Mei Xianzhu, Do Quoc-Viet, Narita Takaaki, Yamaguchi Misaki, Yamaguchi Masayuki
Materials Chemistry Frontiers Research Area, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi 923-1292, Ishikawa, Japan.
Performance Additives Group, C&A Hiroshima, Coating & Additives R&D Center, Mitsubishi Chemical Corporation, 20-1 Miyukicho, Otake 739-0693, Hiroshima, Japan.
Molecules. 2024 Aug 6;29(16):3730. doi: 10.3390/molecules29163730.
The rheological properties of a polyamide (PA) resin with low crystallinity were modified by melt-mixing it with a small amount of an alternative -olefin-maleic anhydride copolymer as a reactive compound. Because PA has a low melting point, rheological characterization was performed over a wide temperature range. Owing to the reaction between PA and the alternative -olefin-maleic anhydride copolymer, the blend sample behaved as a long-chain branched polymer in the molten state. The thermo-rheological complexity was obvious owing to large flow activation energy values in the low modulus region, i.e., the rheological time-temperature superposition principle was not applicable. The primary normal stress difference under steady shear was greatly increased in the wide shear rate range, leading to a large swell ratio at the capillary extrusion. Furthermore, strain hardening in the transient elongational viscosity, which is responsible for favorable processability, was clear. Because this is a simple modification method, it will be widely employed to modify the rheological properties of various polyamide resins.
通过将少量作为反应性化合物的替代烯烃-马来酸酐共聚物与低结晶度聚酰胺（PA）树脂进行熔融共混，对其流变性能进行了改性。由于PA熔点较低，因此在较宽的温度范围内进行了流变表征。由于PA与替代烯烃-马来酸酐共聚物之间的反应，共混样品在熔融状态下表现为长链支化聚合物。由于低模量区域的流动活化能值较大，热流变复杂性明显，即流变时间-温度叠加原理不适用。在较宽的剪切速率范围内，稳态剪切下的第一法向应力差大幅增加，导致毛细管挤出时的膨胀比增大。此外，负责良好加工性能的瞬态拉伸粘度中的应变硬化很明显。由于这是一种简单的改性方法，它将被广泛用于改性各种聚酰胺树脂的流变性能。
