Next-generation super varnishes via reversible de-activation radical polymerization

涂料是汽车和航空航天工业中不可或缺的材料。在这个竞争激烈的领域，C&D Aerospace Canada Co. （C&D Zodiac Inc.的子公司）认为开发自己的清漆涂层配方至关重要：一种超级清漆。明显的“必备”性能包括抗开裂、防收缩、高抗燃性和对木材基材的附着力。此外，涂层溶液必须适合喷涂技术，并且必须具有延长的保质期。通过我们之前的合作，我们开发了一种树脂含量高（30%重量）但粘度很低的配方，从而降低了挥发性有机化合物（VOC）含量。它还将几种特性结合到一个分子中。除了满足最初的要求外，开发超级清漆的下一步将是开发更环保的工艺，进一步减少VOC（从而提高抗燃烧性能）和自修复特性。更环保的工艺不仅包括通过水性涂料工艺减少VOC，还包括尽可能多地使用可持续资源的单体。使用可逆去活化自由基聚合（RDRP）可以更精细地控制微观结构，并且易于在分散的水性体系中聚合。自我修复性能是理想的，因为材料可以恢复和关闭任何表面损伤/缺陷，从而消除了昂贵的刮擦去除程序。RDRP在自修复材料中的应用是前沿的，最近才有报道强调这种新颖的组合。结合所有这些特性，这些新型树脂涂层的工程设计（多种涂层、热处理、对流干燥）将随之而来，以优化材料性能和工艺时间，从而轻松实现工业应用。

Coatings are integral for materials used in the automotive and aerospace industries. In this competitive sector, C&D Aerospace Canada Co. (subsidiary of C&D Zodiac Inc.) considers it vital to develop their own varnish coating formulations: a super varnish. Obvious "must-have" properties include resistance to cracking, prevention of shrinkage, high anti-flammability and adhesion to wood substrates. Further, the coating solution must be amenable to spraying techniques and must have an extended shelf-life. Through our previous interactions, we have developed a formulation that has high resin content (30% be weight) but has very low viscosity, thereby reducing the volatile organic content (VOC). It also combines several properties into one single molecule. In addition to meeting the initial requirements, the next step towards the development of a super varnish would be to develop greener processes with further reduction in VOC (which leads to improved anti-flammability properties) and self-healing characteristics. Greener processes includes not only reduction in VOC via water-borne coating processes, but also incorporating monomers from sustainable resources as much as possible. The use of reversible de-activation radical polymerization (RDRP) enables finer control of microstructure plus the ability to be readily polymerizable in dispersed aqueous systems. Self-healing properties are desirable, as materials that revert and close any surface damage/defect eliminates costly scratch-removal procedures. The application of RDRP to self-healing materials is cutting-edge, with reports only relatively recently highlighting this novel combination. With the incorporation of all these features, engineering of these novel resin coatings (multiple coatings, heat treatments, convective drying) will ensue to optimize material properties and process time, leading to a facile industrial implementation.