聚氨酯改性环氧树脂胶粘剂的制备及性能研究

Study of preparation and properties on epoxy resin adhesive modified by PU

由端-NCO基聚氨酯(PU)预聚物与环氧树脂反应,制备了PU接枝改性环氧树脂。着重探讨了PU预聚物的含量、活性稀释剂的含量和异氰酸酯结构等因素,对改性环氧树脂的粘度和粘接性能的影响。实验结果表明,该改性环氧树脂的粘度随着PU预聚物含量的增加而逐渐增大,随着活性稀释剂含量的增加而逐渐降低,而且在相同的条件下,用不同的二异氰酸酯改性环氧树脂的粘度大小次序为:IPDI型>MDI型>TDI型;该改性环氧树脂在PU预聚物含量为20%时,对铝片/铝片的剪切强度最大(7.82 MPa);在PU预聚物含量为10%时,对铁片/铁片的剪切强度最大(11.70 MPa),而且TDI型和IPDI型改性环氧树脂的粘接性能明显好于MDI型改性环氧树脂。

Epoxy resin grafted and modified with polyurethane（PU） was prepared by reaction of-NCO-terminated PU prepolymer with epoxy resin. The effects of content of PU prepolymer and reactive diluter,the diisoeyanate structure etc. on viscosity and adhesion properties of modified epoxy resin were emphatically investigated. The results showed that the viscosity of the modified epoxy resin increased with increasing content of PU prepolymer and decreased with increasing content of reactive diluter. The sequence of viscosity of epoxy resin modified by different diisocyanate was IPDI〉 MDI〉 TDI in the same condition. The shear strength of modified epoxy resin with 20% PU prepolymer on aluminum/aluminum sheets reached 7.82 MPa and the shear strength of modified epoxy resin with 10% PU prepolymer on iron/iron plates reached 11.70 MPa. The adhesion properties of epoxy resin modified with TDI or IPDI on metals were better than that with MDI.