丙烯酸异冰片酯改性水性聚氨酯的合成及其表征

Synthesis and Characterization of Isobornyl Acrylate Modified Waterborne Polyurethane

通过乳液聚合法制备了丙烯酸异冰片酯(IBOA)改性水性聚氨酯(WPU)复合乳液,考察了引发剂用量、反应温度、IBOA/WPU质量比及保温时间对单体转化率、胶膜吸水率及拉伸强度的影响,同时采用正交试验对工艺条件进行了优化。研究结果表明,较适宜的反应条件为IBOA与WPU固体组分质量比为1∶3,引发剂过硫酸铵(APS)用量为IBOA单体添加量的0.5%,反应温度80℃,保温熟化3 h。利用傅立叶变换红外光谱、透射电子显微镜、热重分析等测试方法对复合材料的性能进行了表征,并探讨了性能与结构的关系,结果显示单体的平均转化率达97.35%,改性水性聚氨酯的吸水率达到5.94%,拉伸强度达到27.17 MPa。制备的乳液为核壳结构,乳液稳定性良好;胶膜发生的热降解分别由硬段降解和软段降解造成。

The composite emulsion of waterborne polyurethane （WPU） modified by isobornyl acrylate （IBOA） was prepared by emulsion polymerization method. The effects of the dosage of initiator, mass ratio of IBOA to WPU, reaction temperature and holding time on the mass ratio of solid content, monomer conversion rate, water absorption and tensile strength of film were investigated. The optimum conditions were obtained by orthogonal test. Eventually, it was determined that the best preparation conditions of WPU modified by acrylate （WPUA） were ： m （IBOA） ： m （WPU） = 1 ： 3,0.5 % APS as the initiator （ based on the mass of monomer）, reaction temperature 80 ℃ and holding time 3 h. The chemical structure, mechanical property, water resistance, and other properties of the composite were characterized by FT-IR, TEM and TG, respectively. The structureproperty relationship was also discussed. It showed that the average monomer conversion was 97.35%, the average water absorption of WPU modified by IBOA was 5.94 %, and its average tensile strength was 27.17 MPa. Moreover, the morphology of emulsion was core-shell structure, and its stability was good. Thermal degradation of the film was caused by two stages including hard segments degradation and soft segments degradation, respectively.