超耐候粉末涂料用聚酯树脂的研究

摘要

To better understand the aging mechanism of the powder coatings and enhance the weatherability of the powder coatings,the polyester resin for superdurable powder coatings was synthesized from complete polycondensation of isophthalic acid (IPA) as main acid in the presence of trimethylolpropane (TMP) as chain extender.The polyester resin was tested by thermogravimetric analysis (TGA).The superdurable powder coatings were boiled in water under high pressure and tested by ultraviolet B (UVB),infrared spectroscopy (IR) and scanning electron microscope (SEM) to study the changes in terms of functional groups and microstructure during the period of aging process.The results showed that the superdurable polyester resin had the optimal properties when the TPM content was 2％ and the IPA content was 100％,meanwhile,the aging mechanism of the powder coatings mainly was diffusion control.%为了提高对粉末涂料老化机理的了解,提升粉末涂料的耐候性能,以三羟甲基丙烷(TMP)为扩链剂,以间苯二甲酸(IPA)为主体酸,采用完全缩聚的工艺合成超耐候粉末涂料用聚酯树脂.对超耐候聚酯树脂进行热重(TGA)分析,对超耐候粉末涂料进行高压水煮、紫外光人工加速老化(UVB)测试,通过红外光谱(FI-IR)、扫描电镜(SEM)探究了粉末涂料老化过程中官能团和微观结构的变化.结果表明:TPM含量为2％、IPA含量为100％时,超耐候聚酯树脂的综合性能最佳,粉末涂料的老化机理主要为控制扩散论.