在弹性聚氨酸urea中的紫外线诱导降解的光谱探测
Amritesh Kumar1, David Pullman2, George Youssef1
1Experimental Mechanics Laboratory, Mechanical Engineering Department, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA.
概括
紫外线 (UV) 辐射在环境条件下损坏聚氨酸涂层,增加键的破坏. 富含的环境显著地保护聚氨酸urea免受紫外线诱导的降解,保持其性能.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物化学 聚合物化学
- 频谱学是一种光谱学.
背景情况:
- 芳香聚尿素为防护涂层提供了出色的抗性特性.
- 聚尿素应用需要了解其在恶劣条件下的耐用性,包括紫外线 (UV) 辐射暴露.
- 光降解和光氧化是聚合物在现实世界部署中的关键问题.
研究的目的:
- 为了研究长时间紫外线辐射对芳香聚尿素的影响.
- 为了比较聚尿素在环境下与富含气氛中的降解途径.
- 阐明气环境对紫外线损伤的保护机制.
主要方法:
- 里埃变换红外光谱 (FTIR) 分析化学结构和键.
- 太赫兹时域光谱 (THz-TDS) 探测复杂折射率的变化.
- 激发发射矩阵光谱 (EEMS) 用于检测光变异.
主要成果:
- 环境空气中的紫外线暴露增加了键障碍,并改变了聚尿素中的键长度.
- 在气氛下暴露于紫外线的多尿素样本显示结构变化最小.
- THz-TDS证实了FTIR发现,将光谱变化与紫外线暴露时间相关联.
- 在环境条件下,EEMS在暴露于紫外线9-12周的样本中发现了光,表明集群触发的排放.
结论:
- 屏蔽有效地保护聚尿素免受紫外线诱导的光降解和光氧化.
- 光谱技术总的来说证明了紫外线辐射对聚尿素结构完整性的有害影响.
- 了解这些降解机制对于提高聚尿素在苛刻环境中的寿命至关重要.
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