乙丙橡胶／聚丙烯共混型热塑性弹性体的流变行为

A Study on Rheological Behavior of EPDM/PP Thermoplastic Elastomers

用恒负荷式毛细管流变仪研究已丙橡胶（ＥＰＤＭ）／聚丙烯（ＰＰ）简单共混型聚烯烃热塑性弹性体（ＴＰＯ）的流变性能，讨论了ＴＰＯ的橡塑比、软化剂、加工助剂等配方因素及温度和剪切速率（或剪切应力）等工艺条件对其流变行为的影响．结果表明，部分结晶性ＥＰＤＭ与ＰＰ共混物的表观粘度与组成物粘度的关系服从对数加和法则，增大剪切速率能显著降低共混物的表现粘度，温度对共混物表现粘度的影响较小．软化剂能显著降低共混物的表现粘度，在同一剪切速率下，共混物表观粘度的对数值与软化剂含量成线性关系．少量适当的加工助剂也能显著降低共混物的表观粘度，而且对共混物的力学性能无显著影响．

The rheological behavior of crystalline ethylene-propylenediene terpolymer (EPDM)/polypropylene (PP) thermoplastic elastomers (TPO) has been studied with capillary viscometer of constant stress type. The effect of formulation factors and processing conditions on the apparent viscosity of TPO is discussed. The results show,the relationship between the apparent viscosities of TPO and that of the component polymers at given shear rates follows the logarithmic additiyity rule,increasing shear rate results in significant decrease of the apparent viscosity of TPO,the temperature has slight effect on the apparent viscosity. Softener can lower the apparent viscosity of TPO to a great extent,and the logarithm of the apparent viscosity stays in a straight line related to the content of softener. A small amount of proper processing aids can also remarkably improve the fluidity of TPO without a fall of the mechanical properties.