Revitalizing Used Automotive Rubber: Silicone Rubber Composites

科学家越来越有义务发展可持续的进程。在仅仅使用几年之后，否则高价值、有弹性的汽车轮胎橡胶通常会被燃烧、热解成低价值产品、部分脱硫化或转化为碎屑；将不可再生石油一次或二次用于低价值产品的过程是不可持续的。有机硅聚合物在许多市场上都受到追捧，因为它们具有吸引人的特性，包括与玻璃和金属表面的附着力，对温度波动的灵活性/稳定性以及在环境中的可降解性；这些是有机替代品所不能满足的。我们已经发现了一种激活从汽车轮胎中回收的橡胶屑表面的方法，使其能够被纳入有机硅弹性体中，以制造高价值的复合材料。复合材料的成本比普通的有机硅低得多，弹性体表现出增强的增强性，在使用寿命结束时，复合材料很容易回收为有机硅和回收的碎屑，可以纳入新的复合材料。这笔拨款将确定可用于增强有机硅弹性体的廉价橡胶屑的类型和数量，从而能够针对适当市场进行大规模生产。配方目标包括：1)用我们的支持组织Siltech提供的不同硅酮前体控制碎屑表面；2)选择合适的硅酮固化技术，使弹性体可用于山地车零件和商业密封胶（如建筑玻璃）等产品；3)量化复合材料制造的工艺变量，并将配方与所产生的物理性能相关联。在这些应用中，含有橡胶屑的硅酮复合材料的低成本和高性能使其能够轻松进入现有市场。复合材料的完全可回收性将被证明允许产品的高可持续性得分。基于加拿大知识产权的硅橡胶复合材料将允许加拿大公司（硅橡胶/轮胎回收）进入新市场。

Scientists increasingly have an obligation to develop sustainable processes. After only a few years use, otherwise high value, resilient automotive tire rubber is typically burned, pyrolyzed to low value products, partly devulcanized, or converted to crumb; the process of taking non-renewable petroleum and using it once, or a second time in low value products, is not sustainable. Silicone polymers are sought after in many markets because of their attractive properties, including adhesion to glass, and metal surfaces, flexibility/stability to temperature fluctuations, and degradability in the environment; these are not met by organic alternatives. We have discovered a route to activate the surface of rubber crumb recovered from automobile tires to permit it to be incorporated in silicone elastomers to make high value composites. The cost of the composite is much lower than normal silicones, the elastomers exhibit enhanced reinforcement and, at end of life, the composite is readily recycled to silicones and recovered crumb that can be incorporated in new composites.This grant will determine the type and quantity of inexpensive rubber crumb that can be used to reinforce silicone elastomers to enable the development of large scale production that can be targeted to appropriate markets. Formulation objectives include: 1) control of the crumb surface, with different silicone precursors provided by our supporting organization Siltech, 2) selection of appropriate silicone cure technologies giving elastomers that can be utilized, for example, in products like mountain bike parts and commercial sealants (e.g., construction glazing), and 3) quantification of the process variables for composite creation, and correlating formulation to resulting physical properties.In these applications the low cost and high performance of silicone composites that contain the rubber crumb enables facile entry into existing markets. The complete recyclability of the composites will be demonstrated to permit a high sustainability score for the product. The rubber-in-silicone composite, based on Canadian IP, will allow Canadian companies (silicone/tire recycling) to enter new markets.