Exploration of the crystallization shrinkage behaviors of polyphenylene sulfide for residual stress prediction

The crystallization characteristics of semicrystalline polymer matrices in thermoplastic composites significantly influence dimensional stability through additional resin shrinkage, subsequently generating residual stresses that critically affect material performance. It is necessary to analyze the influence of resin crystallization behavior on residual stress. In this paper, a novel test method for the shrinkage strain of polyphenylene sulfide resin was developed based on digital image correlation technology. The shrinkage process of polyphenylene sulfide was divided into heat loss-induced shrinkage and crystallization-induced shrinkage. It was demonstrated that the crystallization behaviors lead to the shrinkage of the resin, with the proportion of crystallization shrinkage reaching up to 86% of the whole shrinkage. The cooling rate can affect the crystallization behaviors of the resin, thereby influencing the crystallization shrinkage. The correlation between the cooling rate and the crystallinity of polyphenylene sulfide was established. In addition, the relationship between the crystallinity of polyphenylene sulfide and its overall shrinkage rate was further explored. The temperature range of crystallization shrinkage of polyphenylene sulfide was determined using the crystallization kinetic equation. The study on the crystallization shrinkage of polyphenylene sulfide provides a method for controlling the shrinkage rate of polyphenylene sulfide, and further refines the prediction of residual stress.