高温大小排除色谱与三重检测,以评估低密度聚乙烯的分子结构:洞察分支和可加工性相关性
Yogesha Subbaiah1, Senthilkumar Shanmugam1, Qua Eng Hau1
1TASNEE Technology and Innovation Centre, R & D Laboratory, National Industrialization Company, Al Jubail, Kingdom of Saudi Arabia.
Journal of separation science
|January 29, 2024
概括
高级尺寸排除色谱 (SEC) 揭示了低密度聚乙烯 (LDPE) 中复杂的分子结构. 这项研究增强了对LDPE分子重量和分支的理解,这对于聚合物加工行为至关重要.
科学领域:
- 聚合物化学 聚合物化学
- 材料科学 材料科学 材料科学
背景情况:
- 低密度聚乙烯 (LDPE) 是一种具有复杂分子架构的广泛使用的聚合物.
- 传统的尺寸排除色谱 (SEC) 方法可能无法完全捕捉LDPE的结构复杂性.
研究的目的:
- 研究商业LDPE中的分子量 (MW),MW分布,短链分支 (SCB) 和长链分支 (LCB).
- 为了将聚合物分支特征与质性质相关联,特别是胀比率.
- 为了比较使用先进的SEC探测器与传统校准技术的MW确定.
主要方法:
- 高温尺寸排除色谱 (SEC) 与红外-5 (IR-5),粘度计 (VISCO) 和多角度激光光散射 (MALS) 探测器相结合.
- 对3个具有不同融化流速 (4.0,1.9和0.75g/10分钟) 的LDPE样本进行分析.
- 确定散装SCB和LCB参数,以及风湿学性质 (死亡膨胀比).
主要成果:
- 与传统校准相比,先进的SEC技术产生了更高的MW值 (1.43-1.7倍),这归因于LDPE的结构复杂性.
- 每1000个碳素中的散装SCB在16.50到17.80之间 (IR-5).
- 每1000个碳的LCB频率在0.46到0.54 (VISCO) 和0.65到0.94 (MALS) 之间.
结论:
- 先进的SEC探测器对于准确地描述LDPE的复杂分子结构至关重要.
- 长链分支显著影响LDPE的质行为和加工特性.
- 这一全面的分析为优化LDPE生产和应用提供了关键数据.
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