Design of next-generation automotive corrosion protective coatings by improving inhibitor transport properties

保护涂料行业正在应对这一挑战，以找到一种成功的材料替代有毒防腐剂。欧盟已将铬(VI)的使用指定为2019年的“日落”日期，之后将禁止使用。现在迫切需要找到新的、环境可接受的防腐技术，使其具有同等或更好的保护能力。该公司与汽车涂料公司巴斯夫汽车公司合作，开发新的防腐技术。目前的技术水平部分是以磷酸盐为基础的，而且仍然是有限的；这导致了人们对开发智能释放颜料的极大兴趣，在智能释放颜料中，腐蚀抑制物种被存储，并仅在存在侵蚀性腐蚀诱导剂的情况下按需释放。此外，还需要改进缓蚀剂物种从涂层的主体到具体需要它们的区域的传输(例如，暴露在底层金属的缺陷)。目前，只有来自缺陷附近涂层的有限数量的缓蚀剂可用于保护暴露的金属。通过在涂层内引入远程渗流网络，人们认为加强缓蚀剂到含有缺陷的区域的传输可以在暴露的金属处产生显著更有效的腐蚀抑制，从而提供技术的增强效率。研究工程师将：-使用当前技术水平的基于磷酸盐的颜料和新型智能释放离子交换颜料，负载各种缓蚀剂种类，来研究对渗透性涂层缺陷的腐蚀抑制效率。-通过改变涂层内所讨论的颜料负载量进行详细研究，评估对缓蚀剂释放速度和随后的缺陷‘愈合’的影响。-评估新的缓蚀剂输送系统，如纳米管储存库、离子交换树脂和矿物，以及导电聚合物网络，作为在保护有机涂层内引入缓蚀剂颜料的远程渗流网络以输送到缺陷位置的手段。-评估缓蚀剂物种从已开发的、优化的系统影响腐蚀驱动的有机涂层失效的机理，即由于渗透缺陷附近的阳极破坏和/或阴极剥离引起的脱附。这项工作的主要推动力是识别和开发具有重要技术意义的轻合金表面的下一代保护涂层，通常是铝和可能的镁汽车合金，尽管性能最好的技术也可以应用于钢的保护。该计划将利用集团内先进的电化学扫描技术方面的杰出专业知识，结合高通量方法，以系统的方式量化涂层技术的保护效率，提供对腐蚀抑制过程的机械理解。识别这些机理将使新的、更有效的缓蚀技术的开发成为可能，这些技术可以并入有机涂层系统。

The protective coatings industry is responding to the challenge to find a successful materials substitution for toxic anti-corrosion agents.Chromium (VI) use has been assigned a "sunset" date of 2019 by the European Union, after which its use will be banned. There is now an urgent need to identify new, environmentally acceptable corrosion inhibitive technologies showing equivalent, or better protective capability.The collaboration is in conjunction with the automotive coatings company, BASF Automotive, to develop new corrosion inhibitive technologies. The current state of the art technology is partially phosphate-based, and remains limited; this results in significant interest in exploiting the properties of intelligent-release pigments, in which corrosion inhibitive species are stored and only released "on demand" in the presence of aggressive corrosion-inducing agents. Furthermore, there is also a need to improve transport of the inhibitor species from the bulk of the coating, to the areas where they are specifically required (e.g. defects where the underlying metal is exposed). Currently, only a finite quantity of inhibitor originating from the coating in the immediate vicinity of the defect may be available to protect exposed metal. By introducing long-range percolation networks within the coating, it is thought that enhanced transport of corrosion inhibitor to defect-containing regions can produce significantly more effective corrosion inhibition at the exposed metal, as such providing enhanced efficiency of the technology.The Research Engineer will:- Investigate the efficiency of corrosion inhibition at penetrative coating defects using current state of the art phosphate-based pigments and novel smart-release ion-exchange pigments, loaded with various corrosion inhibitive species.- Carry out a detailed study through variation of discussed groups of pigment loadings within a coating, to evaluate the effect on speed of inhibitor release and subsequent defect 'healing'.- Assess novel inhibitor delivery systems such as nanotube reservoirs, ion exchange resins and minerals, and conducting polymer networks, as a means of introducing a long-range percolation network for inhibitor pigment within the protective organic coating for delivery to the defect site.- Evaluate how the long-range transport of inhibitor species from a developed, optimised system influences the mechanism of corrosive-driven organic coating failure i.e. due to de-adhesion originating from anodic undermining and/or cathodic disbondment in the vicinity of a penetrative defect.The main impetus of the work is to identify and develop next-generation protective coatings for technologically important light alloy surfaces, typically aluminium and possibly magnesium automotive alloy grades, although the best performing technologies may also be applied to the protection of steel. This program will exploit outstanding expertise in advanced electrochemical scanning techniques within the group, coupled with high throughput methodologies to quantify protection efficiency of the coating technology in a systematic fashion, providing mechanistic understandings of the corrosion inhibition processes. Identifying these mechanisms will enable the development of new, more effective corrosion inhibition technology that can be incorporated into organic coating systems.