In bonding two materials that undergo unequal dimensional changes under such conditions as changing temperature, changing moisture content, or applied stress, it is necessary to use relatively soft, low-modulus adhesives, since these are inherently more capable of conforming to the changing configuration of the bonded joint than are rigid adhesives, thus minimizing shear stresses due to expansion and contraction. In general, thermosetting adhesives have better static-load properties, better high-temperature properties and better chemical resistance than do thermoplastic adhesives. On the other hand, thermoplastic adhesives are more than adequate for many applications and, in addition, frequently show better low-temperature properties than do thermosetting adhesives. -- AATA