通过红外光谱表征复合乳液的组成,研究了Na-MMT含量对复合乳液乳胶粒粒径、转化率、聚合稳定性和存稳定性的影响,通过热重和吸水率表征Na-MMT/苯丙复合乳液的抗水性和耐热性。实验结果表明：Na-MMT质量分数在3.0%以内有利于制备得到稳定性良好的复合乳液,复合乳液乳胶粒粒径和复合乳液涂膜吸水率均先减小后增大,Na-MMT质量分数为3.0%的复合乳液耐热性比苯丙乳液提高30℃。     

Preparation and characterization of polysiloxane–polyacrylates composite lattices by two seeded emulsion polymerization and their film properties

Gamma ray‐induced seeded emulsion polymerization of methyl methacrylate and butyl acrylate was carried out in the presence of polymerizable polysiloxane seed latex, which was obtained by the ring‐opening copolymerization of octamethyl cyclotetrasiloxane (D₄) and tetramethyl tetravinyl cyclotetrasiloxane(VD₄) catalyzed by dodecylbenzene sulfonic acid (DBSA). After the first seeded polymerization, 3‐methacryloxylpropyltrimethoxylsilane (MPS) was added for the second seeded polymerization. The conversion–time curve showed that the first seeded polymerization rate was accelerated much by the polysiloxane seed latex. The final composite lattices also showed good storage stability, mechanical stability, and high electrolyte resistance ability. The morphology of the composite latex particles was found to be a quite uniform fine structure by transmission electron microscopy (TEM). The graft of polyacrylates onto polysiloxane and hydrolysis of MPS were confirmed by Fourier transform infrared (FT‐IR) spectroscopy. The mechanical performance, water absorption ratio, surface properties, and transparency of the latex films were also investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1406–1411, 2007     

HEA-AA-MMA-BA共聚乳液的稳定性

研究了聚合工艺对HEA—AA—MMA—BA（HAMB）共聚乳液聚合稳定性和贮存稳定性的影响，分析了其失稳机理，并提出了适合HAMB体系的乳胶粒总势能修正公式。结果表明，采用预乳化单体滴加工艺，比补加乳化剂的净单体滴加工艺聚合稳定性更好。适当降低聚合温度和预乳化单体滴加速率，有利于提高乳液聚合稳定性和贮存稳定性。透射电镜和中和实验证明，富含羟基乳胶粒之间的氢键作用力是HAMB乳液失稳的重要原因。     

含缩水甘油基／氨基丙烯酸酯共聚物乳液的聚合稳定性

研究了乳胶粒组成对含有缩水甘油基,羧基和胺基的丙烯酸酯多层核壳型乳液聚合稳定性的影响规律,探讨了聚合过程的凝聚机理。研究表明：官能团间的交联凝聚作用和水溶性聚合物的架桥凝聚作用是本体系凝聚物形成的主要原因。     

Preparation and characterization of polysiloxane–polyacrylates composite latices and their film properties

Gamma‐ray induced seeded emulsion polymerization of methyl methacrylate and butyl acrylate was carried out in the presence of a polymerizable polysiloxane seed latex, obtained by ring‐opening copolymerization of octamethyl cyclotetrasiloxane (D₄) and tetramethyl tetravinyl cyclotetrasiloxane (VD₄), catalyzed by dodecylbenzene sulfonic acid (DBSA). A series of polysiloxane seed latices with different molecular weights, vinyl contents and particle sizes was used. The conversion–time curve showed that the polymerization rate was accelerated significantly by the seed latex. The obtained composite latices also showed good storage stability, mechanical stability and high electrolyte resistance ability. By using transmission electron microscopy (TEM), the morphology of the composite latex particles was found to display a quite uniform fine structure. The graft polymerization reactions between the polymerizable polysiloxane and the acrylates were confirmed by Fourier‐transform infrared spectroscopy (FT‐IR) and the graft efficiencies were also studied. The influence of seed content, molecular weight, vinyl content of the polysiloxane and seed latex particles size on the mechanical performance, water absorption ratio, surface properties and transparency of the latex films was also investigated. It was found that the seed content and particles size greatly affect the mechanical performance, water absorption ratio and transparency of the latex films. Copyright © 2005 Society of Chemical Industry     

乳化体系对氟硅改性丙烯酸酯乳液性能的影响

采用不同的乳化体系来制备氟硅改性丙烯酸酯乳液,主要探讨了乳化体系对预乳化液稳定性、聚合稳定性、储存稳定性、转化率、粒径大小与分布以及吸水率的影响。结果表明,在所采用的乳化体系中,由聚氧乙烯-4-酚基醚硫酸铵盐(CO436)与1-丙烯基-α-羟基烷基磺酸钠(COPS-1)组成的复合乳液体系,可制得转化率高达98.85%的稳定乳液,乳液粒径呈单分散分布,乳胶膜的吸水率只有4.31%。     

N-羟甲基丙烯酰胺对硅丙乳液及乳胶膜性能的影响

将N-羟甲基丙烯酰胺(NMA)、端乙烯基聚硅氧烷大单体与丙烯酸酯类单体进行乳液共聚合反应,制备了稳定的自交联型的硅丙乳液。通过聚合过程的动力学,聚合稳定性,乳胶粒的粒径大小和分布,以及乳胶膜的耐水性和力学性能测试,结合乳胶粒的微观形态和胶膜的红外光谱和DSC分析,讨论了NMA的引入及聚合方法对硅丙乳液和乳胶膜性能的影响。结果表明,在NMA适量加入的情况下,聚合反应速度加快,聚合稳定性提高,乳胶膜的耐水性增强,并使乳胶膜的力学性能也得到较大的提高。