有机硅改性纳米凝胶降低光聚合体系的收缩应力

Shrinkage stress reduction in photopolymerization by polysiloxane-modified nanogel

采用硫醇为链转移剂,以甲基丙烯酸酯改性硅油,二脲烷二甲基丙烯酸酯和甲基丙烯酸异冰片酯为主要原料,合成了一种可聚合型有机硅改性纳米凝胶。研究了纳米凝胶的加入量对三乙二醇二甲基丙烯酸酯光聚合体系的聚合动力学、收缩应力、弯曲强度、弯曲模量及热稳定性的影响。结果表明,有机硅的添加,能够使三乙二醇二甲基丙烯酸酯光固化体系延迟凝胶,有效降低收缩应力。有机硅的加入也能提高聚合物的热稳定性,并且其添加质量分数在不大于20%时不影响聚合物的机械性能。

A polymerizable nanogel was synthesized with methacrylate-modified polysiloxane, urethane dimethacrylate and isobornyl methacrylate as main raw materials in the presence of a thiol chain transfer agent. The kinetics of photopolymerization, shrinkage stress, mechanical properties and thermostability of UV-cured materials with different contents of nanogel were investigated. The results indicated that the addition of nanogel could delay the onset of stress and further reduce the overall photopolymerization stress without compromising the mechanical properties of the resulting polymers, when the added mass fraction was within 20%. Moreover, with the addition of nanogel, the thermostability of the resulting polymer was strengthened.