环氧改性的水性聚氨酯合成及其性能研究

Modification and properties of waterborne polyurethane by epoxy

利用废弃PET降解所得的原料制备的水性聚氨酯,通过环氧树脂E-44进行了改性,所得聚氨酯的耐水性、力学和热学等综合性能优良。结果表明：E-44在扩链阶段加入,加入量为w（E-44）=6%～8%时,制得的乳液平均粒径为50 nm,黏度为44 m Pa·s,胶膜拉伸强度为6.4 MPa,24 h吸水率降低至7%,铅笔硬度为3H,附着力为1级。环氧改性聚氨酯乳液外观好且贮存稳定,黏度适中。

In order to improve the performance of waterborne polyurethane from waste PET degrada- tion,epoxy resin E-44 was used to prepare waterborne epoxy-modified polyurethane（PUE）.The influ- ence of adding modality and dosage of E-44 on the performance of modified waterborne polyurethane was discussed.The results showed that water resistance,hardness and tensile strength of the film were significantly improved after it was modified by E-44. Epoxy resin was added at the chain extension stage,the appropriate amount was 6% to 8%.Under the optimum condition,the average particle size of PUE emulsion was 50nm, the viscosity was 44 mPa ; s; the tensile strength of PUE film was 6.4 MPa,water absorption（24h） decreased to 7% ,the pencil, hardness was 3H and adhesion was I grade. Epoxy-modified polyurethane emulsion showed good appearance, storage stability and moderate vis- cosity, the mechanical strength and thermal stability of the film were improved significantly.