氯乙烯/邻苯二甲酸二烯丙基酯悬浮共聚特征

对４５℃时的氯乙烯／邻苯二甲酸二烯丙基酯（ＶＣ／ＤＡＰ）的悬浮共聚进行了研究，得到表观竞聚率ｒＶＣ＝０７６９、ｒＤＡＰ＝０３７４．凝胶点对应的ＤＡＰ临界起始浓度在０４６６～０４９３ｍｍｏｌ／ｍｏｌＶＣ之间（聚合转化率为８０～８５％），当ＤＡＰ起始浓度小于临界浓度时，ＶＣ／ＤＡＰ共聚物均为溶胶，溶胶平均聚合度随ＤＡＰ起始浓度和聚合转化率的提高而增大；当ＤＡＰ起始浓度大于临界浓度时，共聚物由溶胶和凝胶组成，凝胶含量随ＤＡＰ浓度和聚合转化率的提高而增加，溶胶聚合度则随ＤＡＰ浓度的提高而减小．在凝胶点前，共聚物的分子量分布随ＤＡＰ浓度的增加而变宽；凝胶点以后，分子量分布随ＤＡＰ浓度的增加而变窄．     

乙烯基单体/N-苯基马来酰亚胺共聚物组成预测、控制和优化

采用递推方法成功地预测了乙烯基单体/N-苯基马来酰亚胺(PMI)共聚物组成随转化率的变化.选择共聚单体种类和用量,控制和优化共聚物组成.针对氯乙烯(VC)/PMI/丙烯腈(AN)三元悬浮共聚合特殊体系的聚合特点和工艺,得到该三元体系的单体选择范围.     

AN/St悬浮共聚体系中AN在水/油两相间分配及其对共聚物组成的影响

研究了丙烯腈/苯乙烯(AN/St)悬浮共聚体系中AN在水/油两相间的分配及其对AN/St共聚物组成的影响.结果表明,AN分配于水/油两相间,使油相AN的含量低于相同单体配料比的本体聚合,导致生成的AN/St共聚物组成偏离本体共聚.为了准确预测进而控制AN/St悬浮共聚物的组成,提出了在考虑AN相分配的基础上计算AN/St悬浮共聚物组成的模型.计算结果与实验值一致,计算中用到的油相实际竞聚率与本体聚合相同,但该悬浮聚合的表观竞聚率随水/油比的变化而发生较大改变.     

增塑化学微交联聚氯乙烯中化学交联和物理交联的协同作用

由氯乙烯／ 邻苯二甲酸二烯丙基酯（ＶＣ／ＤＡＰ） 悬浮共聚合成了化学微交联聚氯乙烯（ＰＶＣ） 树脂,并进行增塑加工．共聚得到的化学交联ＰＶＣ 具有溶胶／ 凝胶分配特性,交联密度较低;化学交联ＰＶＣ 的溶胶和凝胶均存在分子链缠结作用,尤其当凝胶含量较高时,物理缠结对凝胶交联密度有较大贡献．化学交联对增塑ＰＶＣ 结晶性的影响较小,因此在增塑化学微交联ＰＶＣ 中同时存在化学交联网络和以分子链物理缠结点和微晶为交联点的物理交联网络,两者协同影响增塑ＰＶＣ 材料的性能．     

氯乙烯交联共聚凝胶点前的分子量模型与仿真

从氯乙烯(VC)两相聚合的特点出发,根据拟动力学常数法和分子量分布矩理论,建立了VC-微量二烯类单体悬浮交联共聚凝胶点前的分子量模型,并根据模型,对平均聚合度变化作了计算机仿真。     

偏氯乙烯-氯乙烯悬浮共聚物的结晶与熔融性能

研究了聚合温度、共聚物组成、低分子助剂用量等对偏氯乙烯 (VDC) 氯乙烯 (VC)悬浮共聚树脂的结晶度、熔融峰温度的影响 ,并用Florry的聚合物熔点降低理论预测共聚树脂熔点随共聚组成、低分子助剂用量的变化规律 ,为VDC VC悬浮共聚树脂的合成工艺条件和加工性能的改善提供理论基础 .     

