聚乙烯糖醇对聚L-乳酸和聚D-乳酸混合物的非同热结晶的影响
Panthima Phuangthong1, Wenwei Li1,2, Jun Shen1,2
1Manufacturing and Materials Research Unit, Department of Manufacturing Engineering, Faculty of Engineering, Mahasarakham University, Mahasarakham 44150, Thailand.
Polymers
|August 10, 2024
概括
将聚乙烯甘醇 (PEG) 添加到多L-乳酸/多D-乳酸混合物中,可显著增强立体复合PLA (sc-PLA) 的形成. 低分子量PEG有效地促进sc-PLA,改善材料性能.
科学领域:
- 聚合物科学 聚合物科学
- 材料科学 材料科学 材料科学
- 结晶工程 结晶工程
背景情况:
- 聚乙烯-乳酸 (PLLA) 和聚乙烯-乳酸 (PDLA) 混合物形成的聚乙烯立体复合体 (sc-PLA) 提高了机械强度和耐热性.
- 了解同晶体 (HCs) 和立体复合晶体 (SCs) 的竞争性结晶对于优化sc-PLA特性至关重要.
- 聚乙烯甘醇 (PEG) 被探索为一种添加剂,以影响PLLA/PDLA混合物的结晶行为.
研究的目的:
- 研究聚乙烯糖醇 (PEG) 分子重量和度对50/50的PLLA/PDLA混合物中同晶体 (HCs) 和立体复合晶体 (SCs) 的竞争性结晶的影响.
- 确定PEG如何影响结晶温度,化行为以及整体立体复合体形成的比例.
- 评估PEG作为塑化剂对PLLA/PDLA混合物的热性能的影响.
主要方法:
- 差分扫描热量计 (DSC) 用于分析不同度和分子重量 (400 g/mol和35,000 g/mol) 的PLLA/PDLA混合物的热性能和结晶行为.
- 在这项研究中,研究人员检查了5%,10%,15%和20%重量添加PEG的混合物.
- 在不同的冷却速率 (2,5,10,20°C/分钟) 下,研究了结晶动力学.
主要成果:
- 添加PEG增加了结晶温度,并显著促进了立体复合体 (SC) 的形成,同时抑制了同晶体 (HC) 的形成.
- 聚烯充当了增塑剂,降低了化和结晶温度.
- 添加5%的低分子量PEG (400g/mol) 导致完全的SC形成 (100%的SC分数),而高分子量PEG (35,000g/mol) 的效果较低,允许一些HC形成.
- 在所有测试的冷却速率中,PEG始终提高了SC的形成.
结论:
- 低分子量聚乙烯甘醇 (PEG) 在促进PLLA/PDLA混合物中的立体复合聚酸 (sc-PLA) 形成方面非常有效.
- PEG既是SCs的结晶促进剂,也是塑化剂,影响混合物的热特性.
- PEG的分子量是实现高立体复杂分量的关键因素,较低的分子量产生更好的结果.
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