ABSTRACT
The extent to which thermoplastics have succeeded in replacing the more tradi tional building materials, such as wood, glass, and metal, has been due largely to the favorable balance of properties offered by plastics. Although low density and ease of fabrication are typical selling points for the use of thermoplastics, the ability of many thermoplastics to resist failure when loaded at impact speeds, commonly referred to as the “ toughness” or “ impact strength” of the material, is often one of their most desirable characteristics. Indeed, technology for the provision of toughness in thermoplastics has been practiced nearly as long as these materials have been manufactured.
