超支化聚氨酯丙烯酸酯的合成及其固化膜性能

以合成的甲苯-2,4-二异氰酸酯.丙烯酸羟丙酯(TDI.HPA)单体对超支化聚酯(HBPE)进行端羟基改性,得到超支化聚氨酯丙烯酸酯(HBPUA)。研究了反应温度、时间对产物游离—NCO含量的影响,通过摆杆硬度、附着力、柔韧性、冲击强度等测试研究了活性单体的种类及用量对固化膜性能的影响,并采用FT-IR及TG对HBPE,HBPUA及其固化膜进行了表征和分析。结果表明,合成HBPUA的最佳条件为:n(2,4-TDI):n(HPA):n(HBPE)=6:6:1,反应温度70℃,反应时间3 h,催化剂二月桂酸丁基锡(DBTDL)用量为总质量的0.6%;TDI.HPA的合成反应温度35℃,反应时间2.5 h,DBTDL用量为总质量的0.4%。采用己二醇二丙烯酸酯为活性单体并控制其质量分数为20%时,超支化聚氨酯丙烯酸酯涂膜的力学性能、热稳定性较好。

Synthesis of hyperbranched polyurethane acrylates and properties of their cured films

The hyperbranched polyurethane acrylates(HBPUA)were prepared by terminal hydroxyl modification of hyperbranched polyester using synthesized 2,4-toluene diisocyanate hydroxypropyl acrylate(TDI·HPA)monomers.The effect of reaction temperature and time on the free-NCO contents of the products were studied.The active monomer kinds and amounts on the properties of UV cured film were investigated by the testings of pendulum hardness,adhesion,toughness and impact strength.The HBPE,HBPUA and its cured film were characterize and analyzed by FT-IR and TG.The result showed that the best synthesis conditions of HBPUA were as followed:n(2,4-TDI)∶ n(HPA)∶ n(HBPE)=6∶ 6∶ 1,rection temperature 70 ℃,reaction time 3 h,catalyst dilaurate tributyltin(DBTDL)amount 0.6%(based on the total mass).The synthesis conditions of TDI · HPA were as followed:reaction tempetature 35 ℃,reaction time 2.5 h,DBTDL amount 0.4%.The mechanical properties and thermal stability of coating films were better using hexanediol diacrylate as active monomer and mass fraction of 20%.