回收聚乙烯的交联发泡及其产品性能研究

Cross-linked foaming process and performance of recycled polyethylene

介绍了以3种回收低密度聚乙烯(PE)为原材料,热膨胀微球为发泡剂,运用模压法加工成型制备得到的交联发泡聚乙烯板材。通过差示扫描量热仪、扫描电子显微镜、摆锤式冲击试验机和电子万能试验机等对所制备交联发泡聚乙烯产品的热学性能、形貌、抗冲击性能和抗拉伸性能进行了表征和分析。结果表明,聚乙烯回收料经加工后,熔点及分子量均有所提升,这归因于过氧化二异丙苯(DCP)的交联作用;交联后形成的网络结构有利于泡孔的稳定,3种回收料交联发泡后均得到了独立分布的泡孔;拉伸强度和冲击强度最高可达9.7 N/mm^(2)和21.5 kJ/m^(2);氧化诱导时间为7.3 min;此发泡材料可望用于生产浮漂和浮力球等各类型水上产品。

A cross-linked foamed polyethylene board was prepared through compression molding using three types of recycled linear low-density polyethylene as raw materials and expandable microspheres as a foaming agent.The thermal properties,morphology,impact resistance and tensile properties of cross-linked foamed polyethylene were characterized using differential scanning calorimeter,scanning electron microscope,film impact tester,and electronic universal testing machine.The experimental results indicated that the melting point and molecular weight of recycled polyethylene materials increased after processing owing to the crosslinking effect of dicumyl peroxide.The network structure formed after crosslinking favored the stability of cells.There were independent cells in the recycled polyethylene after crosslinking and foaming.The foamed materials obtained maximum tensile strength of 9.7 N/mm^(2),impact strength of 21.5 k J/m^(2),and oxidation induction time of 7.3 min,and therefore they could meet the requirement for producing various types of plastic products such as floats and buoyancy balls.