聚(苯乙烯-二乙烯基苯)/聚氨酯浇注胶的研制

On Less Viscous and Inexpensive CPUR

采用苯乙烯、二乙烯基苯对聚氨酯进行了改性研究，利用一步法工艺，制备了与三元乙丙橡胶具有化良粘接性能的双组分室温固化的改性浇注胶，克服了预聚法工艺所存在的合成工艺较长、固化工艺复杂、设备要求较高等缺点。通过正交实验确定了最优配方，并对最佳体系的主要力学性能与ABS和三元乙丙橡胶的粘接性能等进行了测试分析。结果表明，控制-NCO／-OH比值、低分子二元醇与聚酯多元醇的-OH摩尔比、催化引发体系用量等，可得到综合性能优异的稳定体系。当R=1．10、a=0．5、BPO／St=0．02、β=0．04％、γ=30％、ε=4％的力学性能均轶佳；改性剂、交联剂的用量对体系的粘接性能影响较大。该双组分浇注胶与三元乙丙橡胶/ABS的拉伸剪切强度可达15．0 MPa，粘接机理与传统的扩散机理、配位键理论等有所不同，主要遵循共轭互穿网络粘接理论。

Abstract: A factory in Hangzhou, Zhejing, P. R. C. is in urgent need of good-quality CPUR (casting polyurethane rubber) that is as low in viscosity as but far less expensive than imported CPUR. In order to reduce the viscosity of and improve the properties of existing Chinese CPUR, we modify it with a poly (styrene-co-benzene) especially developed by us for this purpose. The results, as presented in Tables 3 and 5 and Fig. 1, show preliminarily that the initiator BPO, accelerator DMA, dibutyltin dilaurate β, the ratio R=-NCO/-OH, the molar rate of hydroxyl of binary alcohol and polyols a, the ratio ε=DVB/St, the ratio γ=St/(PU+St), the ratio δ=BPO/St and the ratio θ=DMA/BPO affect mechanical properties. The study of the results leads us to the preliminary conclusion that the best combination of mechanical properties can be realized when R=1. 10, a=0. 50, δ=2. 0%, ε=4%, β=0. 04%, γ=30% and θ=1/3. Besides we reduce the cost of our less viscous and inexpensive CPUR by using one-step process and curing at room temperature.