中国塑料 ›› 2024, Vol. 38 ›› Issue (2): 82-86.DOI: 10.19491/j.issn.1001-9278.2024.02.013

• 助剂 • 上一篇    下一篇

十二烷基硫酸钠表面改性水滑石对PVC热稳定性能的影响

李先铭1, 张宁2,3(), 李改花2,3, 刘爽2, 刘征原2   

  1. 1.唐山师范学院物理科学与技术学院,河北 唐山 063000
    2.唐山师范学院化学系,河北 唐山 063000
    3.河北省可降解聚合物重点实验室,河北 唐山 063000
  • 收稿日期:2023-06-19 出版日期:2024-02-26 发布日期:2024-02-03
  • 通讯作者: 张宁(1979—),女,教授,主要研究方向为高分子材料加工助剂,zhni0827@163.com
    E-mail:zhni0827@163.com
  • 基金资助:
    唐山师范学院科研项目(2023C14)

Effect of sodium dodecyl sulfate surface⁃modified hydrotalcite on thermal stability of PVC

LI Xianming1, ZHANG Ning2,3(), LI Gaihua2,3, LIU Shuang2, LIU Zhengyuan2   

  1. 1.School of Physical Science and Technology,Tangshan Normal University,Tangshan 063000,China
    2.Department of Chemistry,Tangshan Normal University,Tangshan 063000,China
    3.Hebei Key Laboratory of Degradable Polymers,Tangshan 063000,China
  • Received:2023-06-19 Online:2024-02-26 Published:2024-02-03
  • Contact: ZHANG Ning E-mail:zhni0827@163.com

摘要:

采用十二烷基硫酸钠(SDS)对镁铝镧碳酸根型水滑石(LDHs)表面进行湿法改性,讨论了不同改性条件对聚氯乙烯(PVC)静态热稳定性能的影响,通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)和红外光谱仪(FTIR)进行表征。采用刚果红试纸法、烘箱变色法、转矩流变法、热重分析法等测定了SDS改性前后PVC/LDHs样品的热稳定性能。结果表明,恒定pH=7,SDS为LDHs质量的10 %,水浴80 ℃下搅拌3 h,改性效果最佳;SDS并未破坏LDHs的晶体结构,仅吸附在表面,增强了与PVC的相容性;改性后的PVC/LDHs样品静态及动态热稳定时间达65、28.5 min,改善了后期着色,更易塑化成型;最大质量损失速率对应温度为346 ℃,较未添加前增加55 ℃,能较好地抑制PVC的热降解。

关键词: 聚氯乙烯, 类水滑石, 表面改性

Abstract:

Sodium dodecyl sulfate (SDS) was used to modify magnesium⁃aluminum⁃lanthanum carbonate hydrotalcite (LDHs), and the effect of different modification conditions on the static thermal stability of poly(vinyl⁃chloride) (PVC) was investigated.The molecular structures of modified PVC samples were characterized by using X⁃ray diffractometry, scanning electron microscopy, and infrared spectroscopy. The thermal stabilities of the PVC samples with modified and unmodified LDHs were evaluated by means of Congo red test paper method, thermal aging oven method, torque rheometer, and thermogravimetric analysis. The results indicated the modification effect was best at a constant pH value of 7 and a mass ratio of SDS to LDHs of 1/10 in a water bath at 80 ℃ for 3 h. SDS did not change the crystal structure of hydrotalcite but was only adsorbed on the surface of LDHs, which enhanced its compatibility with PVC. The static and dynamic thermal stability times of the PVC/LDHs samples using the LDHs modified SDS for 65 and 28.5 min, respectively. Meanwhile, the later coloring of PVC samples was improved to make plasticize and form more easily. The temperature corresponding to the maximum weight loss rate of the modified PVC sample was 346 ℃, which increased by 55 ℃ compared to pure PVC. This could effectively inhibit the thermal degradation of PVC.

Key words: poly(vinyl chloride), hydrotalcite?like, surface modification

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