共查询到20条相似文献,搜索用时 66 毫秒
1.
15个乙烯—乙烯基化合物共聚物的取代基参数 总被引:1,自引:0,他引:1
本文应用取代基参数(SCS)方法处理了15个EV共聚物的^13CNMR谱,它们是:(1)乙烯α-烯烃共聚物,即乙烯-丙烯共聚物,乙烯-丁烯-1共聚物,乙烯4-甲基-1-戊烯共聚物,乙烯-己烯-1共聚物和乙烯-辛烯-1共聚物;(2)乙烯-含氧乙烯共聚物,即乙烯-甲基丙烯酸N,N-二甲基胺乙酯共聚物,乙烯-丙烯酸甲酯共聚物,乙烯-丙烯酸共聚物,乙烯-乙酸乙烯酯,乙烯-乙烯醇,乙烯-一氧化碳共聚物(EC 相似文献
2.
用自由基溶液降合方法制备一系列苯乙烯-丙烯酸甲酯线型共聚物,用核磁共振测定了苯基在共聚物中的百分比,在该共聚物的四氢呋喃溶液中,用三氟乙酸汞在共聚物的苯环上进行亲电取代反应,得到可溶性汞化共聚物,由于这类泵化共的可溶于四氢呋喃,二氯甲烷等溶剂,用重沉淀法多次提纯,得到了纯度很高,溶解性较好的含重金属二价汞的共聚物,用红外光谱仪测定共聚物上的汞基团,用原子吸收定量测试共聚中的汞的百分聚代率,结果表明 相似文献
3.
4.
5.
用自由基溶液聚合方法制备一系列苯乙烯-丙烯酸甲酯线型共聚物,用核磁共振仪测定了苯基在共聚物中的百分比.在该共聚物的四氢呋喃溶液中,用三氯乙酸汞在共聚物的苯环上进行亲电取代反应,得到可溶性汞化共聚物.由于这类汞化共聚物可溶于四氢呋喃、二氯甲烷等溶剂,用重沉淀法(Reprecipitation)多次提纯,得到了纯度很高、溶解性较好的含重金属二价录的共聚物.用红外光谱仪测定共聚物上的汞基因,用原子吸收仪定量测试共聚中的汞的百分取代率.结果表明在本文实验条件下,二价示可取代在苯环上,与丙烯酸甲酯基因没有作用. 相似文献
6.
7.
8.
本文采用氧化还原引发体系合成了丙烯腈与马来酸酐共聚物,各首次将此共聚物制成了醇,水分离用的渗透蒸发膜,研究了不同马来酸酐含量的共聚物膜碱中的水解规律,考察了共聚物,料液温度,料液浓度等条件对膜的醇,水分离性能的影响关系以及水解前,后膜性能的变化结果表明,当共聚物中马来酸酐含量大于0.069(摩尔分数)时,水解前,后膜性能有很大的变化,分离因子,渗透通量和膜强度都普遍提高。另外,还发现该共聚物膜与其 相似文献
9.
10.
11.
B. Wunderlich 《Angewandte Chemie (International ed. in English)》1968,7(12):912-919
Simultaneous as well as successive polymerization and crystallization is possible. While crystallization after polymerization usually produces folded chain lamellar crystals, crystallzation during polymerization frequently produces fibrillar extended chain crystals. 相似文献
12.
R. C. Potter Christel Schneider M. Ryska D. O. Hummel 《Angewandte Chemie (International ed. in English)》1968,7(11):845-856
Previously it was generally assumed that high energy radiation could only initiate radical polymerization in solutions of monomers. However, examples of radiation-induced polymerization have recently become known that proceed via an ionic mechanism. Thus, solutions of a monomer can be polymerized ionically, preferably in the presence of a solid, at low temperatures. Suprisingly, this may also be accomplished with ultra-pure, mainly anhydrous systems, even at room temperature. The nature of the ions has not yet been fully elucidated. 相似文献
13.
