Journal of Applied Polymer Science, Vol.99, No.3, 835-844, 2006
Micro-structure and characteristics of highly oriented polyoxymethylene obtained by press and biaxial drawing
The physical structure of oriented polyoxymethylene (POM) drawn in two steps by press drawing and subsequent simultaneous biaxial drawing was studied. The degree of crystallinity, the orientation, and the tensile modulus depending on draw ratio were analyzed. By the press drawing method, the draw ratio reached 6.0, the tensile modulus was 4.5 GPa, and the degree of crystallinity decreased from 70% to 65%. By the two-step drawing of press drawing followed by subsequent simultaneous biaxial drawing, the tensile modulus reached 11 GPa when the draw ratio was 14 times, and the degree of crystallinity increased from 71% to 76-80%, but it did not depend on the draw ratio, and showed effectively a constant value (average 77%). The physical structural properties, such as the degree of crystallinity, the orientation of the crystal, and the lamella structure, were analyzed by SEM, X-ray diffraction, and other methods. (c) 2005 Wiley Periodicals, Inc.