Journal of Radiation Research and Radiation Processing ›› 2019, Vol. 37 ›› Issue (5): 2-050201-9.doi: 10.11889/j.1000-3436.2019.rrj.37.050201

• RADIATION CHEMISTRY • Previous Articles     Next Articles

Supercritical carbon dioxide foaming behavior and properties of radiation cross-linked polypropylene random copolymer

WANG Jixiang1,3(),XIE Fanghua1(),ZENG Hongyan1,YANG Junjie2,HUANG Chenghui2,YANG Chenguang3,LI Hui3,WU Guozhong2,3()   

  1. 1. School of Chemical Engineering, Xiangtan University, Xiangtan 411105, China
    2. Zhejiang Sinco-polymer Material R&D Centre, Jiashan 314100, China
    3. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
  • Received:2019-02-26 Revised:2019-03-21 Accepted:2019-03-21 Online:2019-10-20 Published:2019-10-15
  • Contact: Fanghua XIE,Guozhong WU;;
  • About author:WANG Jixiang(male) was born in November 1993, and obtained his bachelor’s degree from Henan Polytechnic University in 2016. Now he is a master candidate at the School of Chemical Engineering, Xiangtan University.
  • Supported by:
    the Science Challenge Project(TZ2018004)


Polypropylene random copolymer (PPR) was mixed with triallyl isocyanurate (TAIC) and pressed into a sheet. PPR sheets were irradiated by γ-rays and then foamed by supercritical carbon dioxide. The effects of TAIC and absorbed dose on the structure and foaming ability of PPR were evaluated by the gel fraction test and by determining the crystallization behavior and foam cellular structure. It was found that PPR was cross-linked by TAIC. After irradiation, the degree of crosslinking in PPR/TAIC(2%) increased, and the degree of oxidative degradation increased with absorbed dose. α and γ crystals were observed in PPR, and more γ crystals were found after crosslinking. The γ crystals induced more nucleation sites and formed better foams. The optimal absorbed dose obtained in this study was 25 kGy. The cell diameter decreased to 41 μm and the cell density increased to 1.5 × 1010 cm-3. The tensile strain of the sample reached 230%, and the suitable foaming temperature window reached 10 ℃ at the release pressure of 20 MPa.

Key words: Polypropylene random copolymer (PPR), Radiation crosslinking, γ-crystal, Crystallinity, Supercritical carbon dioxide foaming

CLC Number: 

  • TL13