自由基聚合动力学是高分子化学教学和学习中的重要内容。本文讨论了建立自由基聚合微观动力学模型的三个简化条件和三个基本假设,三个简化条件和三个基本假设是微观动力学研究聚合速率和聚合度的基础;同时也较为深入地探讨了动力学链长的物理意义、利用动力学链长概念建立起来的平均聚合度计算通用公式以及该公式的使用条件。 相似文献
14.
15.
K. Weissermel E. Fischer K. Gutweiler H. D. Hermann H. Cherdron 《Angewandte Chemie (International ed. in English)》1967,6(6):526-533
A survey of the possible modes of polymerization of trioxane is followed by a discussion of current ideas concerning the course of the polymerization. The polymerization, which involves ring cleavage, is characterized by a number of side reactions of the growing polyoxymethylene cations, such as chain transfer, transacetalization, and hydride shift. These reactions not only determine the nature of the end groups and the molecular weight of the resulting polyoxymethylenes, but are also responsible for their chemical and molecular uniformity. Special emphasis is placed on the role of the monomeric formaldehyde formed during the polymerization of trioxane. 相似文献
16.
ABSTRACT The radiation-induced solid-state polymerization of acenaphthylene was carried out under vacuum at room temperature. The monomer and obtained polymer samples were investigated by UV, FTIR, DSC, TG, and powder X-ray diffraction methods to characterize the polymer and elucidate the polymerization mechanism. The polymer samples were crystalline with melting points ranging in 380-390°C interval. Polymerization takes place through vinyl groups by a radical mechanism and crystal structure of monomer and polymer studied by powder X-ray diffraction were quite similar. The space group for both were P22 1 2 and cell parameters: a = 784.2 (6), b = 798.1(6), c = 1417.0(1) pm for monomer, and a = 791.7(8), b = 803.8(7), c =1431.0(1) pm for polymer. The similarity of crystal structures shows a topotactic polymerization of monomer. 相似文献
17.
应用NMR技术、激光拉曼光谱和硅钼酸方法研究了碱性硅铝酸盐聚合反应中铝酸根离子和硅酸根离子的存在状态及其变化.发现聚合反应是低分子量硅铝酸根离子之间或低分子量硅铝酸根离子与低分子量硅酸根离子之间的反应. 相似文献
18.
环硅氧烷在亲核或亲电催化剂、温度或辐射作用下,可开环聚合生成线型聚硅氧烷,聚合方法主要有本体聚合和乳液聚合.本体聚合可分为阴离子聚合和阳离子聚合,阴离子聚合就是在碱性催化剂(亲核试剂)作用下,使环硅氧烷开环聚合成线型聚硅氧烷的过程;阳离子聚合就是环硅氧烷在酸性催化剂(亲电试剂)作用下的开环聚合反应.乳液聚合则是单体和水(或其它分散介质)并用乳化剂配成乳液状态进行聚合,按所采用的乳化剂种类不同,主要有阴离子型和阳离子型两种类型.本文总结了近几年国内外环硅氧烷本体聚合和乳液聚合的开环聚合机理及动力学研究情况,并对今后此方面的研究进行了展望. 相似文献
19.
Suqiu Jiang Prof. Hanchu Huang 《Angewandte Chemie (International ed. in English)》2023,62(13):e202217895
The development of chain-growth click polymerization is challenging yet desirable in modern polymer chemistry. In this work, we reported a novel chain-growth click polymerization based on the thiol-Michael reaction. This polymerization could be performed efficiently under ambient conditions and spatiotemporally regulated by ultraviolet light, allowing the synthesis of sulfur-containing polymers in excellent yields and high molecular weights. Density functional theory calculations indicated that the thiolate addition to the Michael acceptor is the rate-determining step, and introducing the phenyl group could facilitate the chain-growth process. This polymerization is a new type of chain-growth click polymerization, which will provide a unique approach to creating functional polymers. 相似文献