蓖麻油基聚氨酯胶结料与混合料性能研究

Research on the Properties of Castor Oil Based Polyurethane Binder and Mixture

以不同官能度蓖麻油多元醇为软段,制备了相同硬段含量与异氰酸酯指数的聚氨酯胶结料,并进一步与玄武岩集料混合得到聚氨酯混合料,研究了胶结料的表干时间、实干时间、接触角和吸水率以及混合料的马歇尔稳定度、劈裂强度和肯塔堡飞散损失率。结果表明:在硬段含量为45%、异氰酸酯指数为1.05、聚氨酯胶结料含量为6%的条件下,软段蓖麻油多元醇官能度较高时,所得聚氨酯胶结料和混合料的性能更优;当软段蓖麻油多元醇官能度为3.5时,聚氨酯胶结料水接触角为105.8°,平衡吸水率为0.57%,聚氨酯混合料固化60 min时的马歇尔稳定度为12.1 kN,冻融前劈裂强度为4.23 MPa,冻融后劈裂强度为1.98 MPa,标准飞散损失率为2.4%,浸水飞散损失率为4.4%。

Polyurethane binders with the same hard segment content and isocyanate index are prepared using castor oil polyols with different functionalities as soft segments,and polyurethane mixtures are further obtained by mixing the binder and basalt aggregate.The tack-free and curing time,contact angle and water absorption of the binder,as well as the Marshall stability,splitting strength and Contabro loss of the mixture are studied.The results show that under the condition of 45%hard segment content,1.05 isocyanate index,and 6% polyurethane binder content,the higher the functionality of castor oil polyol in soft segment,the better performance of polyurethane binder and mixture.When the functionality of castor oil polyol in the soft segment is 3.5,the water contact angle of polyurethane binder is 105.8°,the equilibrium water absorption is 0.57%,the Marshall stability of polyurethane mixture after curing for 60 min is 12.1 kN,the splitting strength before freeze-thawing is 4.23 MPa,the splitting strength after freeze-thawing is 1.98 MPa,the standard Contabro loss is 2.4%,and the immersion Cantabro loss is 4.4%.