Supercritical CO2 foaming and mechanical properties of thermoplastic polyurethane based on molecular structure

IF 3.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids Pub Date : 2025-02-06 DOI:10.1016/j.supflu.2025.106541

Chenyang Niu, Xiulu Gao, Yichong Chen, Weizhen Sun, Ling Zhao, Dongdong Hu

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Abstract

The molecular structures of thermoplastic polyurethane (TPU) affect its microphase separation and foaming behavior. Three aliphatic TPUs were studied to investigate the influence of their molecular structures on their crystallization behavior, shear rheological properties, mechanical properties, and foaming behavior. The experimental results indicated that the branched structure and hard segment content affected the crystallization behavior of TPU. Lower crystallinity decreased the foaming initiation temperature, whereas higher crystallinity enhanced the stability of cell structure. The branched structure and hard segment domains functioned as heterogeneous nucleation sites, leading to increased cell density and reduced cell size in microcellular TPU. Microcellular TPU with a high molecular weight and branched structure exhibited superior tensile strength and elongation at break, i.e., the tensile strength and elongation at break of TPU1 with a density of 0.25 g/cm³ reached 10.82 MPa and 373 %, respectively. This study demonstrated the regulation of microcellular TPU by analyzing its molecular structures.

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基于分子结构的热塑性聚氨酯超临界CO2发泡及力学性能研究

热塑性聚氨酯（TPU）的分子结构影响其微相分离和发泡性能。研究了三种脂肪族tpu的分子结构对其结晶性能、剪切流变性能、力学性能和发泡性能的影响。实验结果表明，支链结构和硬段含量影响TPU的结晶行为。较低的结晶度降低了泡沫的起泡温度，而较高的结晶度提高了细胞结构的稳定性。微细胞TPU的分支结构和硬段结构域作为异质成核位点，导致细胞密度增加和细胞尺寸减小。具有高分子量和支链结构的微孔TPU具有优异的抗拉强度和断裂伸长率，即密度为0.25 g/cm3的TPU1的抗拉强度和断裂伸长率分别达到10.82 MPa和373% %。本研究通过分析微细胞TPU的分子结构，证实了TPU对微细胞的调控作用。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Supercritical Fluids 工程技术-工程：化工

CiteScore

7.60

自引率

10.30%

发文量

236

审稿时长

56 days

期刊介绍： The Journal of Supercritical Fluids is an international journal devoted to the fundamental and applied aspects of supercritical fluids and processes. Its aim is to provide a focused platform for academic and industrial researchers to report their findings and to have ready access to the advances in this rapidly growing field. Its coverage is multidisciplinary and includes both basic and applied topics. Thermodynamics and phase equilibria, reaction kinetics and rate processes, thermal and transport properties, and all topics related to processing such as separations (extraction, fractionation, purification, chromatography) nucleation and impregnation are within the scope. Accounts of specific engineering applications such as those encountered in food, fuel, natural products, minerals, pharmaceuticals and polymer industries are included. Topics related to high pressure equipment design, analytical techniques, sensors, and process control methodologies are also within the scope of the journal.