Radiation and Photochemical Methods for Synthesizing Novel Bioactive Polymers for Medical Applications

Abstract

The use of ionizing radiation and ultraviolet to synthesize polymers possessing novel structures is becoming increasingly important in a wide variety of fields. The concept is particularly useful in grafting reactions where specific groups can be incorporated into polymers in a one-step process for the subsequent attachment of biologically active molecules, such as enzymes, etc. In all of this work, the ability to lower the exposure of the polymer system to radiation during the grafting reaction is valuable for both the ionizing radiation and the photochemical systems. The development of additives for this purpose has been extensive over the past ten years. Thus, inorganic acids, salts and poly-functional monomers in additive amounts (1%) can enhance UV and radiation grafting of monomers to backbone polymers. In this paper, the effect of specific organic compounds as additives for increasing the grafting yields is discussed and compared with the enhancement properties of earlier additives. Styrene in methanol has been used as the representative monomer with the polyolefins and cellulose as the typical backbone polymers in the presence of ionizing radiation and ultraviolet light. The mechanism of the additive effect and its possible use in the synthesis of polymers capable of immobilizing bioactive materials is discussed.