HIGH-PERFORMANCE POLYAMIDE-6 AND BLENDS OF POLY(ETHYLENE-TEREPHTHALATE) AND POLY(BUTYLENE TEREPHTHALATE) THROUGH ULTRAQUENCHING

Polyamide-6 (PA6) and blends of poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT) characterized by amorphous initial structure and improved mechanical properties are obtained by means of an ultraquenching technique. In the case of polyamide-6, erasure of the structural memory is achieved by melt annealing above the equilibrium melting point. This procedure is applied in order to restrict the crystallization process. After quenching, further orientation of the amorphous polymers and annealing with fixed ends lead to a significant improvement of the mechanical properties. The tensile strength and elasticity modulus increase three to five times and the elongation at break decreases by half as compared with conventionally obtained polyamide-6, PET and PBT.