Molecular weight dependence of tensile properties in poly(vinyl alcohol) fibers

Abstract

A method was developed to study the dependence of fine structure of poly(vinyl alcohol) (PVA) fibers on the degree of polymerization and the effect of moisture absorption on the its mechanical properties. The wet samples were prepared to measure the tensile properties by using an Instron tensile tester. The X-ray diffraction intensity curves were used to find the degree of crystalline orientations on the plane for the yarn fixed in a folder. The results showed that the Young's modulus and tensile strength of a PVA fiber decreased with moisture absorption whereas the tensile elongation increased. It was also found that the polymer was hydrophilic due to the existence of OH groups.