中国塑料 ›› 2008, Vol. 22 ›› Issue (12): 16-21 .DOI: 10.19491/j.issn.1001-9278.2008.12.004

• 材料与性能 • 上一篇    下一篇

动态保压注塑成型下少量PE-HMW对PE-HD结晶形态的影响

王荣飞;高 磊;申开智   

  1. 四川大学高分子科学与工程学院,高分子材料工程国家重点实验室,四川 成都 610065
  • 收稿日期:2008-09-11 修回日期:1900-01-01 出版日期:2008-12-26 发布日期:2008-12-26

Effect of A Small Amount of High-molecular-weight Polyethylene on Crystal Morphology of High-density Polyethylene under Dynamic Packing Injection Molding

WANG Rong-fei;GAO Lei;SHEN Kai-zhi   

  1. State Key Laboratory of Polymer Material Engineering, College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China
  • Received:2008-09-11 Revised:1900-01-01 Online:2008-12-26 Published:2008-12-26
  • Contact: WANG Rong-fei

摘要: 采用自制动态保压注塑成型设备,研究了少量高相对分子质量聚乙烯(PE-HMW)对高密度聚乙烯(PE-HD)剪切诱导结晶的影响。在PE-HD中添加PE-HMW后再通过动态保压注射成型,可获双向自增强的制品,其中纵向与横向的拉伸强度由普通成型制品的28 MPa分别提高到76 MPa和32 MPa,纵向冲击强度从普通成型制品的2.0×105 kJ/m2提高到8.7×105 kJ/m2。用扫描电镜观察该制品发现,在PE-HD / PE-HMW的剪切层中有大量互锁的串晶生成,从而能够实现单向剪切应力场下制品的双向自增强;用差示扫描量热仪进一步表征得知,其串晶中央的脊纤维晶较长,而折叠链片晶也得到了增厚,故具有较高熔点。

关键词: 高密度聚乙烯, 高分子量聚乙烯, 结晶形态, 串晶, 动态保压

Abstract:

This paper reports the effect of high-molecular-weight polyethylene (PE-HMW) on the crystal morphology of high-density polyethylene (PE-HD) specimen. The PE-HD specimen containing a small amount of PE-HMW prepared via dynamic packing injection molding was found to be obviously reinforced. The tensile strengths were increased from 28 MPa to 76 MPa in machine direction and to 32 MPa in transverse direction, the impact strength of them increased from 2.0×105 kJ/m2 to 8.7×105 kJ/m2 in machine direction. Electron microscopy micrograph indicated that there were abundant interlocking shish-kebab crystals present in shear layers. DSC confirmed the formation of central long shish structure and thickened kebabs which exhibit a higher thermal stability.

Key words: high-density polyethylene, high-molecular-weight polyethylene, crystal morphology, shish-kebab, dynamic packing

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