Anelastic Deformation of a Thermoplastic-Matrix Fiber Composite at Elevated Temperature; Part II: Time-Temperature Dependent Matrix Behavior

Abstract

The tensile deformation and failure behavior, dynamic mechanical proper ties and creep behavior of PACM-12 (DuPont, poly(bis 4-4' dicyclohexylmethane) n-dodecanediamide), a representative thermoplastic polymer for use as a matrix in ad vanced composites and as an engineering plastic, as a function of processing history are described. Although injection molded PACM-12 fails in a brittle fashion at room tempera ture, completely amorphous PACM-12 is ductile; the difference is attributed to variations in cooling in the interior of the samples due to sample thickness effects. Partially crystal line samples are brittle at room temperature, with all samples being ductile near and above Tg. A master creep curve for the partially crystalline samples can be obtained by horizontal shift alone.