大分子引发－转移－终止剂

大分子引发－转移－终止剂杨文君，李俊柏，沈家骢（青岛化工学院橡塑工程研究所，青岛，２６６０４２）（吉林大学化学系，长春，１３００２３）关键词聚苯乙烯，聚丙烯酰胺，嵌段共聚，扩链反应，引发－转移－终止剂含有二乙基二硫代氨基甲酸基的有机硫化物或大分子，在...     

以纤维素材料为基质的降解塑料的研究进展

本文详述了以天然高分子纤维素材料为基质的降解塑料的发展。纤维素材料由于其来源丰富,有良好的反应性,优异的生物降解性,无毒性等,因而可用来制备降解塑料．其开发和应用是解决目前世界范围内的“白色污染”的一条理想途径．     

二氧化碳与环氧化物的调节共聚合反应速率

在二氧化碳和环氧化物共聚时加入特定的调节剂，生成有规定的分子量和端基官能度的产物．这种调节聚合的本质是调节剂所含活泼氢与活性中心之间的链转移反应．根据建议的历程，提出了调节共聚速率方程，计算结果与实验一致．     

乙酰化淀粉/DL-丙交酯接枝共聚物的合成及降解性能研究

用醋酸乙烯酯和玉米淀粉反应制备出了不同取代度乙酰化淀粉，再用乙酰化淀粉同DL－丙交酯接枝共聚合成乙酰化淀粉／DL－丙交酯接枝共聚物。研究了原料配比，淀粉取代度对接枝反应单体转化率（C％），接枝率（G％）接枝效率（GE％）和接枝支链数均分子量（Mn)的影响，结果表明在给定的试验条件下接枝共聚反应的C％，G％，GE％和Mn可分别达到40％，225％，80％和1．4万。接枝共聚物在磷酸缓冲溶液和户外土壤掩埋降解实验表明，在160天内样品失重率分别为71％和60％，表明合成的乙酰化淀粉／DL－丙交酯接枝共聚物具有很好的降解性能。     

乳液聚合共聚物玻璃化转变温度及其理论计算

从共聚单体的竞聚率、油相水相分布系数出发,通过动力学模拟计算了丙烯酸丁酯与醋酸乙烯酯乳液共聚物的链结构,并用Johnson公式对其玻璃化转变温度(T_g)进行了理论计算,给出了共聚物T_g及其对应聚合物的重量分布图。发现半连续共聚物有1个T_g,其值随共聚物组成而变化;但一步法共聚物有两个T_g:低温区T_g代表富丙烯酸丁酯共聚物,高温区T_g则代表PVA均聚物。计算结果与实验十分吻合。     

Effect of dimethylaminoethyl methacrylate on the graft copolymerization of ethyl acrylate onto hydroxypropyl methylcellulose in aqueous medium

Graft copolymerization of an ethyl acrylate (EA) and dimethylaminoethyl methacrylate (DMAEMA) monomer mixture onto water-soluble hydroxypropyl methylcellulose was investigated with potassium persulfate (KPS) as the initiator in an aqueous medium. The effects of introducing DMAEMA onto the graft copolymerization and the properties of the resulting latex that was produced were studied systematically. The optimum conditions for the graft copolymerization in terms of percentage of grafting and grafting efficiency were determined. The graft copolymer was characterized by Fourier transform infrared spectra, elemental analyses, nuclear magnetic resonance, transmission electron microscopy, and dynamic light scattering methods. The results suggest that the introduction of the DMAEMA monomer clearly accelerates the initial rate of the graft copolymerization, whereas the grafting parameters decrease significantly with increasing amounts of DMAEMA. These results can be attributed to the relatively large size of the DMAEMA molecule, its redox reaction with KPS, its hydrophilicity in water, and its chain transfer effect. The equilibrium humidity adsorption behavior and acid solubility of graft the copolymer films were also studied.     

淀粉接枝丙烯酸乙酯及其增容性

研究了在挤出机中采用高温和剪切力的作用直接引发淀粉与丙烯酸乙酯的接枝共聚合反应．讨论了反应条件对接枝反应的影响，研究了接枝物在淀粉与聚乙烯共混物中的增容作用．实验结果表明，高温和剪切力可以引发淀粉与丙烯酸乙酯的接枝共聚合反应．接枝物作为增容剂，可以明显地改善淀粉与聚乙烯共混物的力学性能和流变性能．     

Controlled alternating copolymerization of St with MAh in the presence of DBTTC

The copolymerization of styrene (St) with maleic anhydride (MAh) performed at 22 °C in the presence of dibenzyl trithiocarbonate exhibits controlled nature evidenced by: narrow molecular weight distribution, controlled molecular weight and first-order polymerization kinetics. The composition analysis of the copolymers obtained by ¹³C NMR spectra shows the molar fraction of St in obtained copolymers is almost equal to 0.5 throughout the copolymerization. The sequence structure of the copolymer was obtained from DEPT experiments by recording the spectra at π/4 and 3π/4, and then combining them together, the results showed that the copolymers obtained possessed well-defined alternating structure. The experiment shows that charge-transfer-complex formed from St and MAh participates in both initiation and chain growth throughout the copolymerization.     

聚丙烯微孔膜基渐变聚合物的制备,结构与性能的研究

以聚丙烯微孔膜为基材，通过扩散控制原位共聚合的方法在人填充了组成沿膜的厚度方向逐渐改变的无规共聚物，Ｘ－光电子能谱（ＸＰＳ）、全反射红外光谱（ＡＴＲ）以及动态粘弹谱的分析结果。说明所制备得到的合膜具有明显的渐变聚合物性质。     

含丙磺舒高分子药物的合成与表征

非甾体抗炎药丙磺舒以酯键连接到甲基丙烯酸2-羟乙酯上得含丙磺舒单体HP，HP在偶氮二异丁腈引发下均聚、与甲基丙烯酸甲酯共聚合成了含丙磺舒的高分子药物，产物结构经IR，1HNMR和GPC表征。