环氧基团含量对改性水性聚氨酯性能的影响

Effect of Epoxy Group Content on the Performance of Modified Waterborne Polyurethane

以聚己二酸-1,4-丁二醇酯二醇(PBA)、异佛尔酮二异氰酸酯(IPDI)、双酚A型环氧树脂为主要原料合成一系列环氧树脂改性水性聚氨酯乳液。研究了不同环氧值的双酚A型环氧树脂(E-20、E-44、E-51)及其添加量对水性聚氨酯乳液状态、胶膜性能的影响。对乳液进行了粒径测试,并进行了胶膜的吸水率、拉伸强度等测试。结果表明,在添加量不变的情况下,环氧值越低,乳液粒径越大,胶膜吸水率越低,拉伸强度越高;在环氧值不变的情况下,随着环氧树脂添加量的增加,乳液粒径逐渐增大,胶膜吸水率降低,拉伸强度先增加后降低,断裂伸长率降低。使用E-20型的环氧树脂,添加量为5%时,乳液的平均粒径为83.8 nm,胶膜拉伸强度为57.3 MPa,基材附着力达到0级,铅笔硬度为6H,综合性能最佳。

A series of epoxy resin modified waterborne polyurethane emulsions were prepared with polyadipic acid-1,4-butanediol glycol diol(PBA),isophorone diisocyanate(IPDI)and bisphenol A epoxy resin as the basic raw chemical materials.The effects of bisphenol A epoxy resins(E-20,E-44,E-51)with different epoxy values and their addition amounts on the status of waterborne polyurethane emulsion and the performance of the film were researched.The particle size of emulsion was tested, and water absorption and the mechanical properties, such as, tensile strength was tested on the film.The results show that in the case of the same amount of addition, when the epoxy value is lower, the emulsion particle size gets larger, the water absorption rate of the film is lower, and the tensile strength becomes higher.In the case of the same epoxy values, with the increase of epoxy resin addition, the emulsion particle size gradually increases, the water absorption rate decreases, the tensile strength firstly increases and then decreases, and the elongation at break reduces.The waterborne polyurethane with the best comprehensive properties is obtained when E-20 epoxy resin is used and the amount of addition is 5%.The average particle size of the emulsion is 83.79 nm, the tensile strength of the adhesive film is 57.3 MPa, the substrate adhesion reaches 0,and the pencil hardness is 6H.The overall performance is the best.