粉末涂料用酰胺改性聚酯树脂的合成与性能探究

Synthesis and Properties of Amide Modified Polyester Resin for Powder Coatings

首先利用六氢苯酐(HHPA)和4,4-二氨基二苯基甲烷(DDM),常温下在丙酮溶液中合成一种含酰胺键二元羧酸,并将该单体替代部分封端酸引入到聚酯树脂中和聚酯进行共聚,合成了含酰胺键的改性聚酯树脂。通过核磁共振氢谱和碳谱、傅里叶红外光谱、差示扫描量热仪、锥板粘度计等手段对合成单体和改性聚酯树脂进行了性能检测和分析。同时将改性聚酯树脂制成粉末涂料,对涂膜的一些基本性能进行了测试和研究。结果表明,含酰胺键二元酸的加入(1%~4%质量分数)对改性聚酯树脂的玻璃化温度影响不大,每增加1%质量Tg下降约0.5℃;改性聚酯树脂的熔融粘度随之降低,耐热性能得到略微提升,其相应粉末涂料的胶化时间变长,耐候性能有所下降。

Firstly,a kind of dicarboxylic acid containing amide bond was synthesized from hexahydrophthalic anhydride(HHPA)and 4,4-diaminodiphenylmethane(DDM)in acetone solution at room temperature,and the monomer was introduced into polyester resin instead of some end capped acid to copolymerize with polyester,and the modified polyester resin containing amide bond was synthesized.The properties of the monomer and modified polyester resin were tested and analyzed by means of nuclear magnetic resonance,carbon spectrum,Fourier transform infrared spectroscopy,dif ferential scanning calorimeter and cone plate viscometer.At the same time,the modified polyester resin was made into powder coating,and some basic properties of the film were tested and studied.The results showed that the glass transition temperature of the modified polyester resin was not affected by the addition of amide bond containing dicarboxylic acid(1%~4%by mass),Tg decreased by about 0.5℃when 1%mass fraction was added;the melting viscosity of the modified polyester resin decreased,the heat resistance was slightly improved,and the gelation time of the corresponding powder coatings was longer,and the weatherability was decreased.