水性聚氨酯木器漆胶膜物性的研究

Study on the Physical Properties of the Film of Aqueous Polyurethane for Wood Paints

以甲苯二异氰酸酯 (TDI)、聚己二酸己二醇酯二醇 (PHA)、二羟甲基丙酸 (DMPA)等为原料 ,采用内乳化法制备了水性聚氨酯 ,研究了NCO与OH摩尔比、PHA相对分子质量及交联剂三羟甲基丙烷用量对水性聚氨酯成膜物性能的影响。结果表明 :通过提高硬段含量和交联度等方法可改善聚氨酯膜的力学性能和耐介质性 ,制得的水性聚氨酯成膜物拉伸强度 2 0 .5 8MPa、邵A硬度90、吸水率 2 .0 % ,在 70 %酒精中浸泡 2 4h增重率 12 .4 % ,性能达到国外同类产品的技术指标。

Water borne polyurethane coating for wood was prepared from toluene diisocyanate, polyhexamethylene adipate glycol and dimethanol propionic acid. The relationship between properties and structure of the film was investigated. The results showed that the mechanical properties and medium resistance of film of polyurethane dispersion could be improved by increasing the content of hard segment and crosslinking degree. And its ultimate property is as follows: the tensile strength is 20.85 MPa, Shore A hardness is 90,elongation at break is 412%, water absorption is 2.03% and ethanol absorptivity is 12.40%. The properties reach the technical index of that of abroad similar product. The polyurethane dispersion can be used for wood paints.