Production of ultrahigh modulus polyoxymethylene by drawing under dielectric heating

A tensile drawing process under dielectric heating has been developed for polyoxymethylene. The influence of ambient temperature, electric field strength, and strain rate on the maximum draw ratio and the tensile modulus has been examined. Tubes possessing tensile moduli up to 63GPa were produced by the new drawing technique. It is speculated that the achievement of such ultrahigh moduli is due to the fact that the stress by drawing is used effectively to orient the molecular chains in the noncrystalline regions and at defect regions within the crystal lamellae. This is because these regions are heated to higher temperatures than the crystalline regions during dielectric heating.