7 - Surface Preparation of Thermoplastics, Thermosets, and Elastomers

Abstract

This chapter discusses the methods used for surface preparation of thermoplastics, thermosets, and elastomers. Thermoplastics, thermosets, and elastomers require surface treatment to remove contamination and prepare their surfaces for adhesion bonding. Both initial bond strength and bond durability are affected by the surface preparation technique. In recent times, new technologies have spurred the development of novel and unusual surface treatment techniques. These methods are often highly specialized and developed, around specific applications. Plasma treatment is effective for treating the surface of the majority of plastics. Ultraviolet zone (UVO) based method, can be used to oxidatively modify polymer surfaces. Electron spectroscopy for chemical analysis (ESCA) and contact angle results indicated that the treatment was effective on PE and a polyetheretherketone (PEEK). It produced changes in surface oxygen chemistry and free energy, which increased polarity and improved wettability of the surface. Gas plasma treatment is also very effective and is recommended for use with very complex geometric surfaces, which cannot be sanded or flame-treated adequately where very strong bonds are required.