马明兰,马兴元*

Preparation and molecular of two-component microporouspolyurethane elastomers with low viscosity

摘要:

以异佛尔酮二异氰酸酯(IPDI)、聚四氢呋喃二醇(PTMEG)为原料,通过预聚体法合成了端NCO双组份低粘度微孔聚氨酯(LVMPU)预聚体,以1,4-丁二醇(BDO)、三羟甲基丙烷(TMP)为扩链剂,空气中微量水为发泡剂,室温浇注在模具中静置消泡后在高温（130℃）下反应固化得到力学性能、耐黄变、耐光性能优异的双组份低粘度LVMPU弹性体。探讨了不同IPDI:PTMEG质量比、TMP:BDO质量比、剩余NCO含量对双组份低粘度LVMPU弹性体性能的影响。结果表明:当IPDI:PTMEG的质量比小于250:300,剩余NCO含量小于2.4%时,可以得到无NCO的双组份LVMPU弹性体；当IPDI和PTMEG质量比为200:300,TMP:BDO质量比0:1,剩余NCO含量为1.4%时,双组份LVMPU弹性体的力学性能最佳；随着剩余NCO含量的增加,双组份LVMPU弹性体的表面无泡孔结构,截面泡孔逐渐增多,且多为圆形闭孔结构,孔径较大；当TMP:BDO的质量比逐渐增加时,双组份LVMPU弹性体的表面出现大量开孔结构,截面的圆形开孔结构逐渐增多,孔径分布较为均匀,平均孔径降低。

Abstract:

Therefore, NCO-terminated two-component microporous polyurethane elastomers with low viscosity (LVMPU) prepolymer was synthesized by prepolymer method using isophorone diisocyanate (IPDI) and polytetramethylene ether glycol (PTMEG) as raw materials. Secondly, 1,4-butanediol (BDO) and trimethylolpropane (TMP) were used as chain extenders, and a small amount of water in the air was used as foaming agent, two-component LVMPU has excellent mechanical properties, yellowing resistance, and light resistance was obtained by reaction curing at high temperature(130℃) after static defoaming at room temperature in the mold. The effects of different mass ratio of IPDI and PTMEG, TMP and BDO and residual NCO content on the properties of two-component LVMPU was investigated. The results show that when the mass ratio of IPDI and PTMEG is less than 250:300 and the residual NCO content is less than 2.4%, two-component LVMPU elastomer without NCO groups can be obtained; When the mass ratio of IPDI and PTMEG is 200:300, the mass ratio of TMP and BDO is 0:1, and the residual NCO content is 1.4%, the mechanical properties of the two-component LVMPU elastomer are the best; With the increase of the residual NCO content, the surface of the two-component LVMPU has no cell structure, and the cross-sectional cells increase gradually, and most of them are circular closed-cell structures with large pore sizes; When the mass ratio of TMP and BDO increases gradually, most of open-cell structures appear on the surface of the two-component LVMPU, the circular open-cell structures of the section increase gradually, the pore size distribution is relatively uniform, and the average pore size decreases.