Effect of Crystalline and Amorphous Structures on Biodegradability of Poly(Tetramethylene Succinate)

Abstract

The effect of orientation in the amorphous and crystalline regions on the biodegradability of PTMS [poly(tetramethylene succinate)] was studied using the amorphous orientation function, birefringence, and crystallinity. The crystalline and amorphous intrinsic lateral sonic moduli, E ⁰_t,c and E ⁰_t,am , were 2.61 × 10³ and 0.41 × 10³ MPa, respectively. Using the data on birefringence, crystalline and amorphous orientation function (f _∈ and f _am), crystallinity, and sonic modulus of the oriented PTMS fibers, the intrinsic birefringence of the crystalline (Δ ⁰_c ) and amorphous (Δ ⁰_am ) regions were evaluated to be 0.0561 and 0.0634, respectively. The biodegradabilities of oriented PTMS films were reduced as the elongation increased, i.e., the amorphous orientation increased. At low elongation (100 and 150%), however, biodegradabilities remained unchanged when the degradation test was performed in activated sludge, which was attributed to the amorphous orientation occurring even at 100% elongation, though the amorphous orientation direction was perpendicular to the fiber axis.