交联密度对脂肪族聚氨酯弹性体结构与性能的影响

采用异佛尔酮二异氰酸酯(IPDI)与聚醚二元醇、三羟甲基丙烷(TMP)和1,4-丁二醇反应制备了具有不同交联密度的脂肪族聚氨酯弹性体.研究结果表明,当聚氨酯弹性体的硬段含量为40 wt%时,随着TMP含量的增加,聚氨酯弹性体的交联密度线性增加.随着聚氨酯弹性体交联密度的提高,聚氨酯中硬段相的玻璃化转变温度由32℃降为2...

EFFECT OF CROSSLINK DENSITY ON THE STRUCTURES AND PROPERTIES OF ALIPHATIC POLYURETHANE ELASTOMER

A series of crosslinked aliphatic polyurethane(PU) elastomers with various crossslink densities were synthesized by the reaction of isophorone diisocyanate(IPDI) with polyether diol,trimethylolpropane(TMP) and 1,4-butanediol(BDO) through one step method.The results showed that the crosslink density of PU elastomers exhibited a linear relationship to the content of TMP,while the content of hard segments of PU elastomers was fixed at 40 wt%.With the increase of the crosslink density of the PU elastomers,the glass transition temperature(Tg) value of the hard segment domains in the PU dropped significantly from 32℃ to 21℃,the Tg value of the soft segment domains in the PU dropped slightly form-47℃ to-48℃,and the degree of H-bonded urethane carbonyl in the PU decreased from 83% to 63%,which indicated that the micro-phase miscibility of the PU elastomers was enhanced.With the increase of the crosslink density of the PU elastomers,the TGA results showed that the onset decomposition and the maximum decomposition temperature of the PU elastomers increased from 285℃ to 319℃ and 325℃ to 349℃ respectively,which indicated that the thermal stability of the PU elastomers was also improved.The mechanical test indicated that the Young’s modulus,modulus at 100% extension and Shore A hardness of the PU elastomers significantly increased with the increase of the crosslink density of PU,while the elongation at break decreased.