利用大分子单体技术合成接枝共聚物

大分子单体和小分子共单体共聚是合成接枝共聚物的重要途径之一。本文综述了大分子单体通过各种聚合方式(自由基共聚、离子型共聚、配位共聚、基团转移共聚和逐步共聚)和普通小分子单体的共聚反应,详细讨论了大分子单体和小分子单体的自由基共聚反应动力学,并简要介绍了接枝共聚物的应用背景。     

液体色谱,凝胶色谱分析低聚芳砜及其双烯大分子单体

本文用液相色谱和凝胶色谱对双酚A、双酚S型低聚芳砜及α,ω-双甲基丙烯酸聚芳砜酯大分子单体进行了组分分析,通过改合成条件、测定数均分子量等辅助手段确定液相色谱各峰的归属,计算其分子量及分子量分布指数,并对两种方法测定的结果进行了比较。用液相色谱观察低聚体每个组分的含量及其反应过程中的消长情况比凝胶色谱清晰。     

新型热反应大分子单体的合成与表征

溶液法合成了一些低分子量的羟端基低聚苯醚砜,并由相转移催化剂将之转为热反应大分子单体——α,ω-双甲基丙烯酸聚苯醚砜酯;用FTIR、~1H-NMR对其结构进行了表征,GPC、VPO对其分子量进行了分析和测定;用DSC、DTA对聚苯醚砜双烯大分子单体的转变温度、热反应过程进行了测定和分析。     

含规整聚环氧乙烷枝链的聚硅氧烷的合成及表征

以萘钾为引发剂，二甲基亚砜为溶剂制备了以烯丙基为末端基的聚环氧乙烷大单体，并利用末端双键的硅氢化反应合成了相对分子质量规整的聚环氧乙烷接枝聚硅氧烷的共聚物。产物经萃取精制后，用ＩＲ、￣１ＨＮＭＲ等方法进行了表征。     

Self‐reinforcing hydrogels comprised of hydrophobic methyl methacrylate macromers copolymerized with N,N‐dimethylacrylamide

Methyl methacrylate macromers were synthesized by a catalytic chain‐transfer polymerization, with number‐average molecular weight values ranging from 600 to 26,000. These macromers subsequently were copolymerized with dimethyl acrylamide in bulk by γ radiation to yield transparent xerogel materials. The copolymerization was confirmed by NMR analyses and by subsequent aqueous extractions of the resultant copolymers. On swelling in deionized water, hydrogels were formed that had significantly higher Young's moduli than hydrogels based on statistical methyl methacrylate/dimethyl acrylamide copolymers of equivalent composition. If macromers of high molecular weight were used, phase separation occurred, resulting in opaque hydrogel compositions. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 810–817, 2000     

聚氧化乙烯大单体与苯乙烯的接枝共聚物对某些有机反应的相转移催化效应

以叔丁氧基钾为引发剂合成了由甲基丙烯酰基封端的聚氧化乙烯大单体,用VPO、GPC与UV进行了表征。其数均官能度接近0.90,分子量分布较窄(Mw/Mn<1.10)。将这类大单体与苯乙烯经自由基共聚,制备了接技共聚物。初步考察了这类接技共聚物对酚类化合物与环氧氯丙烷或β-溴乙苯反应时的相转移催化作用,发现产物收率随接技共聚物中氧化乙烯含量的增加而提高。     

聚氧乙烯大单体与甲基丙烯酸甲酯的共聚合及其共聚物的研究

研究了聚氧乙烯（ＰＥＯ）大单体与甲基丙烯酸甲酯的溶液共聚合，考察了引发剂用量，单体总浓度、投料比、反应时间对共聚物组成和分子量的，ＩＲ、ＨＮＭＲ、ＧＰＣ、ＶＰＯ、ＤＳＣ航透射电等测定结果表明，经纯化的共聚物具有预期的结构，且呈现微相分离，体外人体正常抗凝血浆复钙时间测定结果显示：共聚物的抗凝血明显好于玻璃和ＰＭＭＡ均聚物，且随共聚物中ＰＥＯ含量的增加而增强，经水化处理的共聚物的抗凝血性比未经处理的     

Synthesis, Purification and Characterization of Amphiphilic and Microphase Separated Graft Copolymer Polystyrene-g-Poly(ethylene oxide)

The present paper covers the poly (ethylene oxide) macromer with vinyl benzyl terminal group (PEO-VB) prepared by deactivation of the alkoxide function of mono-functional "living" PEO chains with vinyl benzyl chloride (VBC). The obtained macromers were subjected to careful purification and detailed characterization. A new kind of amphiphilic polystyrene-g-poly(ethylene oxide) (PS-g-PEO) with both mi-crophase separated and PEO side chains was synthesized from radical copolymerization of PEO-VB macromer with styrene monomer. An improved purification method, referred as "selective dissolvation", was established for the isolation of graft copolymers from the grafting products, and the purity and yield of the purified copolymers were satisfactory. The well-defined structure of the purified copolymers was confirmed by IR, 1H NMR and GPC. The bulk composition of the graft copolymers was determined by a well-established first derivative UV spectrometry. Various experimental parameters controlling the copolymeri     

Synthesis and Aqueous Solution Properties of a Novel NonIonic,Amphiphilic Comb-Type Polyacrylamide

Nowadays comb-type polyacrylamides are deemed to be the most promising oil-displacing agent in the field of enhanced oil recovery (EOR). We describe the synthesis of a nonionic, amphiphilic macromer (OPAE) with acrylic acid (AA) and t-octylphenoxypolyoxyehylene (OP) by an esterification reaction. The macromer was then copolymerized with acrylamide (AM) under a free radical initiator system and a comb-type modified polyacrylamide (MPAM) was obtained. The structures of OPAE and the MPAM were characterized by Fourier transform infrared (FTIR), ¹H nuclear magnetic resonance (NMR) and dynamic laser light scattering. In order to compare with partially hydrolyzed polyacrylamide (HPAM), the aqueous solution of the MPAM had a higher apparent viscosity, especially in brine. We suggest that the reason was that the branched chains enhanced the rigidity of the MPAM, and made the molecules have a larger hydrodynamic radius, especially in brine, endowing the copolymer with excellent salt tolerance.