Deng Rong, Jiang Tuanhui, Zhang Chun, Zeng Xiangbu, Liu Bujin, Yang Jingkui, Li Shengnan, Gu Jun, Gong Wei, He Li
College of Materials Science and Metallurgy Engineering, Guizhou University, Guiyang 550025, China.
National Engineering Research Center for Compounding and Modification of Polymeric Materials, Guiyang 550014, China.
Polymers (Basel). 2021 May 1;13(9):1468. doi: 10.3390/polym13091468.
In this paper, the dynamic foaming process of micro-foaming polypropylene (PP) in different foaming environments in real time was obtained via a visualization device. The relationship curve between cell number () and foaming time () was plotted, and then the nucleation kinetics of foam cells was analyzed. Results showed that the formation rate of cells changed obviously with the variation of melt temperature and the content of the foaming agent. The - curves presented a typical "S" shape, which indicated that the appearance of the cell number increased slowly in the initial foaming period, then increased rapidly in a short time, and finally maintained a certain value. When a certain pressure was applied to the PP melt, the external force had a great influence on the - curve. With the increasing external force, the rate of cell formation increased rapidly, and the shape of the - curve changed from "S" to "semi-S" without an obvious slow increase. The investigation of the - relationship in the PP dynamic foaming process under different foaming environments could provide effective bases for improving the foaming quality of injection molding foaming materials.
本文通过可视化装置实时获取了微发泡聚丙烯（PP）在不同发泡环境下的动态发泡过程。绘制了泡孔数量（）与发泡时间（）之间的关系曲线，进而分析了泡沫泡孔的成核动力学。结果表明，泡孔的形成速率随熔体温度和发泡剂含量的变化而明显改变。-曲线呈现典型的“S”形，这表明在初始发泡阶段泡孔数量的增加较为缓慢，随后在短时间内迅速增加，最终保持一定值。当对PP熔体施加一定压力时，外力对-曲线有很大影响。随着外力增加，泡孔形成速率迅速提高，-曲线形状从“S”形变为“半S”形，且无明显的缓慢增加阶段。对不同发泡环境下PP动态发泡过程中-关系的研究可为提高注塑发泡材料的发泡质量提供有效依据。
