摘要
采用60Coγ射线对聚-L-乳酸(Poly(L-lactic acid),PLLA)进行辐照。研究了在真空、氮气、空气和氧气气氛下吸收剂量对PLLA粘均分子量、结晶行为以及热失重的影响,并采用粘度法、差示扫描量热法(Differential scanning calorimeter,DSC)、偏光显微镜(Polarized microscope,POM)、热重分析法(Thermogravimetry analysis,TGA)对其进行了表征。结果表明,PLLA粘均分子量随吸收剂量的增加而下降,真空辐照的PLLA粘均分子量最高;在吸收剂量6～40kGy范围内,辐照提高PLLA的结晶度和结晶速率;在吸收剂量6～40kGy范围内,辐照后PLLA的TGA曲线移向高温。6kGy的吸收剂量,PLLA在氧气辐照气氛下热失重低于氮气辐照气氛。
Poly （L-lactic acid） was irradiated by γ-rays. The effects of absorbed dose on viscosity average molecular weight, crystallization and thermal weight loss in irradiated condition under vacuum, nitrogen, air and oxygen were investigated, which were characterized by using ubbelohde viscometer, differential scamming calorimeter （DSC） polarized microscope and thermogravimetry analysis （TGA）. Viscosity average molecular weight of PLLA decreases with increment of absorbed dose and viscosity average molecular weight of PLLA irradiated in vacuum is highest among the different irradiated condition at same absorbed dose. Both degree and rates of crystallization increase with increment of absorbed dose and TGA curves of PLLA irradiated under vacuum or nitrogen are shifted towards higher temperature compare with un-irradiated sample at the absorbed dose from 6-40kGy. The weight loss of PLLA irradiated under oxygen is lower than that under vacuum at absorbed dose of 6kGy.
出处
《辐射研究与辐射工艺学报》
CAS
CSCD
北大核心
2008年第6期326-330,共5页
Journal of Radiation Research and Radiation Processing
基金
科技部国际合作重点计划(DFA2006DFA53450)
四川省青年科技基金(08ZQ026-094)资助
关键词
聚-L-乳酸
Γ-辐照
结晶
热稳定性
Poly （L-lactic acid）, γ-rays irradiation, Crystallization, Thermal stability
