废聚酯醇解制备聚氨酯胶粘剂的研究

以聚醚多元醇(PPG)和4,4′-二苯基甲烷二异氰酸酯(MDI-100LL)为原料制备了含有-NCO的聚氨酯(PU)胶粘剂的A组分,将废聚酯(PET)通过醇解、酯化和缩聚等步骤制得含有-OH的PU胶粘剂的B组分,讨论了反应条件对A组分和B组分性能的影响。结果表明:制备A组分时,反应温度80℃,反应时间3 h;制备B组分时,废PET醇解温度195～210℃(反应时间3.5 h),酯化温度140～150℃(反应时间60 min),缩聚温度190～210℃(反应时间30 min)。调节双组分的配比,可以制备出满足不同施工要求的胶粘剂,当n(A组分)∶n(B组分)=1.30∶1时,胶粘剂的粘接效果最佳;固化后PU胶膜的玻璃化转变温度(Tg)达到-31℃。

Study on preparing polyurethane adhesive with alcoholysis waste PET as main raw material

The component A containing-NCO in polyurethane(PU) adhesive was synthesized with polyether polyol(PPG) and 4,4′-diphenylmethane diisocyanate(MDI-100LL) as raw materials.The component B containing -OH in PU adhesive was prepared by alcoholysis,esterification and polycondensation of waste PET(polyethylene terephthalate).The PU adhesive was prepared by mixing component A and B.The influences of reaction conditions on properties of component A and B were discussed.The results showed that the preparing condition of component A was polymerization at 80 ℃ for 3 h.The preparing conditions of component B were waste PET alcoholysis at 195-210 ℃ for 3.5 h,waste PET esterification at 140-150 ℃ for 60 min,waste PET polycondensation at 190-210 ℃ for 30 min.The PU adhesives,which was made by adjusting molar ratio of n(A component)∶n(B component),can meet requirements of different operation.The PU adhesives had optimal bonding effect when molar ratio of n(A component)∶n(B component) was 1.30∶1,its glass transition temperature was-31 ℃.