中国塑料 ›› 2024, Vol. 38 ›› Issue (7): 55-61.DOI: 10.19491/j.issn.1001-9278.2024.07.010

• 加工与应用 • 上一篇    下一篇

茂金属聚丙烯釜压发泡性能的研究

沈强锋1(), 吕明福2, 徐耀辉2()   

  1. 1.中石化宁波新材料研究院有限公司,浙江 宁波,315299
    2.中石化(北京)化工研究院有限公司,北京 100013
  • 收稿日期:2024-04-19 出版日期:2024-07-26 发布日期:2024-07-24
  • 通讯作者: 徐耀辉(1980—),男,研究员,主要从事聚合物轻量化材料开发研究,xuyh.bjhy@sinopec.com
    E-mail:shqf.zhlh@sinopec.com;xuyh.bjhy@sinopec.com
  • 作者简介:沈强锋(1966—),男,高级工程师,从事聚烯烃新产品的开发等方面的研究,shqf.zhlh@sinopec.com

Study on autoclave foaming properties of metallocene polypropylene

SHEN Qiangfeng1(), LYU Mingfu2, XU Yaohui2()   

  1. 1.Sinopec Ningbo New Materials Research Institute Company Limited,Ningbo 315299,China
    2.SINOPEC(Beijing) Research Institute of Chemical Industry Co,Ltd,Beijing 100013,China
  • Received:2024-04-19 Online:2024-07-26 Published:2024-07-24
  • Contact: XU Yaohui E-mail:shqf.zhlh@sinopec.com;xuyh.bjhy@sinopec.com

摘要:

采用差示扫描量热和偏光显微镜考察了茂金属催化剂制备PP(mPP)和齐格勒⁃纳塔催化剂制备PP(ZNPP)的熔融结晶行为;采用频率扫描和熔体拉伸的方法,考察了它们的流变学特征。进行釜压发泡实验并对发泡珠粒的熔融结晶、发泡倍率和泡孔结构进行测试表征。结果表明,由于分子量大小及分布的影响,ZNPP具有更高的表观黏度,以及更显著的剪切变稀现象;因为ZNPP分子链缠结更强烈,故在较高温度下熔体强度高于mPP,但在较低温度下二者熔体强度相近。较ZNPP,mPP可以制得倍率相近的釜压发泡PP(EPP)珠粒,但泡孔形态质量有待于进一步提高。

关键词: 茂金属聚丙烯, 剪切变稀, 熔体强度, 釜压发泡, 泡孔结构

Abstract:

The melting and crystallization behavior of two types of polypropylene, named as mPP and ZNPP, were studied by using differential scanning calorimeter (DSC) and polarized microscope (POM), and their rheological characteristics were analyzed through frequency scanning and melt stretching. Autoclave foaming experiments were conducted to investigate the melting crystallization behavior, foaming ratio, and cell structure of the expanded polypropylene (EPP) beads. The results indicated that ZNPP had a higher complex viscosity and more obvious shear thinning, leading to higher molecular weight size and distribution. ZNPP exhibits higher melting strength than mPP at higher temperatures due to more intense molecular chain entanglement. However, its melt strength is similar to that of mPP at lower temperatures. The quality of the cell structure needs to be improved, when mPP is used to produce EPP beads with similar ratios to ZNPP.

Key words: metallocene polypropylene, shear thinning, melt strength, autoclave foaming, cell structure

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