聚乙二醇改性聚乳酸/乙酰柠檬酸三丁酯复合薄膜的结构及性能

Structure and Properties of Poly(lactic acid)/Acetyl Tributyl Citrate Blend Films Modified with Poly(ethylene glycol)

以聚乳酸(PLA)为基材、乙酰柠檬酸三丁酯(ATBC)为增塑剂、聚乙二醇(PEG)为增韧剂采用溶液共混法涂覆制备PLA复合薄膜。采用红外吸收光谱、热分析、X射线衍射、扫描电子显微镜及拉伸测试表征PLA复合薄膜的结构和性能。结果表明,适量的PEG改性PLA/ATBC复合薄膜后,使其拉伸强度从29.52MPa增加到33.40MPa,断裂伸长率从262%增加到292%,薄膜的柔韧性得到增强;PEG的端羟基与PLA的羰基发生缔合反应形成氢键,提高了PLA/ATBC复合薄膜的热稳定性和结晶度;观察90d后的薄膜表面SEM图像,发现PEG改性后的PLA/ATBC复合薄膜表面没有龟裂纹的产生,延长了其使用寿命;加入微量的爽滑剂乙撑双硬脂酰胺(EBS)改善了PLA复合薄膜的相容性和加工性能。

Poly(lactic acid)(PLA)/acetyl tributyl citrate(ATBC)/poly(ethylene glycol)(PEG)blend films were prepared by solution blending,and their structure and properties were characterized by Fourier-transform infrared spectroscopy,thermal analysis,X-ray powder diffraction,scanning electron microscopy(SEM)and tensile experiments.The results indicated that the tensile strength increased from 29.52 MPa to 33.40 MPa and the elongation at break increased from 262%to 292%after the PLA/ATBC blend films were modified with a proper amount of PEG.As a result,the flexibility of the films was enhanced.The terminal hydroxyl groups in PEG could interact with the carbonyl of PLA to form hydrogen bonds,which improved the thermal stability and crystallinity of blend films.SEM micrographs demonstrated that there was no crack on the surfaces of the PLA/ATBC/PEG blend films after aging for 90 days,suggesting that the service lifespan of films was extended.Moreover,the compatibility and processability of blend films were improved with the addition of small amounts of N,N′-ethylenebis(stearamide).