NCO含量对PTMG体系聚氨酯弹性体的影响

Effect of NCO Contents on Polyurethane Elastomer of PTMG System

以聚四亚甲基醚二醇-二苯基甲烷二异氰酸酯-1,4-丁二醇(PTMG-MDI-BDO)为基础体系,采用预聚体法,合成了异氰酸酯基(NCO)含量6%-9%的聚氨酯弹性体。通过改变预聚体中NCO含量,探究了其对制备的PTMG体系的聚氨酯弹性体综合性能的影响。结果表明,随着NCO含量的增加,材料的交联密度、硬度、拉伸强度、300%定伸应力和撕裂强度均呈现增加的趋势,且材料的耐磨性能变好,而其扯断伸长率和回弹性均下降,压缩永久变形率降低。NCO含量越高,材料的玻璃化转变温度升高,耐低温性能变差。

Polyurethane elastomer with isocyanate group(NCO)contents of 6%-9%was synthesized by prepolymer method based on polytetramethylene ether glycol-diphenylmethane diisocyanate-1,4-butanediol(PTMG-MDI-BDO).By changing NCO contents in prepolymer,the influence of NCO contents on the comprehensive properties of polyurethane elastomer in PTMG system was investigated.The results show that with the increase of NCO contents,the crosslinking density,hardness,tensile strength,stress at 300%elongation and tear strength of the material all show an increasing trend,and the wear resistance of the material becomes better,while the elongation at break and resilience of the material decrease,and the compression set rate decreases.The isocyanate group contents are higher,the glass transition temperature T g of the material is higher,and the low temperature resistance is worse.