Manufacture of ultrahigh‐modulus poly(oxymethylenes) by die drawing

A stable experimental die drawing process has been operated for poly(oxymethylene) over a range of temperature. Rods possessing room‐temperature Young's moduli up to 23 GPa were produced using a homopolymer grade, the values obtained from a copolymer being somewhat lower. This compares favorably with the best modulus achieved by hydrostatic extrusion but is rather lower than that produced by conventional drawing; reasons for this are discussed. A stable die drawing process has also been operated for glass fiber‐reinforced poly(oxymethylene), but extensive macroscopic void formation occurred in the products under all conditions, reducing their potential for practical application.