Polymer Surface Modification

Surface modification as a technology has been employed in various ways for many years, however, the breadth and magnitude of its applications have grown significantly during the last decade. Much of this growth has been facilitated by the development and spread of rapid and reliable surface characterization techniques. And, as would be expected of a maturing field, the bulk of investigations are now turning to applications rather than a pure understanding. Publications in both the scientific literature and patents describe research on a diverse range of polymeric substrates and potential applications using a wide range of modification techniques. Methods include chemical, photochemical, and high-energy physical techniques to modify polymer surfaces. Searches were made of these methods as applied to the surface modification of polymeric materials of particular interest to the rubber industry. Chemical methods include reactions such as halogenation, addition, etching, and oxidation. Photochemical techniques include surface reactions such as oxidative and nonoxidative degradation, halogenation, and photografting. Physical methods include corona discharge, plasma, electron and ion beam treatments. The 1980's literature on these subjects is published in a variety of languages, including a number of informative review articles and books printed in English on various aspects of this subject. The subject of this review concentrates on the surface modification of polymeric materials of particular interest to the rubber industry by focussing largely on scientific literature published in English and patent literature published during this time period that describe interesting and useful surface chemistry on elastomer substrates and rubber articles containing polymers such as natural rubber, cis-polyisoprene, styrene-butadiene copolymer, nitrile rubber, silicone, etc, and fibers and fabric made from fiber-forming polymer materials such as aramid, nylon, polyester, and carbon fiber, and those techniques reported successful in altering their surfaces. For organizational simplicity, three basic categories are used: elastomers, fibers and others. The latter category refers to those substrates without specific, current application in the rubber industry, but which have interesting or novel scientific features. Restriction of interest to rubber-relevant materials greatly reduced the scope of this work, and the interested reader should be aware that a great deal of activity is to be found in the rigid plastic and, to a lesser extent, biopolymer industries.