氯乙烯/N-苯基马来酰亚胺共聚物组成控制和优化

研究了氯乙烯 /N 苯基马来酰亚胺 (VC/PMI)共聚物组成随转化率的变化 ,体系中共聚物的累积组成偏差小于 0 0 5或 0 1的单体配比范围很小 ,采用加入第三单体丙烯腈 (AN)的方法进行改善 ,并以PMI在共聚物中的累积组成偏差作为控制参数 ,得到了PMI在共聚物中的累积组成偏差小于 0 0 5和 0 1的VC/PMIlAN较优的配比范围 .结合悬浮聚合工艺的特点 ,确定了VC/PMI/AN悬浮共聚的最佳单体配比范围为f1=0 72～ 0 84 ,f2 =0 0 2～ 0 0 4 ,f3 =0 1 2～ 0 2 4 .     

氯乙烯/N-取代马来酰亚胺共聚竞聚率及共聚物组成

研究了氯乙烯(VC)与多种N-取代马来酰亚胺的溶液共聚合,求得各对单体的竞聚率.结果表明,各种马来酰亚胺的竞聚率都远高于VC的竞聚率,即N-取代马来酰亚胺单体的活性均比VC单体活性高.计算得到N-取代马来酰亚胺Q和e值.由于苯环的共轭效应,N-苯基及N-取代苯基马来酰亚胺具有较大的Q值.各对单体的e值差别较大,表明有形成交替共聚物的倾向.此外,还考察了聚合过程中共聚物组成的变化,用递推法预测了这类体系共聚物瞬时和累积组成随转化率的变化.     

三磷丙基异氰酸尿酯—二乙烯苯—醛酸乙烯大孔共聚物的合成及…

根据文献查得的Ｑ，ｅ值，计算了三烯丙基异氰酸尿酯－二乙烯苯－醋酸乙烯三元共聚体系的竞聚率，预测了它们进行共聚的可能性。以甲苯和汽油为致孔剂，采用悬浮聚合的方法合成了此三元大孔共聚物，并研究了致孔剂用量，关联度等对共聚物孔性能的影响。实验发现，此共聚体系在适当条件下，可以制得很高比表面积的大孔共聚体，比表面积可高达１２１４ｍ＾２／ｇ。对合成的共聚物又进行了醇解反应，得到了含羟基的共聚体。     

三烯丙基异氰酸尿酯－二乙烯苯－醋酸乙烯大孔共聚物的合成及其醇解反应

根据文献查得的Ｑ、ｅ值，计算了三烯两基异氰酸尿酯－二乙烯苯－醋酸乙烯三元共聚体系的竞聚率，预测了它们进行共聚的可能性．以甲苯和汽油为致孔剂，采用悬浮聚合的方法合成了此三元大孔共聚物，并研究了致孔剂用量、交联度等对共聚物孔性能的影响。实验发现，此共聚体系在适当条件下，可以制得很高比表面积的大孔共聚体，比表面积可高达１２１４ｍ２／ｇ。对合成的共聚物又进行了醇解反应，得到了含羟基的共聚体。     

KINETICS OF VINYL CHLORIDE (CO) POLYMERIZATION AT HIGH CONVERSION

This paper provides a summarized review on the kinetics of vinyl chloride homopolymerization inthe absence and presence of chain transfer agents, of VC/DAP(diallyl phthalate) copolymerization with chainextension and/or slightly crosslinking functions, and of vinylidene chloride/VC random copolymerization.Models of rate, degree of polymerization or molecular weight, copolymer composition, gel fraction andcrosslinking density were proposed and interpreted mechanistically.     

Studies of the polymerization of diallyl compounds. XLI. Discussion of substantially identical gel points among three isomeric diallyl phthalates

In the bulk polymerization of three isomeric diallyl phthalates, diallyl phthalate (DAP), diallyl isophthalate, and diallyl terephthalate (DAT), no difference in the actual gel point was substantially observed. This interesting gelation behavior is discussed in terms of the correlation between gelation and the difference in cyclization modes, and the difference in reactivity between the uncyclized and cyclized radicals for crosslinking; the nonconsecutive addition in DAT polymerization led to a delayed gelation and the cyclized radical in DAP polymerization showed an enhanced reactivity for crosslinking.     

