Journal of Radiation Research and Radiation Proces ›› 2018, Vol. 36 ›› Issue (1): 10301-010301.doi: 10.11889/j.1000-3436.2018.rrj.36.010301

• RADIATION CHEMISTRY • Previous Articles     Next Articles

Gamma-ray irradiation effects on scCO2 foaming behavior of polypropylene

YANG Chenguang1,2, ZHAO Quan1, WANG Mouhua1, XING Zhe1, WU Guozhong1   

  1. 1. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jiading Campus, Shanghai 201800, China;
    2. University of China Academy of Sciences, Beijing 100049, China
  • Received:2017-08-25 Revised:2017-11-27 Online:2018-02-20 Published:2018-02-08
  • Supported by:

    Supported by National Natural Science Foundation of China (11079048)

Abstract:

The effects of γ-ray irradiation on the supercritical carbon dioxide (scCO2) foaming behavior of polypropylene (PP) were systematically studied. Sheets of PP were prepared through two different methods: irradiation after hot pressing (Sequence I, SI), and hot pressing after irradiation (Sequence II, SII). Carbon dioxide was used as the physical foaming agent. It was found that the crystallinities (51% to 40%) and melting points decreased with the increasing absorbed doses. At low frequency, the complex viscosity of PP decreased after irradiation, and the decrease was more pronounced for PP(SII) than PP(SI). The PP(SI) foam possessed an uniform cell size and a higher foaming rate, and its tensile strength increased from 3.9 MPa to 7.1 MPa compared with those of pure PP and PP(SII). In addition, at the optimum absorbed dose of 30 kGy, the suitable foaming temperature was around 145~153 ℃, and a wider foaming temperature (6~8 ℃) was obtained compared with the original 4 ℃. Therefore, irradiation after hot pressing (i.e., SI) was considered more suitable for the foaming of irradiated PP, resulting in a higher tensile strength and a wider foaming temperature window.

Key words: γ-ray irradiation, Polypropylene, Supercritical CO2 foaming, Tensile strength, Rheological property

CLC Number: 

  • TL13