Viscoelastic and mechanical properties of poly(butyl acrylate-g-styrene) copolymers

Viscoelastic relaxations of four poly(butyl acrylate-g-styrene) copolymers were studied over a wide range of temperatures. The temperature location and apparent activation energy of the distinct relaxations found are discussed. A single relaxation associated with cooperative motion has been observed in the range of graft content analysed. In addition, the stress-strain behaviour of these graft copolymers was studied. Films of the copolymer samples were stretched at room temperature since the possible application as adhesives might take place at about room temperature. Some mechanical parameters have been estimated, such as elastic modulus, tensile strength and toughness. Moreover, microhardness has been measured and its relationship with other mechanical properties has been established. (C) 2001 Elsevier Science Ltd. All rights reserved.