【作者】 郭文平；

【导师】 张政； 秦霁光；

【作者基本信息】 北京化工大学 ， 化学工程， 1999， 博士

【摘要】 自由基聚合在聚合反应工程中占有举足轻重的地位，在自由基聚合反应过程中，尤其是本体聚合，常常出现凝胶效应和玻璃化效应。经典聚合理论不能解释此类聚合行为，而现有聚合动力学模型还存在不同程度的缺陷。本文根据对已有工作的分析以及对文献数据的初步处理，提出了一个适用于自由基本体聚合的简单实用的三段聚合模型。三段聚合模型的提出使自由基本体聚合反应过程的动力学处理大大简化。反应转化率、聚合产物的数均分子量等可经简单积分得到。文中通过应用该模型计算与大量不同聚合体系的文献数据进行比较，结果表明三段模型在不同聚合体系中具有广泛的适用性。最后，实验合成了聚丙烯酸(钾)高吸水性树脂，考察了不同反应条件对树脂吸盐水性能的影响；采用FT-IR谱法测定了丙烯酸和丙烯酸钾共聚物组成，根据FR，KT和YBR法计算了两单体的竞聚率；并用DSC技术研究了该体系聚合动力学，并以转化率-时间数据验证了三段聚合模型在该体系中的适用性。本文共分七章，其中： 第一章为前言，概述了高分子工业的发展及应用，介绍了几种典型自由基聚合方法及特点。 第二章为文献综述及三段聚合模型的提出，共分五个部分。其中，第一部分较详细地描述了动力学模型研究和发展状况；第二部分对现有动力学模型作了简要评述；第三部分介绍了目前实验技术进展和发现；在此基础上，于第四部分提出了三段聚合模型，其要点如下：1、以经典聚合理论为基础，采用稳态近似假设，长链假设和等活性假设。2、将聚合过程分为低转化率阶段，凝胶效应阶段和玻璃化转变阶段。3、在每个阶段上，各速率常数、引发效率和聚合综合常数保持不变，聚合综合常数仅与温度有关，并服从Arrenius定律。4、各阶段之间的转化为突变。5、当聚合反应温度高于聚合物玻璃化转变温度时，玻璃化效应阶段不再出现。第五部分介绍了本文研究工作的内容和目标。 第三章为三段聚合模型在引发剂引发自由基本体均聚反应中的应用，首先，介绍了自由基聚合反应机理和经典自由基聚合理论；而后根据三段聚合模型推导出转化率-时间变化和数均分子量-转化率变化计算表达式；进而，以甲基丙烯酸甲脂为例，考察了转化率-时间计算表达式式和数均分子量计算表达式的适用性，并根据文献实验数据得更多还原

【Abstract】 Free radical polymerization plays a key role in modern polymerization reaction engineering. In free radical polymerization, gel effect and glass effect are two common phenomena , which are especially pronounced in bulk systems. Classical free radical polymerization theory, however, can not account for such complex phenomena, and the kinetic models thus far proposed have suffered from some adjustable parameters and/or parameters that can not be evaluated experimentally, and the predictions of these models against experimental results are not satisfying. In this dissertation, a simple and useful model, Three-Stage Polymerization Model(TSPM), proposed on the basis of recent experimental evidences and our elemental data processing of literature kinetic experiment results, is presented to account for the polymerization kinetics of such phenomena and the model covers the entire conversion range. In TSPM, the calculation of conversion and number-average polymerization degree can be simply achieved. In order to investigate its applicability, TSPM is applied to several polymerization systems and model predictions are compared with numerous literature kinetic experiment data. Finally, polypotassium acrylates, a very important kind of super absorbent polymer, are synthesized and the effects of different reaction conditions, such as initiator amount, reaction temperature, cross linking agent amount and types, on the absorbency capacity of the polymers are investigated. The reactivity ratio of acrylic acid with potassium acrylate is obtained by analysis of copolymer composition with the use of FT-IR technique. Also, the polymerization behavior of this system is investigated by DSC technique and the applicability of TSPM is tested against the experiment results. Seven chapters are consisted in this dissertation.Chapter 1 is the preface, which briefly describes the application and development of polymer industry and the characteristics of four most important polymerization methods.Chapter 2, which consists five parts, regards to the reference review in related areas of this dissertation and the proposition of TSPM. First, the kinetic models for free radical polymerization are reviewed. Then, the new advances and discoveries of modern experimental technique are summarized, on the basis of which TSPM is proposed. The key points of TSPM is更多还原