烷氧自由基热引发机制及诱发苯乙烯聚合反应热失控机理研究

Alkoxy radicals, which play a key role in styrene polymerization, will be focused on and its mechanism of thermal initiating, chain transfer and inducing reaction thermal runaway will be researched. The results will be significant for understanding the essence of styrene polymerization thermal runaway, intrinsically safe design and monitoring and early warning. Firstly, DSC and ARC will be used to research the thermal decomposition of organic peroxide. The free radical and decomposition product composition structure will be tested and analyzed. Dynamics model of alkoxy radicals thermal initiating will be established and its mechanism will be revealed. Secondly, RC1 and VSP2 will be used to research the styrene polymerization thermal effect. The free radical, decomposition product composition structure and viscosity will be tested and analyzed. Based on analyzing the thermal stability and non- compatibility of polymerization product, the relationship between thermal effect and free radical reaction process will be characterized. And then dynamics model of alkoxy radicals inducing styrene polymerization thermal runaway will be established and its mechanism will be revealed. Finally, parametric sensitivity change regulation in styrene polymerization reaction progress will be researched based on free radical reaction dynamics model. And critical criterion of thermal runaway based on free radical reaction will also be established by means of numerical simulation and theory analysis, which will be verified and corrected through RC1 test and large size reaction vessel.

研究针对苯乙烯聚合反应中起关键作用的烷氧自由基的热引发机制、链传递进程和诱发反应热失控的动力学机理开展理论和实验研究，对于科学认识苯乙烯聚合反应热失控本质和开展过程本质安全化设计及监测预警具有重要意义。研究通过有机过氧化物的DSC和ARC热分析实验，结合自由基测试和分解产物组成及结构分析，揭示烷氧自由基热引发机制及影响规律，建立烷氧自由基热引发动力学模型；通过针对苯乙烯聚合反应体系开展RC1和VSP2实验，结合自由基测试和产物黏度及组成结构分析，在对产物的不稳定性和不相容性进行分析的基础上，表征系统宏观热效应和微观自由基反应进程的联系，揭示烷氧自由基诱发苯乙烯聚合反应热失控动力学机理及影响规律，建立诱发热失控反应动力学模型；通过数值模拟和理论分析，基于自由基反应动力学模型研究体系参数敏感性变化规律，建立热失控临界判据，并通过RC1、VSP2实验和放大实验进行验证。

苯乙烯聚合反应由于其反应温度高、产物黏度大，导致换热效率低，一旦搅拌不均匀，极易在反应釜内发生热累积，形成局部热点，进而导致热失控现象。为了探究苯乙烯聚合反应热失控的本质并对聚合反应进行监测预警，本项目以有机过氧化物引发苯乙烯聚合反应为研究对象，对其热危险性进行研究，分析其失控机制，主要内容包括：（1）对典型有机过氧化物引发剂过氧化苯甲酰和过氧化苯甲酸叔丁酯的热危险性及不相容物质对其热分解的影响进行研究，建立了相应的热分解动力学模型，并推测热分解机制，归纳烷氧自由基热引发过程主要影响因素及其相互作用机制和规律，揭示苯乙烯聚合反应烷氧自由基热引发机制；（2）针对苯乙烯聚合反应展开小尺寸和大尺寸实验，研究聚合反应的热失控规律及动力学参数，建立了烷氧自由基诱发苯乙烯聚合反应热失控的模型，实现了对不同条件下聚合反应的失控行为的模拟；（3）求解苯乙烯聚合过程中的质量守恒和能量守恒方程，并结合烷氧自由基诱发苯乙烯聚合反应热失控的进程、影响因素及动力学模型，对聚合过程中的温度和浓度进行预测，并建立了苯乙烯聚合反应的热失控临界判据，实现了对聚合反应失控的提前预警。