混炼型聚氨酯橡胶/乙丙橡胶硫化胶交联密度与应力-应变关系的拟合和预测

Fitting and Prediction of the Relationship Between Crosslinking Density and Stress-Strain of MPU/EPDM Blending Rubber

研究了硫化橡胶的应力-应变关系与交联密度之间的定量关系,建立了其拟合模型,发现了单一组分的交联网络对共混胶整体应力-应变关系的影响规律,并且将模型计算所得的结果与实测结果进行了对比验证,证明了模型可行.研究以混炼型聚氨酯橡胶(MPU)/乙丙橡胶(EPDM)共混胶为例,借助平衡溶胀法测定共混胶的两相交联密度.首先,通过纯MPU和纯EPDM自身交联密度和定伸应力的数据拟合得到二者的线性关系方程,然后,运用该线性关系方程和MPU/EPDM共混胶的两相交联密度进行计算,得到共混胶各相的预测定伸应力,最后将各相所得的预测定伸应力按共混配比进行计算,即为预测的共混胶整体定伸应力,进而得到应力-应变关系.

In this paper,the fitting model of modulus and the molecular network of rubber was established,and the influence of the single component molecular network on the overall constant elongation stress of the blend was found.The results of the fitting model were com-pared with the experimental results,which proved that the model was feasible.Taking mill-able polyurethane rubber(MPU)/ethylene propylene rubber(EPDM)blend as an example,the two-phase crosslinking density of the blend was determined by equilibrium swelling method.First,the linear relationship between MPU and EPDM was obtained by fitting the data of crosslinking density and constant elongation stress.Then,the constant elongation stress of single component of MPU/EPDM blend was calculated by using the linear relation-ship and the two-phase crosslinking density of MPU/EPDM blend.The constant elongation stress of each component was added according to the blending ratio,which was the predicted constant elongation stress of the blend.