Investigation into the release of microplastics and metallic ions into the environment during the long-term degradation of pre-painted metals

导言：作为其绿色协议的一部分，欧盟委员会正在调查产品在其使用寿命期间产生的微塑料和化学物质（有意或无意）。欧洲卷材涂料协会（ECCA）正在赞助一项调查，研究有机涂层形成的微塑料，以及预涂金属长期降解过程中化学物质的释放（“径流”）。考虑到预涂金属的耐久性（大约40年），确定在此期间涂层产品形成的微塑料和其他颗粒的程度（如果有的话）是很重要的。虽然目前没有与这些问题相关的法规，但可以想象，未来的立法可能会要求采取减少措施，以防止微塑料和金属离子的释放。研究的目的和范围：本工作的主要目的是通过以下途径确定预涂金属制品降解过程中微塑料和其他颗粒形成的主要机制：使用先进的分析技术，如紫外线，ATR， FTIR， SEM和粒度测定，以确定主要涂层降解的机制和速率，如机械，紫外线，并了解通过侵蚀释放的有机和无机颗粒的性质。通过深度剖面和表面分析技术了解代表性气候条件如何影响侵蚀速率和涂层特性的变化。3. 对涂层样品释放的流失物质进行详细调查。加速测试结果与自然风化材料的相关性，特别关注环境释放的类型和数量。在整个欧盟范围内，室外预涂金属暴露每年释放总量的量化。实验设计将包括以下系统的适当数量和组合：(a)聚酯，聚氨酯，PVDF和塑料溶胶涂层金属。(b)镀锌钢和铝基材。(c)可迅速降解并释放化学成分（如聚酰胺珠）的“模型”有机涂层。拟议的工作范围也可酌情扩大，以包括下列主题：(i)确定释放的物种在环境中的命运，例如生物聚集的地点。一旦释放到环境中，进一步的降解机制。（iii）释放的物种对环境的影响，例如生物毒性的证据。预测结果：该项目将为有机物质和金属离子可能释放到环境中提供了解。这可能使ECCA成员能够制定改进的有机涂料，减少对环境的影响，这将保持产品在欧洲市场的竞争地位。

Introduction:The European Commission, as part of their Green Deal, are investigating the generation (intentional or not) of microplastics and chemical species from products during their service life. The European Coil Coating Association (ECCA) is sponsoring an investigation into the formation of microplastics from the organic coating and the release ("run-off") of chemical species during the long-term degradation of prepainted metals. Given the durability of prepainted metals (>40 years), it is important to establish the extent (if any) of microplastic and other particulate formation from the coated product over this period. Whilst there is no current regulation related to these issues, it is conceivable that future legislation may require abatement measures to prevent release of both microplastics and metallic ions.Objective and scope of the study:The primary objective of the work is to identify the main mechanisms for microplastic and other particulate formation during the degradation of the prepainted metal product through:1. The use of advanced analytical techniques such as UV, ATR FTIR, SEM and particle sizing to determine the mechanism and rates of major coating degradation e.g. mechanical, UV and to understand the nature of the organic and inorganic particulates released through erosion.2. Understanding how representative climatic conditions affect the rates of erosion and changes in coating characteristics using through depth profiling and surface analysis techniques. 3. Detailed investigation of the run-off material released from the coated samples.4. Correlation of accelerated testing results with naturally weathered material with particular focus on the types and quantity of environmental release.5. Quantification of the total yearly releases from outdoor prepainted metal exposure, over the whole of the EU.The experimental design will include an appropriate number and combination of the following systems:(a) Polyester, polyurethane, PVDF and plastisol coated metal.(b) Zinc-coated steel and aluminium substrates.(c) "Model" organic coatings which will rapidly degrade and release chemical components e.g. polyamide beads.The proposed scope of work could also be extended, where appropriate, to include such topics as:(i) Determining the fate of the released species in the environment e.g. locations for bioaccumulation.(ii) Further degradation mechanisms once released into the environment.(iii) Impact of the released species on the environment e.g. evidence for biotoxicity.Predicted Outcomes:The project will provide an understanding for the potential release of organic material and metallic ions into the environment. This may enable ECCA members to formulate improved organic coatings with reduced environmental impact which will maintain the competitive position of the products in the European market.