高固体含量新型羟基聚酯的合成与性能

Synthesis and Properties of Novel High Solid Hydroxyl Polyester

采用小分子多元醇与苯酐反应生成含端羧基的半酯,再与环氧化合物开环反应制得系列羟基聚酯,该反应在较低温度(130℃以下)下进行,且不需要二甲苯作为带水剂,具有节能环保的优点。采用聚醚多元醇改性进一步降低聚酯的黏度,探究了多元醇种类、多元醇与酸酐物质的量比、环氧单体种类、聚醚多元醇的种类和添加量对聚酯性能的影响,并研究了聚酯的稀释曲线。利用红外光谱仪、核磁共振氢谱仪、热重分析仪和凝胶渗透色谱仪对树脂进行表征,测试了固化涂膜的机械性能、耐溶剂性和热稳定性。得到的聚酯黏度低至860 m Pa·s(质量固含量80%),相对分子质量为800~2 000,分布系数约为1.12。用其配制的双组分聚氨酯涂料具有优异的理化性能,施工VOC含量低至350 g/L,且涂膜具有较好的热稳定性。

In this paper,it was described that small molecular polyols and phthalic anhydride was reacted to produce half-esters containing terminal carboxyl groups,and then ring-opening reactions with epoxy compounds was used to prepare a series of hydroxy polyesters,which provided the advantages of energy saving and environmental protection,attributing to low reaction temperature(below 130 ℃) and without xylene for refluxing.Additionally,the polyether polyol was used to modify the polyester to further decrease the viscosity,and the effects of the types and amount of polyols,epoxy compounds and polyether polyols on the polyester properties were investigated,the dilution curve of polyester was given.The resins were characterized by IR,^(1)H-NMR,thermogravimetric analyzer and gel permeation chromatograph. The mechanical properties,solvent resistance and thermal stability of the cured films were tested. The viscosity of polyesters was lower enough down to 860 mPa·s(80%solid content),and the molecular weight was ranged from 800 to 2000 with 1. 12 of the polydispersity. The results showed that the two-component polyurethane coatings based on itpresented excellent physical and chemical properties and good thermal stability,and its VOCcontent was as low as 350 g/L.