聚乳酸/纳米SiO_2共混物的热性能

以两种含有不同功能团的纳米SiO2对聚左旋乳酸(PLLA)进行了共混改性,从而提高了PLLA的性能。在纳米SiO2的质量分数为0.5~5%范围内,PLLA与之是相容的,其中含有—NH2功能团的RNS型纳米对PLLA的Tg有一定的影响,加入质量分数为5%的RNS型纳米SiO2后,PLLA的Tg降至52℃。由于RNS纳米SiO2中的—NH2与PLLA分子链中的—C=O形成了弱的氢键,因此在相同质量分数下,对PLLA热稳定性的影响要高于含—CH3功能团的DNS纳米SiO2,质量分数为5%的纳米SiO2与PLLA共混后,PLLA/RNS纳米SiO2共混物的热失重起始温度为370℃,而PLLA/RNS纳米SiO2共混物的则为365℃。

Thermal Properties of Poly(L-lactide)/nano SiO_2 Blends

The thermal stability of Poly(L-lactide)(PLLA)was improved by blending with 2 kinds of nano SiO_2 with-NH_2(RNS)and-CH_3(DNS)functional group.The blending experiments were carried out with the mass fraction of nano SiO_2 from 0.5% to 5%.DSC and FTIR show that 2 kinds of nano SiO_2 were compatible with PLLA in the experimental scale.RNS nano SiO_2 with-NH_2 functional group can decrease the T_g of PLLA.The T_g of PLLA / RNS nano SiO_2 blend was 52℃ when the mass fraction of RNS nano SiO_2 was_5 %.The thermal stability of PLLA / RNS nano SiO_2 blends were higher than that of PLLA / DNS nano SiO_2 blends at the same mass fraction of nano SiO_2.The thermal degradation onset temperature of PLLA / RNS nano SiO_2 blend and PLLA / DNS nano SiO_2 which mass fraction of nano SiO_2 were 5% were 370℃ and 365℃ respectively.