title: Supercritical CO₂ Foaming of Radiation Cross-Linked Isotactic Polypropylene in the Presence of TAIC.
abstract: Since the maximum foaming temperature window is only about 4 °C for supercritical CO₂ (scCO₂) foaming of pristine polypropylene, it is important to raise the melt strength of polypropylene in order to more easily achievescCO₂ foaming. In this work, radiation cross-linked isotactic polypropylene, assisted by the addition of a polyfunctional monomer (triallylisocyanurate, TAIC), was employed in thescCO₂ foaming process in order to understand the benefits of radiation cross-linking. Due to significantly enhanced melt strength and the decreased degree of crystallinity caused by cross-linking, thescCO₂ foaming behavior of polypropylene was dramatically changed. The cell size distribution, cell diameter, cell density, volume expansion ratio, and foaming rate of radiation-cross-linked polypropylene under different foaming conditions were analyzed and compared. It was found that radiation cross-linking favors the foamability and formation of well-defined cell structures. The optimal absorbed dose with the addition of 2 wt % TAIC was 30 kGy. Additionally, the foaming temperature window was expanded to about 8 °C, making the handling ofscCO₂ foaming of isotactic polypropylene much easier.
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jialuo Road 2019, Jiading, Shanghai 201800, China. yangchenguang@sinap.ac.cn.|University of China Academy of Sciences, Beijing 100049, China. yangchenguang@sinap.ac.cn.|School of Physical Science and Technology, ShanghaiTech University, Haike Road 100, Pudong, Shanghai 201210, China. yangchenguang@sinap.ac.cn.
authors.forename: Chen-Guang
authors.initials: CG
authors.lastname: Yang
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jialuo Road 2019, Jiading, Shanghai 201800, China. yangchg@shanghaitech.edu.cn.
authors.forename: Mou-Hua
authors.initials: MH
authors.lastname: Wang
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jialuo Road 2019, Jiading, Shanghai 201800, China. wangmouhua@sinap.ac.cn.
authors.forename: Ming-Xing
authors.initials: MX
authors.lastname: Zhang
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jialuo Road 2019, Jiading, Shanghai 201800, China. zhangmingxing@sinap.ac.cn.
authors.forename: Xiao-Hu
authors.initials: XH
authors.lastname: Li
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jialuo Road 2019, Jiading, Shanghai 201800, China. lixiaohushdx@163.com.
authors.forename: Hong-Long
authors.initials: HL
authors.lastname: Wang
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jialuo Road 2019, Jiading, Shanghai 201800, China. wanghonglong@sinap.ac.cn.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Xing
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jialuo Road 2019, Jiading, Shanghai 201800, China. xingzhe@sinap.ac.cn.
authors.forename: Lin-Feng
authors.initials: LF
authors.lastname: Ye
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jialuo Road 2019, Jiading, Shanghai 201800, China. wuguozhong@sinap.ac.cn.|School of Physical Science and Technology, ShanghaiTech University, Haike Road 100, Pudong, Shanghai 201210, China. wuguozhong@sinap.ac.cn.
authors.forename: Guo-Zhong
authors.initials: GZ
authors.lastname: Wu
mesh_terms: D000498:Allyl Compounds / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry* / Q000528:radiation effects; D003037:Cobalt Radioisotopes; D003432:Cross-Linking Reagents / Q000528:radiation effects*; D005720:Gamma Rays; D011108:Polymers / Q000737:chemistry*; D011126:Polypropylenes / Q000737:chemistry* / Q000528:radiation effects; D013696:Temperature
chemical_list: D000498:Allyl Compounds; D003037:Cobalt Radioisotopes; D003432:Cross-Linking Reagents; D011108:Polymers; D011126:Polypropylenes; D002245:Carbon Dioxide
keywords: TAIC; foaming; polypropylene; radiation cross-linking; supercritical carbon dioxide