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

ポリ乳酸とポリ(ブチレンテレフタレート--アジペート)ブレンドの放射線橋かけと力学的性質

Sarath Kumara, P. H.*; 長澤 尚胤; 八木 敏明; 玉田 正男

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

ポリ乳酸(PLA)に生分解性芳香族ポリエステルであるポリ(ブチレンアジペート・テレプタレート)(PBTA)をブレンドし、橋かけ剤であるトリアリルイソシアヌレートを添加して放射線橋かけを行うことにより。PLA/PBTAブレンド体の熱変形性の抑制だけでなく、力学的性質の改善にも成功した。PBTAとのブレンドと電子線照射による橋かけ構造導入により、PLAの融点以上で形状を保持できるうえ、室温域で柔軟さを付与できることを見いだし、産業応用への道筋をつけた。

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.