处女和回收聚烯-高密度聚乙烯混合物的热力学特性
Hannah Jones1, Jake McClements2, Dipa Ray1
1School of Engineering, Institute for Materials and Processes, The University of Edinburgh, Sanderson Building, King's Buildings, Edinburgh EH9 3FB, UK.
Polymers
|November 14, 2023
概括
回收聚烯/高密度聚乙烯混合物由于降解而显示减少的热和机械性能,影响其在循环经济中的使用. 需要进一步的研究来理解和减轻这些变化.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物科学 聚合物科学
- 回收技术的回收技术
背景情况:
- 回收聚合物混合物的热力学行为的变化研究不足.
- 了解回收材料的性能对于循环经济倡议至关重要.
- 回收材料的不均性对一致的应用提出了挑战.
研究的目的:
- 系统地研究原始和回收聚烯/高密度聚乙烯混合物的热和机械性能.
- 为这些混合物中热力学行为的变化提供证据.
- 为了解回收聚合物的性能做出贡献,以便更广泛地重新进入市场.
主要方法:
- 差分扫描热量计 (DSC) 用于评估热性能和可混合性.
- 动态机械分析 (DMA) 来评估粘弹性行为和放松过渡.
- 拉伸测试用于确定机械性能,如扬模量,屈服强度和破裂时的延伸.
主要成果:
- 再循环和原始混合物都被发现是通过DSC.不混合的.
- 回收混合物呈现较低的整体结晶度和化温度,但结晶温度相似.
- 在回收混合物中,DMA显示了较低的α和β放松温度,表明结构恶化.
- 拉伸测试显示,与原始混合物相比,回收混合物中的模和收益强度较低,但在断裂时延伸度更高.
结论:
- 回收过程中的结构降解和污染物导致回收混合物中的聚合物链较短和不完美的晶体.
- 观察到的热和机械性能恶化限制了这些回收混合物的直接应用.
- 在回收混合物中,破裂时的较高延长可能归因于低分子量链片段,这表明了特定应用的潜力.
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