The preparation of expended polypropylene (EPP) by a bead foam processing is of great significance for their potential applications, but the development of a facile method adopting the actual manufacturing process remains a great challenge. In this study, a new bead foam processing based on the actual manufacturing process was successfully developed to produce high quality EPP. Suitable processing conditions as well as the effect of the precursor sample properties associated with expanded polypropylene (EPP) manufactured by the bead foam process were investigated. The elongational viscosity was firstly measured using polypropylene (PP) samples with different crystallinities and molecular weights in order to investigate the relevant foaming temperatures. The crystallinity and molecular weight of each sample were controlled by the addition of comonomer, and the melting behavior and cell morphology of the foamed specimens were analyzed utilizing a pilot-scale foaming experiment. Based on our results and observations, a plausible mechanism for formation of high quality EPP was proposed. This work offers a new method for fabricating EPP with a high quality by the bead foam processing. It also provides important information about how the morphology and cell numbers of EPP may be finely controlled by the processing conditions.

中文翻译：

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结晶度和分子量对发泡珠生产中发泡聚丙烯熔融行为和细胞形态的影响

通过珠粒泡沫加工制备消耗性聚丙烯（EPP）对于它们的潜在应用具有重要意义，但是采用实际制造工艺开发一种简便的方法仍然是一个巨大的挑战。在这项研究中，成功​​开发了一种基于实际制造工艺的新型珠粒泡沫加工工艺，以生产高质量的EPP。研究了合适的加工条件以及与通过珠粒泡沫工艺制造的膨化聚丙烯（EPP）相关的前体样品性能的影响。首先使用具有不同结晶度和分子量的聚丙烯（PP）样品测量伸长粘度，以研究相关的发泡温度。通过加入共聚单体控制每个样品的结晶度和分子量，并使用中试规模的发泡实验分析发泡样品的熔融行为和泡孔形态。根据我们的结果和观察，提出了形成高质量EPP的合理机制。这项工作提供了一种通过珠粒泡沫加工来制造高质量EPP的新方法。它还提供了有关如何通过加工条件精细控制EPP的形态和细胞数量的重要信息。这项工作提供了一种通过珠粒泡沫加工来制造高质量EPP的新方法。它还提供了有关如何通过加工条件精细控制EPP的形态和细胞数量的重要信息。这项工作提供了一种通过珠粒泡沫加工来制造高质量EPP的新方法。它还提供了有关如何通过加工条件精细控制EPP的形态和细胞数量的重要信息。