Optimization of Crosslinking Conditions for Unsaturated Polyester Preparation Using Styrene Free Crosslinking Agent

The study on the preparation of a styrene-free unsaturated polyester using diallyl phthalate as a cross-linking agent, and the cross-linking reaction conditions for the preparation of unsaturated polyester through cross-linking and curing reaction of this cross-linking agent were studied. In this paper, the effects of the amount of initiator, curing temperature and curing time on the properties of unsaturated polyesters under two initiator systems, benzoyl peroxide (BPO) and tert-butyl peroxybenzoate (TBPB), were studied. Through research, it is found that under the two initiator systems, appropriately increasing the amount of initiator, increasing the curing temperature and prolonging the curing time are all beneficial to improve the tensile strength, flexural strength and thermal deformation temperature of unsaturated polyester, but unsaturated polyester The toughness of the ester is also deteriorated and the impact resistance is reduced. When the amount of initiator, curing temperature and curing time exceed a certain value, the change trend of these properties becomes slower. The initiation temperature required for the BPO initiated system is slightly lower than that of the TBPB initiated system. This study focuses on the preparation of a styrene-free unsaturated polyester using diallyl phthalate (DAP) as a cross-linking agent and systematically investigates the cross-linking reaction conditions. The effects of initiator type (benzoyl peroxide, BPO, and tert-butyl peroxybenzoate, TBPB), initiator content (1%–5%), curing temperature (100–140°C), and curing time (2–6 h) on the mechanical and thermal properties of the unsaturated polyester were evaluated. Experimental results indicate that increasing initiator content, curing temperature, and curing time within optimal ranges significantly enhances tensile strength, flexural strength, and heat deflection temperature (HDT). 本文开展了以邻苯二甲酸二烯丙酯为交联剂制备无苯乙烯不饱和聚酯的研究，并对这种交联剂进行交联固化反应制备不饱和聚酯的交联反应条件进行了研究。本文研究了过氧化苯甲酰（BPO）和过氧化苯甲酸叔丁酯（TBPB）两种引发体系下引发剂的用量、固化的温度和固化的时间等因素对不饱和聚酯性能的影响。通过研究发现，两种引发体系下，适当增 加引发剂的用量、提升固化温度和延长固化时间的，都有利于提升不饱和聚酯的拉伸强度、弯曲强度与热变形温度，但不饱和聚酯的韧性也因此变差，抗冲击性能下降。当引发剂用量、固化温度及固化时间超过一定数值后这些性能的变化趋势变缓。BPO引发体系比TBPB引发体系所需的引发温度略低。