超浓乳液聚合研究近况

总结了国内外在超浓乳液聚合研究方面的近况 ,包括新的聚合体系及聚合产物结构和性能的研究 ,展示了其在新的聚合物材料开发和应用中的前景和价值。     

20Y3100型丙烯腈阻聚剂的工业试验

介绍了通用电气水处理公司开发的20Y3100型丙烯腈阻聚剂，采用部分取代目前齐鲁丙烯腈装置使用中的对苯二酚（HQ）的技术方案，来提升脱氰塔（T-106）的操作效率。实验证明：对苯二酚（HQ）与20Y3100型丙烯腈阻聚剂搭配使用可发挥1＋1〉2的协同效应，能够有效阻止丙烯腈聚合反应发生，比单独使用HQ效果更为显著。     

Indirect Synthesis of Bis(2‐PhInd)ZrCl2 Metallocene Catalyst,Kinetic Study and Modeling of Ethylene Polymerization

Bis(2‐phenylindenyl)zirconium dichloride (bis(2‐PhInd)ZrCl₂) catalyst was synthesized via the preparation of bis(2‐phenylindenyl)zirconium dimethyl (bis(2‐PhInd)ZrMe₂) followed by chlorination to obtain the catalyst. Performance of the catalyst for ethylene polymerization and its kinetic behavior were investigated. Activity of the catalyst increased as the [Al]:[Zr] molar ratio increased to 2333:1, followed by reduction at higher ratios. The maximum activity of the catalyst was obtained at a polymerization temperature of 60 °C. The rate‐time profile of the reaction was of a decay type under all conditions. A general kinetic scheme was modified by considering a reversible reaction of latent site formation, and used to predict dynamic polymerization rate and viscosity average molecular weight of the resulting polymer. Kinetic constants were estimated by the Nelder‐Mead numerical optimization algorithm. It was shown that any deviation from the general kinetic behavior can be captured by the addition of the reversible reaction of latent site formation. Simulation results were in satisfactory agreement with experimental data.     

EMULSION COPOLYMERIZATION OF ACRYLONITRILE AND BUTADIENE. CALCULATION OF THE DETAILED MACROMOLECULAR STRUCTURE

A novel mathematical model is developed that predicts the detailed macromolecular structure of an acrylonitrile-butadiene rubber (NBR) produced in an industrial emulsion polymerization. The model consists of: (i) a basic module that calculates the monomer conversion and the copolymer composition; (ii) a particle size distribution module; and (iii) a macromolecular structure module that calculates the bivariate chain length distributions of the linear fraction and of each branched topology (characterized by the number of branching points per molecule). From the bivariate distributions, the univariate distributions of molecular weights, copolymer composition, and degrees of branching are obtained. The model was validated from global measurements of conversion, average molecular weights, average composition, and average degrees of branching.     

铜（Ⅱ）盐催化卤代苯酚聚合反应影响因素的研究（Ⅱ）

详细研究了影响多相聚合反应铜（Ⅱ）盐催化卤代苯酚聚合的各种因素．卤代苯酚发生聚合反应的活性次序为：２，４，６－三溴苯酚＞２，４，６－三溴间甲苯酚＞２，４，６－三氯苯酚．用甲醇钠作为碱，反应体系中少量水的存在有利于聚合反应，而过量水则不利于聚合反应．分离出的铜（Ⅱ）盐中，当ＣｕＣｌ２·２Ｈ２Ｏ／ＣＨ３ＯＮａ摩尔比为０．５时对聚合反应有最大的催化活性．并提出了铜（Ⅱ）盐催化的由铜（Ⅱ）－酚氧配合物中间体生成聚合物的单电子转移历程．     

甲基丙烯酸β－羟乙酯合成及其蒸馏阻聚剂研究

用三乙胺作催化剂，对甲基丙烯酸（简称ＭＡ）与环氧乙烷（简称ＥＯ）直接酯化合成甲基丙烯酸β－羟乙酯（简称ＨＥＭＡ）反应进行了研究，对反应机理提出了建议，对减压蒸馏中阻聚剂进行了选择。本研究为获得高纯度ＨＥＭＡ提供了可行的办法及有关实验数据。     

乳胶型附聚剂附聚作用的实验研究

本文研究了以一种胶乳附聚另一种胶乳的基本规律。研究了附聚后乳胶粒粒径及其分布,探讨了各种影响因素。本文发现,随着附聚胶乳用量的增大,存在两个附聚峰。     

N.m.r. study of copolymer of styrene with methyl methacrylate prepared in presence of zinc chloride

In the n.m.r. spectrum of a styrene (Sty)-methyl methacrylate (MMA) copolymer prepared in presence of zinc chloride at 60°C the phenyl protons of the styrene unit appeared as one peak at 3τ, the methoxy protons of methyl methacrylate unit appeared as three peaks at 6.4–6.8τ, 7.1–7.3τ and 7.5τ. The position of these peaks indicated an alternate copolymer. This was further confirmed by estimation of copolymer composition from n.m.r. spectrum and element analysis. The value of ‘σ’ which is the probability of alternating MMA and Sty units having same configuration was also determined and found to be 0.865 ±0.006. It was found that the value of ‘σ’ was a direct function of concentration of zinc chloride.     

Ethylene polymerization with high activity catalysts prepared from titanium tetrachloride and magnesium diene adducts

Magnesium (isoprene)₂ adducts were prepared in THF and transferred to toluene solutions. The products from the reaction of these solutions with TiCl₄ gave highly active catalysts for ethylene polymerization when used with aluminium trialkyl co-catalysts. Results of polymerizations under various conditions are given. Comparison experiments were carried out with catalysts prepared from magnesium myrcene and magnesium diphenyl butadiene adducts. Reaction products of TiCl₄ and magnesium diene mixtures were separated into soluble and insoluble fractions and analysed.