In this study, the crosslinked ethylene–propylene–diene monomer (EPDM) foams were prepared by batch foaming using compressed CO₂ as the blowing agent. The various crosslinking structures, i.e., the local primary crosslinking structure, the micro-crosslinking structure, and the full crosslinking structure, were generated by adjusting the loading of the crosslinking agent. The models were established to illustrate the fundamental influences of crosslinking structures on the evolution of cell morphology. EPDM-0.2B with 0.2 parts per hundred of rubber (phr) loading of the crosslinking agent had the micro-crosslinking structure, which improved the foamability of EPDM significantly. The foaming temperature window was broadened from 40–80 to 100–200 °C, and the expansion ratio was increased from 5.6 to 7.1 compared with pure EPDM. Meanwhile, the structure endows the EPDM-0.2B foam with improved creep resistance, increased thermal stability, and a melt-recycling ability. The EPDM foam with the full crosslinking structure exhibited better creep resistance and thermal stability, but the structure spoiled its melt-recycling ability significantly.

中文翻译：

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交联结构对压缩CO ₂吹制的微孔EPDM泡沫的细胞形态，蠕变性能，热性能和再循环行为的基本影响

在这项研究中，交联的乙烯-丙烯-二烯单体（EPDM）泡沫是通过使用压缩CO ₂分批发泡制备的作为发泡剂。通过调节交联剂的负载量，产生了各种交联结构，即局部的一次交联结构，微交联结构和全交联结构。建立模型以说明交联结构对细胞形态演变的基本影响。每百份橡胶中添加0.2份（phr）交联剂的EPDM-0.2B具有微交联结构，从而显着提高了EPDM的发泡性。与纯EPDM相比，起泡温度范围从40–80°C扩大到100–200°C，膨胀比从5.6增加到7.1。同时，该结构使EPDM-0.2B泡沫具有改善的抗蠕变性，增强的热稳定性和熔体再循环能力。