中国塑料 ›› 2025, Vol. 39 ›› Issue (9): 1-6.DOI: 10.19491/j.issn.1001-9278.2025.09.001

• 材料与性能 •    

支化结构聚丙烯的超临界CO2模压发泡及其力学性能

王硕1, 袁文博2, 陈弋翀1, 臧云涛2, 冷栋梁2, 李海艳2, 赵玲1, 胡冬冬1()   

  1. 1.华东理工大学化工学院,化学工程联合国家重点实验室,上海 200237
    2.山东京博聚烯烃新材料有限公司,山东 滨州 256500
  • 收稿日期:2024-09-13 出版日期:2025-09-26 发布日期:2025-09-22
  • 通讯作者: 胡冬冬(1989—),男,副教授,从事超临界流体辅助聚合物加工,hudd@ecust.edu.cn
    E-mail:hudd@ecust.edu.cn
  • 基金资助:
    国家自然科学基金面上项目(22378113)

Mechanical performance of branched polypropylene foams fabricated via supercritical CO₂ molding

WANG Shuo1, YUAN Wenbo2, CHENG Yichong1, ZANG Yuntao2, LENG Dongliang2, LI Haiyan2, ZHAO Ling1, HU Dongdong1()   

  1. 1.School of Chemical Engineering,State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China
    2.Shandong Chambroad Polyolefin Performance Materials Co,Ltd,Binzhou 256500,China
  • Received:2024-09-13 Online:2025-09-26 Published:2025-09-22
  • Contact: HU Dongdong E-mail:hudd@ecust.edu.cn

摘要:

以过氧化二异丙苯(DCP)为引发剂、一硫化四甲基秋兰姆(TMTM)和季戊四醇三丙烯酸酯(PETA)为双单体,制备了具有不同支化程度的聚丙烯(PP),并采用超临界CO2模压发泡制备PP发泡材料。考察了不同支化程度对改性PP的分子量及其分布、熔融结晶、流变行为和发泡行为的影响。结果表明,随着支化程度的增加,结晶温度逐渐升高;相对于线形PP,支化结构PP的结晶度较低;支化程度的提高导致熔体黏弹性增强,松弛时间延长,且剪切稀化和应变硬化现象逐渐显著,发泡温度区间拓宽至12 ℃;改性样品的在15 MPa、152 ℃发泡条件下的最高发泡倍率30倍且呈现更为均匀的泡孔结构。经改性的PP发泡产品(25倍)最优压缩模量可达(18.94±0.55) MPa,最优拉伸模量为(3.51±0.06)MPa,拉伸和压缩性能优于相同倍率下的E02ES发泡产品。

关键词: 均聚聚丙烯, 支化, 超临界二氧化碳, 模压发泡, 力学性能

Abstract:

Polypropylene (PP) with varying degrees of branching was prepared using dicumyl peroxide (DCP) as an initiator and tetramethyl thiuram monosulfide (TMTM) combined with pentaerythritol triacrylate (PETA) as dual monomers. The modified PP was foamed via supercritical CO₂ molding, and the influence of branching degree on molecular weight, molecular weight distribution, melt crystallization, rheological behavior, and foaming performance was systematically investigated. Results indicated that the crystallization temperature of PP gradually increased with higher branching degrees, while crystallinity degree decreased compared to linear PP. Enhanced branching also improved melt viscoelasticity, prolonged relaxation time, and intensified shear thinning and strain hardening effects. Furthermore, the foaming temperature window expanded by 12 ℃. Under optimal conditions (15 MPa CO₂, 152 ℃), the modified PP achieved a maximum expansion ratio of 30⁃fold, exhibiting a more uniform cell structure. The foam with a 25⁃fold expansion ratio demonstrated superior mechanical properties, with compression and tensile moduli reaching (18.94±0.55)MPa and (3.51±0.06)MPa, respectively, outperforming the E02ES™ foam at the same expansion ratio.

Key words: homopolymer polypropylene, branching, supercritical carbon dioxide, molding foaming, mechanical property

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