Melt Rheology of Polypropylene Containing Small Amounts of High-Molecular-Weight Chain. 2. Uniaxial and Biaxial Extensional Flow
Melt Rheology of Polypropylene Containing Small Amounts of High-Molecular-Weight Chain. 2. Uniaxial and Biaxial Extensional Flow
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DOI：
10.1021/ma0015525
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发表时间：
2001-07
期刊：
影响因子：
5.5
通讯作者：
M. Sugimoto;Yuichi Masubuchi;J. Takimoto;K. Koyama
中科院分区：
文献类型：
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作者：
M. Sugimoto;Yuichi Masubuchi;J. Takimoto;K. Koyama
采用Meissner型流变仪，在恒定拉伸应变速率下，对高熔体强度聚丙烯在瞬态拉伸流动条件下的单轴拉伸流动行为进行了研究。采用润滑挤压流动法测定了高熔体强度聚丙烯在恒应变速率下的等双轴拉伸流动行为。高熔体强度聚丙烯由作为主要组分的聚丙烯（PP）和作为长松弛时间组分的高分子量聚乙烯（PE）组分组成（参见第1部分）。通常认为该体系是不混溶的体系，至少在静止状态下是这样。然而，在第一部分中，我们发现含有非常高分子量PE的高熔体强度PP显示出与常规PP明显不同的剪切流动行为，例如，高弹性和两步粘度在低剪切速率和强和弱的应变相关的非线性阻尼功能，表征快速和缓慢的松弛过程。在这项研究中，Tra.
Uniaxial extensional flow behavior was measured for the high-melt-strength polypropylene using a Meissner-type rheometer under transient extensional flow with constant tensile strain rate. The equibiaxial extensional flow behavior of the high-melt-strength polypropylene was measured via the lubricated squeezing flow method under constant strain rate. The high-melt-strength polypropylene consists of polypropylene (PP) as a main component and high-molecular-weight polyethylene (PE) component as a long relaxation time component (see part 1). This system is generally believed to be an immiscible system, at least under the quiescent state. Nevertheless, in part 1, we have found that the high-melt-strength PP with very high-molecular-weight PE shows distinctly different shear flow behaviors from conventional PP, e.g., high elasticity and two-step viscosity at low shear rates and strong and weak strain-dependent nonlinear damping functions characterizing fast and slow relaxation processes. In this study, the tra...