Radiation-induced crosslinking and mechanical properties of blends of poly(lactic acid) and poly(butylene terephthalate--adipate)

Sarath Kumara, P. H.*; Nagasawa, Naotsugu; Yagi, Toshiaki; Tamada, Masao

Blends of poly(L-lactic acid) (PLLA) and poly(butylene terephthalate--adipate) (PBTA) were prepared at ratios of 50:50, 60:40, and 80:20 by melt blending in a Laboplastomill. Improved mechanical properties were observed in PLLA when it was blended with PBTA, a biodegradable flexible polymer. Irradiation of these blends with an electron beam (EB) in the presence of triallyl isocyanurate (TAIC), a polyfunctional monomer, did not cause any significant improvement in the mechanical properties, although the gel fraction increased with the TAIC level and dose level. Irradiation of the blends without TAIC led to a reduction in the elongation at break but did not show asignificant effect on the tensile strength. The elongation at break of PBTA was unaffected by EB radiation in the absence of TAIC.