Degradation of Cellulose-based polymers in complex environments

纤维素基聚合物如醋酸纤维素作为生物基材料越来越受到关注。然而，它们的环境可降解性是一个复杂的问题。每年大约有4.5万亿个醋酸纤维素香烟过滤嘴被丢弃，这些过滤嘴通常作为垃圾长期存在相比之下，许多博物馆藏品中的纤维素基聚合物已经被观察到迅速腐烂，导致宝贵的文化遗产的损失具体的降解机制，如水解去乙酰化和光解链断裂是已知的。然而，需要了解这些降解机制在复杂环境中的相互作用方式，以便更好地了解这些材料在自然环境和博物馆中是如何降解的伦敦大学学院可持续遗产研究所和伦敦大学学院可持续资源研究所之间的合作项目旨在了解这些相互作用。除了物理性质的变化外，还将探讨光氧化和水解过程之间的关系。该学生将进行加速老化实验，并使用核磁共振（NMR）和傅里叶变换红外（FTIR）光谱、凝胶渗透色谱（GPC）和拉伸测试等分析技术来了解材料性能的变化。预计该项目将对持久性塑料垃圾问题和遗产保护产生重大影响。

Cellulose-based polymers such as cellulose acetate are of increasing interest as bio-based materials. However, their environmental degradability is a complex question. Approximately 4.5 trillion cellulose acetate cigarette filters are discarded annually and these are often persistent as litter.1 In contrast, cellulose-based polymers in many museum collections have been observed to decay rapidly, leading to loss of valuable cultural heritage.2 Specific degradation mechanisms such as hydrolytic deacetylation and photolytic chain scission are known. However, an understanding of the way these degradation mechanisms interact in complex environments is needed to better understand how these materials degrade, both in the natural environment and in museums.3 This collaborative project between the UCL Institute for Sustainable Heritage and the UCL Institute for Sustainable Resources aims to understand these interactions. Relationships between photo-oxidative and hydrolytic processes will be explored, in addition to accompanying changes in physical properties. The student will conduct accelerated aging experiments and use analytical techniques such as Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR) spectroscopies, Gel Permeation Chromatography (GPC) and tensile testing to understand changes in material properties. This project is expected to have a significant impact on both the issue of persistent plastic litter and on heritage conservation.