同质异构交联法对再生聚乙烯的改性研究

通过硅烷交联法制备了交联聚乙烯（PE），并将其加入到水选废旧塑料薄膜再生PE颗粒中进行改性研究。通过扫描电子显微镜（SEM）对再生料冲击样条的断口进行观察，研究了交联料用量对再生PE的力学性能和加工流动性的影响；用差示扫描量热法（DSC）和X射线衍射法(XRD)研究了当交联料添加量为15份时，再生料结晶性能与交联度的关系。结果表明，添加了交联料的再生料的聚集态结构发生了变化，形成了“同质异构分散结构”，该结构会使再生料的拉伸强度和冲击强度大幅提升，而断裂伸长率和熔体流动速率则有一定程度的下降；当交联料的添加量为15份时,材料具有最佳的综合性能，且当添加量为15份、交联度为33.5 %时，再生料的结晶性能最好。

Modification of Recycled Polyethylene by Isomeric Crosslinking Method

In this work, crosslinked polyethylene (PE) was first prepared by a silane-crosslinking method, and then was melt-blended with the recycled PE obtained from the water-separated waste PE films. There was a change in aggregation structure observed from the fracture surfaces of blending samples by scanning electronic microscopy, Which indicates the formation of decentralized isomeric structure due to the incorporation of crosslinked PE into the recycled one. The effects of crosslinked PE content on mechanical and rheological properties were evaluated, and differential scanning calorimetry and X-ray diffraction were conducted to investigate the crystallinity and crosslinking degree of the blending sample containing 15 wt% of crosslinked PE. The results indicated that the tensile strength and impact toughness of the recycled PE were improved significantly due to the decentralized isomeric structure, whereas the elongation at break and melt flow rate showed a decline to some extent. The blend sample containing 15 wt% of the crosslinked PE was found to achieve an optimum performance and also exhibit the best crystallinity at a crosslinking degree of 33.5 %.