LIMITS ON DRAWABILITY OF SEMICRYSTALLINE FLEXIBLE POLYMERS

We present a model study of the factors controlling the drawability of semicrystalline flexible polymers. Our approach focuses on the relati ve importance of the strength, sigma(h), of the attractive bonds betwe en chains in the amorphous phase and of that, sigma(a), of the same ch ains free of attraction forces. We find that drawability reaches its m aximum value when the ratio of the two strengths falls below a critica l value sigma(h)/sigma(a) similar or equal to 150. The maximum draw va lue itself is controlled by the crystallinity and by the entanglement density in the amorphous phase.