苯乙烯—二乙烯苯自由基共聚反应动力学研究  

A Study of Kinetics of Radical Copolymerization of Styrene with Divinylbenzene

作　　者：陈天红[1] 左榘[1] 吴佩强[1] 郑容[1] 

机构地区：[1]南开大学化学系,北京大学化学系

出　　处：《离子交换与吸附》1994年第6期497-503,共7页Ion Exchange and Adsorption

基　　金：国家自然科学基金

摘　　要：本文用气相色谱、激光拉曼、激光散射、ＧＰＣ以及粘度等方法研究了苯乙烯—二乙烯苯的自由基交联共聚反应．求得聚合反应初期的表现速率常数Ｋｓｔ、Ｋｍ－ＤＶＢ及Ｋｐ－ＤＶＢ分别为１．６８×１０－２（小时－１）、３．４３×１０－２（小时－１）及５．５４×１０－２（小时－１）；从悬挂双键含量变化解释分子内环化推迟了凝胶化点；由跟踪检测反应中分子重量、尺寸变化指出宏观尺寸分子的出现使重均分子量（）在凝胶化点发散；讨论了多分散、支化对分子尺寸Ｒｇ（均方旋转半径）、Ｒｈ（流体力学半径）的影响，定量关系为：δ＝Ｒｇ／Ｒｈ＝０．００６１ｅｘＰ（１．４３２ｔ）；拟合了Ｒｈ对反应时间的指数依赖性ＲＡ＝５．１９５ｅｘｐ（０．８７２ｔ），这证实了凝胶化点前属反应控制机理。In this paper, a systematical study of radical copolymerization of styrene with divinylbenzene has been performed by means of GC, Raman scattering, laser scattering,GPC and viscometry. The apparent rate constants at early stage of reaction are kst= 1.68×10-2(hr-1), km-DVB= 3.43× 10-2(hr-1), KP-DVB=5.54×10-2(hr-1), respectively. From thechange of pendant double bond amount, gel point is delayed due to intramolecular cyclization. With the aid of monitoring weight and size of the developing molecules, thereason for M w divergence perhaps is the appearance of macro-size molecules during thecopolymerization. In the meantime, the influence of polydispersity and branching on Rg,Rh was discussed. A formula for it is δ=Rg/ Rh=0.0061exp(1.432t). In addition, aexponential relation Rh = 5. 195exp(0.872t) was obtained by fliting the evolution of Rh withreaction time. So the reaction control mechanism before gel point for this gelationcopolymerization has been evidenced.

关 键 词：苯乙烯 二乙烯苯 自由基 共聚反应 

分 类 号：O632.13[理学—高分子化学] O643.12[理学—化学]