The degradation and weathering of modern polymer coatings: assessment and monitoring of the chemical signature

现代聚合物涂料的降解和风化：化学特征的评估和监测

• 批准号: RGPIN-2019-04827
• 负责人: Muehlethaler, Cyril
• 金额: $ 2.04万
• 依托单位: Université du Québec à Trois-Rivières
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=748766
• 关键词: degradation; weathering; modern; polymer; coatings

Polymer coatings are extremely common in our environment and used for protection, decoration or even sanitation of surfaces and objects. Understanding their structure-property relationship, rheology, surface chemistry, and degradation is therefore important for industry (e.g. control of production, durability, and performance), and other related fields such as art and conservation science (e.g. restoration, identification of counterfeited paintings) and criminal investigations (e.g. comparing the composition of suspected and reference paints in case of burglaries (tool paint, domestic paint), vandalism (spray paint), or car accidents (automotive paint)). Each of these fields, although facing distinct problematics, have one common analytical challenge: the coatings under analysis will potentially be subject to weathering and degradation over their lifetime. Through being exposed to the exterior environment, polymer coatings age, degrade, and acquire an altered chemical signature. The challenge for the scientific community is to understand these variations in order to predict the long-term weathering of polymer coatings. The weathering and degradation of paints is nonetheless a difficult task to apprehend, as the matrix is a dynamic medium. The degradation is a combination of many factors, including the migration or evaporation of components, and some physico-chemical modifications of the structure (oxidation, cross-linking). All these effects can further be catalyzed by heat, water (moisture), UV radiation, or biological/chemical contaminants. Additionally, the most common paint materials (i.e. acrylic, alkyd, polyurethane, polyester) have different rheologic properties and surface chemistry, and contain UV protection (hindered amines light stabilizers, HALS), heat stabilizers, mechanical modifiers, or anti-microbial additives that all contribute to their chemical signature and further increase the complexity of comprehensively evaluate their degradation. A survey of the literature shows that there is an important lack of knowledge on the degradation of polymer coatings, which has always been approached by case studies or specific applications, but remains incompletely understood at a more general level. In my Discovery research program, I intend to answer the following objectives: 1) Thorough evaluation of the influencing factors that contribute to degradation and their physical and chemical outcomes, 2) Assessment of the dating potential by a synergistic approach of the influencing factors using natural and accelerated weathering, 3) Creation of a comprehensive database of chemical signatures organized by paint compositions, analytical methods, and degradation conditions. This research will establish new analytical standards for the degradation of polymers in collaboration with the industry. Additionally, collecting and sharing the results through a database will have a direct and lasting impact on the scientific community.

聚合物涂层在我们的环境中极为常见，用于保护、装饰甚至表面和物体的卫生。因此，了解它们的结构-性能关系、流变学、表面化学和降解对于工业（例如生产控制、耐久性和性能）以及艺术和保护科学等其他相关领域（例如修复、假冒绘画的识别）非常重要刑事调查（例如，在盗窃（工具油漆、家用油漆）、故意破坏（喷漆）或车祸（汽车油漆）的情况下比较可疑油漆和参考油漆的成分）。这些领域中的每一个虽然都面临着不同的问题，但都面临着一个共同的分析挑战：所分析的涂层在其使用寿命内可能会遭受风化和降解。通过暴露在外部环境中，聚合物涂层会老化、降解并获得改变的化学特征。科学界面临的挑战是了解这些变化，以预测聚合物涂层的长期风化情况。尽管如此，油漆的风化和降解仍然是一项艰巨的任务，因为基质是一种动态介质。降解是多种因素综合作用的结果，包括组分的迁移或蒸发，以及结构的一些物理化学修饰（氧化、交联）。所有这些效应都可以通过热、水（湿气）、紫外线辐射或生物/化学污染物进一步催化。此外，最常见的涂料材料（即丙烯酸、醇酸、聚氨酯、聚酯）具有不同的流变特性和表面化学性质，并含有紫外线防护（受阻胺光稳定剂，HALS）、热稳定剂、机械改性剂或抗菌添加剂，所有这些都有助于其化学特征，并进一步增加了综合评估其降解的复杂性。文献调查表明，人们对聚合物涂层降解的认识严重缺乏，人们一直通过案例研究或具体应用来解决这一问题，但在更一般的层面上仍然不完全理解。在我的发现研究计划中，我打算回答以下目标：1）彻底评估导致降解的影响因素及其物理和化学结果，2）利用自然影响因素的协同方法评估约会潜力和加速风化，3) 创建按涂料成分、分析方法和降解条件组织的化学特征综合数据库。这项研究将与业界合作建立聚合物降解的新分析标准。此外，通过数据库收集和共享结果将对科学界产生直接和持久的影响。