Jin Guangzhi, Gong Yuzhen, Wang Jun, Wang Min, Wang Jiadong, Wang Runguo, Qin Xuan, Lu Yonglai
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China.
Engineering Research Center of Elastomer Materials Energy Conservation and Resources, Ministry of Education, Beijing 100029, China.
Langmuir. 2024 Nov 12;40(45):23939-23950. doi: 10.1021/acs.langmuir.4c03093. Epub 2024 Nov 1.
Thermoplastic polyurethane (TPU) is essential in resource exploration, healthcare, automotive, and high-end recreational sports. Despite extensive research on TPU's microstructures and their macroscopic properties, the impact of processing conditions like compression and injection molding remains underexplored. This study investigates the influence of processing conditions on TPU by preparing samples with varying hard segment contents using compression molding at 205 °C and injection molding at melt temperatures of 205, 210, 215, and 220 °C, followed by heat treatment at 120 °C for 12 h. Results indicate that injection-molded TPU at 205 °C exhibits lower hydrogen bonding, crystallinity, long period, interfacial thickness, and lamella thickness than compression-molded TPU, leading to higher Young's modulus but lower elongation at break. As melt temperatures increase, these microstructural parameters decrease, reducing Young's modulus and increasing elongation at break. Post heat treatment, microstructural parameters increase, aligning Young's modulus with that of compression-molded samples, while elongation at break surpasses them. This suggests that heat treatment enhances microphase separation by rearranging hard and soft segments. our research reveals a consistent pattern across TPUs with varying hard segment contents, indicating that adjusting processing parameters can effectively regulate microstructure and performance, offering valuable insights for developing high-performance polyurethanes.
热塑性聚氨酯（TPU）在资源勘探、医疗保健、汽车和高端休闲运动领域至关重要。尽管对TPU的微观结构及其宏观性能进行了广泛研究，但诸如压缩成型和注塑成型等加工条件的影响仍未得到充分探索。本研究通过在205°C下进行压缩成型以及在205、210、215和220°C的熔体温度下进行注塑成型来制备具有不同硬段含量的样品，随后在120°C下进行12小时的热处理，以此研究加工条件对TPU的影响。结果表明，在205°C下注塑成型的TPU与压缩成型的TPU相比，具有更低的氢键、结晶度、长周期、界面厚度和片晶厚度，导致其杨氏模量更高但断裂伸长率更低。随着熔体温度升高，这些微观结构参数降低，杨氏模量减小而断裂伸长率增加。经过热处理后，微观结构参数增加，使杨氏模量与压缩成型样品的杨氏模量一致，而断裂伸长率超过了它们。这表明热处理通过重新排列硬段和软段来增强微相分离。我们的研究揭示了不同硬段含量的TPU之间的一致模式，表明调整加工参数可以有效调节微观结构和性能，为开发高性能聚氨酯提供了有价值的见解。