苯乙烯-双烯A交联共聚凝胶、溶胶的生成与转化

本文结合提取、凝胶色谱等方法测定了苯乙烯-双烯A交联共聚过程的转化率曲线。通过研究发现,凝胶在交联共聚一开始就产生,且整个反应过程都在不断地生成;转化率40％以前几乎无溶胶生成,此后生成的溶胶仍不断地向凝胶转化;刚生成溶胶时其分子量高、分布窄,其后分子量变低、分布变宽;T_g以上温度的热处理发生进一步聚合反应,当双烯A摩尔浓度<3.3×10~(-4)时,溶胶分数增加,A-MA摩尔浓度>5.0×10~(-4)时,凝胶分数增加,这是双烯A悬吊双键及单体苯乙烯进一步反应的结果。     

Studies of the polymerization of diallyl compounds. XXVIII. Copolymerization of monoallyl phthalate with allyl benzoate and diallyl phthalate

The bulk copolymerizations of monoallyl phthalate (MAP) with allyl benzoate (ABz) and diallyl phthalate (DAP) were conducted in the presence of benzoyl peroxide as an initiator at 70°C; copolymers containing allyl alcohol unit were obtained. The copolymer composition was reasonably interpreted in terms of polymerization kinetics, including the partial elimination of phthalic anhydride (PhA) from the MAP growing chain end in its propagation reaction with another monomer. Kinetics of the copolymerization of DAP with MAP were also discussed in detail, and the gel point was additionally evaluated. DAP–MAP copolymer was homogeneously reacted with zinc acetate to produce the polymer gel carrying ionic crosslinkages.     

N-叔丁基-α-苯基硝酸酮调控氯乙烯悬浮聚合

以过氧化新癸酸α-异丙苯酯(Lup188)作为引发剂,聚乙烯醇(PVA)和羟丙基甲基纤维素(HPMC)作为复合分散剂,加入N-叔丁基-α-苯基硝酸酮(PBN)用氮氧自由基在40～70℃下调控氯乙烯(VC)悬浮聚合.PBN能有效控制聚氯乙烯链增长,聚合后期无自加速现象,体现出可控/"活性"自由基聚合的特点.用重量法测定转化率、GPC测定聚合物分子量与分布,研究了引发剂用量、PBN用量以及聚合温度对聚合动力学和聚合物分子量及分布的影响.得到该聚合体系下VC、Lup188、PBN的最佳摩尔配比为10000∶7∶1,最佳聚合温度为50℃,将转化率控制在50%以下时,能得到较窄分子量分布的聚氯乙烯产物.     

Influence of the Nature of Crosslinking Agent on the Oxidation Behavior of Crosslinked Polystyrene‐Supported Polyoxyethylene Bound Permanganate

Abstract

Polystyrene‐supported polyoxyethylene (PSPOE) bound permanganate with varying crosslinking agents have been prepared and used as a new class of recyclable oxidizing agents for low molecular weight alcohols and aldehydes. The effect of the nature of crosslinking agents on the oxidation reactions was studied in detail. The crosslinking agents used were ethyleneglycol dimethacrylate (EGDMA), 1,4‐butanediol dimethacrylate (BDDMA), and 1,6‐hexanediol diacrylate (HDODA). Polymer supports were synthesized by free radical suspension polymerization. Chloromethylation was done using the Friedel‐Crafts reaction. A cyclic polyether type compound was developed by the reaction of functionlized resin with polyethylene glycol (PEG₆₀₀) and sodium. Polystyrene‐supported polyoxyethylene was equilibrated with potassium permanganate in benzene to give the oxidizing agent. The results reveal that the reactivity of HDODA‐crosslinked system shows higher reactivity than the BDDMA, and EGDMA‐crosslinked systems. This is due to higher flexibility of the HDODA‐crosslinked system compared to the BDDMA, and EGDMA‐crosslinked systems. The effect of solvent, temperature, and molar concentration of the reagent on oxidation were carried out using benzoin to benzil as the model reaction. For a less flexibile EGDMA‐crosslinked resin, tetrahydrofuran (THF) is the best solvent, for BDDMA‐crosslinked system dioxane and for the highly flexible HDODA‐crosslinked system CHCl₃ is found to be best. In all cases, the reactivity of the reagent increased with an increase in temperature and molar excess of the reagent.