In this work, the influence of initial viscosity on the Trommsdorff effect was firstly investigated, and it was confirmed that 1000100 Pas of viscosity could be a criterion of the Trommsdorff effect. On this basis, a new inverted two-stage extruder was established, the designed ‘blocking unit’ was introduced to the screw configuration, and then the continuous bulk copolymerization of methyl methacrylate (MMA) and styrene (St) was carried out. The results showed that the blocking unit could effectively enhance the residence time of copolymerization, and make the molecular weight distribution of copolymer more uniform. The position of the Trommsdorff effect in the extruder was then determined by the thermal effect of copolymerization, and the mixed monomers were continuously added to effectively utilize the Trommsdorff effect. As a result, the MMA-St copolymers with high molecular weight and narrow distribution were prepared via reactive extrusion, which possessed higher melt flow rate and better thermal stability than pure-PMMA. The present work provides important reference and guidance for the industrialization of bulk free radical copolymerization via reactive extrusion.

在这项工作中，首先研究了初始粘度对 Trommsdorff 效应的影响，并证实 1000100 Pas 的粘度可以作为 Trommsdorff 效应的标准。在此基础上，建立了新型倒置两级挤出机，将设计的“嵌段单元”引入螺杆配置，然后进行甲基丙烯酸甲酯（MMA）和苯乙烯（St）的连续本体共聚。结果表明，嵌段单元能有效提高共聚反应的停留时间，使共聚物的分子量分布更加均匀。然后通过共聚的热效应确定Trommsdorff效应在挤出机中的位置，不断加入混合单体以有效利用Trommsdorff效应。因此，通过反应挤出制备了高分子量、窄分布的MMA-St共聚物，与纯PMMA相比具有更高的熔体流动速率和更好的热稳定性。该工作为反应挤出本体自由基共聚的产业化提供了重要参考和指导。