三醋酸甘油酯增塑聚乳酸共混体系热力学及动态力学性质

The effects of plasticizers TAc on the thermal properties and dynamic mechanical of poly(Lactic acid)

用三醋酸甘油酯(TA c)增塑聚乳酸(PLA),研究了TA c对PLA力学性能的影响。当塑化剂添加到15%之后抗张强度从64M Pa下降到29.9M Pa,断裂伸长率同时从5.6%升高到243.1%,可以达到吹膜所要求的性质。用DSC和DM A研究了该共混体系的相容性,观察到随着TA c含量的增大,线性降低了PLA的Tg和Tm,并且塑化剂提高了分子链的迁移性,也使得体系的结晶度增大。在塑化剂含量为25%时,PLA已经被塑化剂所饱和,继续添加塑化剂可能会导致两相分离。

Poly （lactic acid） （PLA） was blended with Triacetine because plasticizer had solubility parameters closed to that of PLA. The blends had good mechanical properties, tensile strength decreased from 64MPa to 29. 9MPa, and elongation at break increased from 5.6% to 243. 1%. The blends were also analyzed by means of dynamic mechanical analysis and differential scanning calorimetry to investigate the misbility of the blends. Triacetine proved to be effective as plasticizers when blended with PLA. The glass transition temperature ot PLA decreased linearly as the plasticizer content was increased. At 25wt% content, the PLA seemed to be saturated with plasticizer and the blends tended to phase separate when more plasticizer was added. The presence of the plasticizers induced an increased crystallinity by enhancing the molecular mobility.