The Effect of Aging on the Mechanical Strength of Polyvinyl-Chloride(PVC) Sheet Thermoformed by Uniaxial Stretching
Akihisa TSUKAMOTO, Hirotaka ARITA and Yukuo NANZAI
Abstract:To study the effect of aging on the mechanical strength of uniaxially thermoformed thermoplastics, we carried out uniaxial tensile test of thermoformed poly(vinyl chloride) (PVC) aged for varios time periods. The ductility of thermoformed specimens in the direction transverse to that of stretching was reduced by aging. At a high elongation ratio, the ductility in the direction of stretching was not reduced by aging. Thus, the ductility is probably dominated by not only the relaxation from the quenched structure but also the relaxation of strongly stretched polymer chains. These data bring us to predict the thermoforming condition avoiding the reduction of ductility for aging. Key Words:Polyvinyl-chloride (PVC), Thermoforming, Uniaxial stretching, Aging, Tensile ductility