Additives, nanocomposites, and barrier coatings

Abstract

Material use is often governed by the properties it brings to an application, but in some cases those desirable properties are rapidly degraded by their intended use environment. Heat, abrasion caused by part-on-part wear, and particulate impact can damage material properties, especially polymer-fiber-reinforced composites. To ensure that the benefits of polymer composites can be utilized in these extreme environments, protection is needed. The simplest form of protection is the use of additives to the polymer matrix, such as antioxidants, thermal stabilizers, and flame retardants. Of newer interest is the use of nanocomposite technology, which provides enhanced thermal and mechanical durability, which sometimes brings multifunctional performance to the composite. Barrier coatings represent an engineering solution to protect the composite part, but newer research focuses on incorporation of the barrier coating during composite fabrication so that the protection is engineered to be a covalently bound part of the polymer rather than a post-fabrication add-on coating produced via painting or adhesive bonding. This chapter provides a survey of the broad range of protection solutions available for composites, with an emphasis on approaches that yield thermal and/or abrasion protection in polymer composites.