硫化体系对混炼型聚氨酯弹性体性能的影响

Effect of Vulcanization Systems on Properties of Millable Polyurethane Elastomer

以聚醚多元醇和二苯基甲烷二异氰酸酯为单体,α-烯丙基甘油醚为扩链剂合成了混炼型聚氨酯(MPU)弹性体,研究硫黄硫化体系和过氧化物[过氧化二异丙苯(DCP)]硫化体系对MPU胶料性能的影响。结果表明:随着硫黄和DCP用量的增大,MPU胶料的t90略微延长,硫黄硫化体系的MPU胶料的t90短于DCP硫化体系的MPU胶料;随着硫黄和DCP用量的增大,硫黄硫化体系和过氧化物硫化体系的MPU硫化胶的100%定伸应力增大,拉伸强度先增大后减小,拉断伸长率减小;与DCP硫化体系的MPU硫化胶相比,硫黄硫化体系的MPU硫化胶的拉伸强度和拉断伸长率较大,综合拉伸性能较好;DCP硫化体系的MPU硫化胶的交联密度远大于硫黄硫化体系的MPU硫化胶;当硫黄用量超过1.5份时,MPU硫化胶出现喷霜现象。

In this study,millable polyurethane(MPU)elastomer was synthesized by using polyether polyol and diphenylmethane diisocyanate as monomers andα-allyl glycerol ether as the chain extender,and the effects of sulfur vulcanization system and peroxide[dicumyl peroxide(DCP)]vulcanization system on the properties of the MPU compounds were investigated.The results showed that,with the increase of the amount of sulfur and DCP,the t90 of the MPU compounds were prolonged,and the t90 of the MPU compound with sulfur vulcanization system was shorter than that of the MPU compound with DCP vulcanization system.Furthermore,the tensile stresses at 100%elongation of the MPU vulcanizates increased with the increase of the amounts of the sulfur and DCP,the tensile strengths first increased and then decreased,and the elongations at break decreased.Compared with the MPU vulcanizate with DCP vulcanization system,the MPU vulcanizate with sulfur vulcanization system had higher tensile strength and larger elongation at break,and its comprehensive tensile properties were better.Moreover,the crosslinking density of the MPU vulcanizate with DCP vulcanization system was much higher than that of the MPU vulcanizate with sulfur vulcanization system.When the sulfur amount exceeded 1.5 phr,a blooming phenomenon would appear on the surface of the MPU vulcanizate.