三种油型改性醇酸聚氨酯树脂耐人工加速老化性能研究

QUV Weatherability of Alkyd Polyurethane Resin Modified with Different Kind of Oil

利用合成脂肪酸、椰子油或豆油改性醇酸树脂,与HDI固化剂混合后制备白色聚氨酯膜,通过QUV试验研究了不同油型改性醇酸聚氨酯涂膜的色差(△E)、失光率和黄变(△b)等情况。结果表明:在1 000 h试验中,涂膜△E主要由△b引起,而失光率很小,即粉化很小;在耐人工老化光泽损失方面,椰子油改性树脂为2级,另2种均为1级;这3种改性醇酸树脂耐黄变性能的优劣顺序为合成脂肪酸改性树脂>椰子油改性树脂>豆油改性树脂。

An alkyd resin was modified with synthetic fatty acid,coconut oil or soybean oil respectively,and mixed with hexamethylene diisocyanate （HDI） to form white polyurethane films.The chromatic aberration （△E）,luster difference （△G） and yellowing （△b） of the three polyurethane films modified with different kinds of oils were investigated by QUV test.The results showed that the △E variation of the films was mainly subject to △b variation,meanwhile,the △G varied slightly （i.e.,chalking a little） after QUV test for 1 000 h.And the △G variation for the coconut oil modified resin was at level 2 while the △G for other two types of oil was at level 1.Furthermore,the synthetic fatty acids modified alkyd resin could enable the polyurethane film to show the optimal yellowing resistance,followed by soybean oil modified alkyd resin and coconut oil modified alkyd resin in order.