Degradation of adhesives

Adhesives are based on polymers and these are susceptible to attack by oxyg en, ultraviolet radiation, and heat, although adherends that are impermeabl e or opaque will give some protection against oxygen and ultraviolet radiat ion. Such degradation can be reduced by the use of additives and can be mon itored by instrumental methods of chemical analysis. Weighing is widely use d to monitor the interaction of adhesives and sealants with fluids such as plasticisers and water. Plasticisers can alter properties by either leaving or invading an adhesive substance and water may alter properties by decrea sing the glass transition temperature, by chemical reaction, or by forming microcracks. PRCPA/1461. (C) 1998 The Institute of Materials.