水性聚氨酯的合成及可剥涂料的性能研究

目的以水性聚氨酯为主要成膜物质,制备一种耐水性良好且涂层整体可剥的保护涂料。方法首先采用正交法分析水性聚氨酯的合成工艺,并通过测试红外图谱、存储时间、外观及耐水性,分析三乙胺和H2O含量对产物性能的影响。再以合成产物为基料,加入固化剂聚碳化二亚胺及其他助剂制备水性涂料,通过测试邵氏硬度、附着力、拉伸强度、断裂伸长率、剥离强度及耐水性,分析该水性涂料的可保护性和可剥性。结果红外图谱表明成功合成了水性聚氨酯,得出了自乳化型水性聚氨酯的最佳合成工艺。涂料工艺性和涂层的综合性能良好,涂层可以一次性整体剥离。该涂层附着力为4B,具有良好的耐水性,在室温水中浸泡48 h后,质量基本不变,拉伸强度由37.7 MPa变为33.6 MPa,断裂伸长率由540%变为510%,邵氏硬度仍为82HA。结论聚碳化二亚胺和其他助剂的加入使得涂层具有良好的可剥性和耐水性,且涂层硬度为82HA,对基材能起到一定的保护作用。

Synthesis of Waterborne Polyurethane and the Properties of Strippable Coating

A waterborne polyurethane is used as the main film-forming material to prepare a protective coating with good water resistance. The synthesis process of waterborne polyurethane is analyzed by orthogonal method. The influence of triethylamine and H2O content on the properties of the product is analyzed by testing the FTIR, storage time, exterior and water resistance. Then, the synthesis product is used as the base material, The polycarbodiimide and other additives are used to prepare waterborne coatings. The protective and strippable properties of the waterborne coating are analyzed by testing Shore hardness, adhesion, tensile strength, elongation at break, peel strength and water resistance. the waterborne polyurethane is successfully synthesized, and the optimum synthesis process of the self-emulsifying waterborne polyurethane is obtained. The coating processability and the coating performance are good, and the coating can be peeled off in one time. The coating has good water resistance: After soaking in room temperature for 48 h, the quality is basically unchanged, The tensile strength is changed from 37.7 MPa to 33.6 MPa, the elongation at break from 540% to 510%, and the Shore hardness is still for the 82HA; The addition of polycarbodiimide and other additives makes the coating has good peelability and water resistance, and the coating hardness of 82HA, the substrate can play a protective role.