异氰酸酯指数对潜固化型单组分聚脲性能的影响

Influences of isocyanate index on properties of latent curing single-component polyurea

以聚四氢呋喃二醇、甲苯二异氰酸酯和 唑烷潜固化剂为原料制备单组分聚脲。并通过FT-IR、热失重、吸水率、力学性能、硬度、表干时间和实干时间等表征手段研究了异氰酸酯指数(R值)对单组分聚脲结构与性能的影响。结果表明,随着R值的增加,单组分聚脲的耐热性能、表干时间、实干时间和硬度逐渐增加,吸水率先降低后增加,力学性能先增加后降低。当R值为0.95时,单组分聚脲的综合性能达到最优。

One-component polyurea is synthesized by using polyoxytertramethylene glycol,toluene diisocyanate and oxazolidine latent curing agent as raw materials. The effects of isocyanate index(R value) on the structure and performance of this one-component polyurea are evaluated through FT-IR,thermogravimetric analysis,water absorption,mechanical properties,hardness,surface drying time and dry time. It is shown that as R value increases,the heat resistance,surface drying time,drying time and hardness of this one-component polyurea increase gradually,while its water absorption rate declines at first and increases then,its mechanical property increases at first and declines then.Onecomponent polyurea shows the best overall performance when R value is 0. 95.