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.

聚合物涂料在我们的环境中非常常见，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、表面化学和降解对工业非常重要（例如生产控制、耐久性和性能），以及其他相关领域，如艺术和保护科学（例如修复、鉴定赝品）和刑事调查（例如，在发生意外（工具漆、家用漆）、故意破坏（喷漆）或车祸（汽车漆）的情况下，比较可疑漆和参考漆的成分）。尽管这些领域面临着不同的问题，但它们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期间可能会受到风化和降解的影响。通过暴露于外部环境，聚合物涂层老化，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。油漆的风化和降解仍然是一项难以理解的任务，因为基质是一种动态介质。降解是许多因素的结合，包括成分的迁移或蒸发，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）、UV辐射或生物/化学污染物进一步催化。此外，最常见的油漆材料（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，并含有紫外线保护（受阻胺光稳定剂，HALS）、热稳定剂、机械改性剂或抗菌添加剂，这些都有助于其化学特征，并进一步增加了全面评估其降解的复杂性。文献调查表明，有一个重要的知识缺乏聚合物涂层的降解，这一直是接近的案例研究或具体的应用，但仍然不完全理解在更一般的水平。在我的探索研究计划中，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）通过使用自然和加速风化的影响因素的协同方法评估测年潜力，3）创建按涂料成分、分析方法、和降解条件。这项研究将与工业界合作，为聚合物的降解建立新的分析标准。此外，通过数据库收集和分享结果将对科学界产生直接和持久的影响。