2-卤代羧酸季戊四醇四酯多官能引发剂合成星状聚苯乙烯  

Synthesis of Star Polystyrene through Atom Transfer Radical Polymerization Using Pentaerythritol Tetra (2 halocarboxylate) as Multifunctional Initiators

作　　者：张士福[1] 罗宁[1] 应圣康[1] 

机构地区：[1]华东理工大学活性聚合研究室,上海200237

出　　处：《华东理工大学学报（自然科学版）》1999年第6期588-590,共3页Journal of East China University of Science and Technology

基　　金：国家自然科学基金;上海市曙光计划;燕山石化研究院资助

摘　　要：用氯乙酸季戊四醇四酯（ＰＴ－Ｃｌ）和２－溴异丁酸季戊四醇四酯（ＰＴ－Ｂｒ）引发苯乙烯的原子转移自由基聚合（ＡＴＲＰ）本体聚合。结果表明：产物的相对分子质量随单体的转化率增加而增加且接近理论值，呈现活性聚合特征；对合成的聚苯乙烯进行水解和醇解表征后显示，以ＰＴ－Ｃｌ为引发剂仅得到了两臂聚苯乙烯，而以ＰＴ－Ｂｒ 为引发剂可以得到３～４ 臂星状聚苯乙烯；以ＰＴ－Ｂｒ为引发剂在［苯乙烯］∶［ＰＴ－Ｂｒ］∶［溴化亚铜］∶［２，２′－联二吡啶］＝ １９２∶１∶２∶６（摩尔比）的条件下研究了产物的臂数与单体转化率的关系，发现多官能引发剂上的卤原子是逐步引发的，单体转化率为３０％ 时得到的聚苯乙烯的平均臂数低于３，单体转化率增加到６０％ 后聚苯乙烯的平均臂数大于３。Pentaerythritol tetrachloroacetate (PT Cl) and pentaerythritol tetra (2 bromoisobutyrate) (PT Br) were synthesized through the reaction between pentaerythritol and chloroacetyl chloride or 2 bromoisobutyl bromide, respectively. The synthesized PT Cl and PT Br were used to initiate the bulk atom transfer radical polymerization of styrene. The results show that the number average molecular weight increases linearly versus monomer conversion and its value approaches to the theoretical value, and that the molecular weight distribution decreases with the increase of monomer conversion. Hydrolysis or alcoholysis of the polystyrene samples were also carried out. The results indicated that only 2 armed polystyrene was obtained by using PT Cl as the initiator, but that 3～4 armed star polystyrene was gained by using PT Br as the initiator. The dependence of the number of arms of the polystyrene on monomer conversion was also investigated. Using PT Br as the initiator and under the conditions of [styrene]∶[PT Br]∶[CuBr]∶[bpy]=192∶1∶2∶6, there are more than 3 arms per polystynene molecule when the monomer conversion exceeds 60%, however, less arms at the conversion of 30%, which suggest that the initiation process may be a gradual one.

关 键 词：季戊四醇四酯 引发剂 PT-CL PT-Br 星状聚苯乙烯 

分 类 号：O632.13[理学—高分子化学] TQ325.2[理学—化学]