Polymer characterization: A typical copolyamide system

Abstract

Abstract A characterization scheme for small‐scale evaluation of fiber‐forming polymers is presented. Tests are described for bulk polymer (visual observations, toughness, viscosity number, polymer melt temperature, and solubility), films (visual observations, toughness, water absorption, glass transition temperature, and crystallinity), and fibers (tenacity, elongation, initial modulus, compliance ratio, tensile recovery, work recovery, fiber stick temperature, zero strength temperature, crystalline melting point, orientation, and crystallinity). The copolyamide system poly(tetraethylene adipamide‐ co ‐hexamethylene sebacamide) was evaluated over the whole composition range by this scheme. In general, maxima or minima were obtained at an intermediate composition for the properties studied. The point of greatest copolymer effect, however, was found to depend upon the specific property studied. Water absorption and glass transition temperature appeared to be more nearly linear functions of composition.