Abstract:

The devolatilization process follows different heat and mass transfer mechanisms due to different volatile contents in polymers. It is of great significance to develop efficient devolatilization technology and equipment based on its determining mechanism. In this paper, different theories, models and characteristics of three consecutive stages of polymer devolatilization process, namely, flash-devolatilization, foam-devolatilization and diffusion-controlled-devolatilization, have been systematically introduced. The intensification methods of devolatilization process have also been reviewed in both engineering and technology perspectives. Correspondingly, new technologies, such as grid falling film reactor, higee, supercritical fluid assistance and ultrasonic enhancement, and their applications were described in detail. Future research directions of polymer devolatilization theory and engineering practice were proposed as following: the coupling mechanism between diffusion-controlled-devolatilization and foam-devolatilization needs to be studied further to establish more precise and universal devolatilization mechanisms; and the grid falling film devolatilization technology is prospective in mass-scale industrial devolatilization process due to its energy efficiency advantages.

Key words: polymer devolatilization, transport processes, volatile compounds, specific surface area, surface renewal, falling film devolatilization device

摘要：

聚合物中挥发分含量的不同导致聚合物脱挥过程遵循不同的热质传递机理，基于脱挥过程关键机制开发高能效的聚合物脱挥技术与装备具有重要工程意义。本文分别简述了闪蒸脱挥、起泡脱挥以及扩散脱挥3种脱挥方式的传递机理、过程特征以及过程模型，在此基础上从脱挥工艺和装备两个方面综述了近年来聚合物脱挥过程强化的手段与方法，并系统介绍了栅缝降膜脱挥、超重力旋转强化脱挥、超临界流体辅助脱挥、超声空化强化脱挥等过程强化新技术及其应用现状，提出了未来聚合物脱挥理论与工程实践的研究方向：一方面仍需深入研究扩散脱挥与起泡脱挥的耦合作用机制，建立精准、普适的脱挥过程模型；另一方面指出立式降膜脱挥技术因其能效优势，有望成为未来大规模工业脱挥器的重要选择。

关键词: 聚合物脱挥, 传递过程, 挥发分, 比表面积, 表面更新, 降膜脱挥器