重复的热机械加工对瓶级PET在受控条件下的降解行为的影响
Mária Straková1, Slávka Hlaváčiková1, Jozef Feranc1
1Institute of Natural and Synthetic Polymers, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37 Bratislava, Slovakia.
Polymers
|February 13, 2026
概括
聚乙烯二甲 (PET) 的机械回收会在重复加工时导致降解. 这项研究量化了PET性能变化,揭示了回收PET在苛刻的应用中重复使用的极限.
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
- 化学工程是化学工程的重要组成部分.
背景情况:
- 聚乙烯二甲 (PET) 的机械回收对于循环包装至关重要.
- 在回收过程中重复的热力学处理会导致聚合物降解,限制材料的再利用.
研究的目的:
- 在受控的重复挤压条件下,系统地研究瓶级PET的降解行为.
- 量化多个加工周期对PET化学,物理和机械性能的影响.
主要方法:
- 模拟机械回收使用一个共旋双螺杆挤出机,最多四个周期 (8分钟累计停留时间).
- 测量了内在粘度,分子量,化流速,玻璃过渡和化温度,结晶度和机械性能 (破裂时的延长).
- 进行光学分析以评估材料颜色变化 (L*亮度).
主要成果:
- 渐进的加工导致了链裂变,降低了内在粘度 (0.80至0.65dL·g-1) 和分子重量.
- 融化流量增加,表明融化强度降低;结晶度增加 (23.0%至29.5%).
- 柔性降低 (84%至60%的断裂延长),材料变暗,与内在粘度损失相关.
结论:
- 控制的实验室挤出量化了回收PET的内在热力学降解效应.
- 瓶级PET仅在有限的加工周期后才能保持要求高的应用的性能.
- 进一步加工将PET的可用性限制在纤维或非食品包装等要求较低的应用中.
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