Crystallization Behavior and Mechanical Properties of a Nylon -6, -6/6 and -12 Ter-Polyamide

Composition, tacticity and processing history can affect the morphology of semicrystalline polymers. Although homo-polyamides are a family of polymers well known for semicrystalline character, through copolymerization or multicomponent copolymerization significant changes in materials' crystalline and thermal properties can occur. Due to chain irregularities introduced by terpolymerization, differential scanning calorimetry shows RDG 114T, a commercial polyamide of nylon-6, -6/6 and 12, to have an atypically low T(subm) and exhibit interesting recrystallization behavior. Specifically, the polyamide is wholly amorphous upon cooling from the melt and since its T(subg) is about 20 degreesC (due to the presence of plasticizers) chain ordering is found to occur over time at room temperature. Since the polyamide's morphology is time dependent, the tensile properties of the polymer are alos found to vary with ambient aging. For instance, YOun't smoduli for an amorphous and 7-day room temperature annealed sample are 1.3 x 10(sup2) and 2.8 x 10(sup2) MPa, respectively. (Dept757)