Improvement of heat stability of poly(l-lactic acid) by radiation-induced crosslinking
2005; Elsevier BV; Volume: 46; Issue: 13 Linguagem: Inglês
10.1016/j.polymer.2005.03.088
ISSN1873-2291
AutoresHiroshi Mitomo, Ayako Kaneda, Trần Minh Quỳnh, Naotsugu Nagasawa, Fumio Yoshii,
Tópico(s)Carbon dioxide utilization in catalysis
ResumoPoly(l-lactic acid) (PLLA) has poor heat stability above its glass transition temperature (Tg∼60 °C). To improve its softing above Tg, PLLA was mixed with small amount of crosslinking agents and irradiated with various irradiation doses to introduce crosslinking between polymer chains. The most effective agent for radiation crosslinking was triallyl isocyanurate (TAIC). For melt-quenched PLLA, it was found that the most optimal conditions to introduce crosslinking were around 3% of TAIC and the irradiation dose of 50 kGy. The typically crosslinked PLLA showed very low crystallinity because of wide formation of molecular chain network that inhibited molecular motion for crystallization. Notable heat stability above Tg was given by annealing of PLLA samples. Enzymatic degradation of PLLA was retarded with introduction of crosslinks.
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