PLA生物降解聚酯材料的制备及降解性能的研究OA

Nanocellulose(CNC)was carboxylated and then introduced into polylactic acid(PLA)matrix.The effects of carboxylated nanocellulose(CNC-C)and CNC-C doping amount on the mechanical properties,phase structure,crystallinity and degradation properties of CNC-PLA composite polyester were studied.The results showed that,the hydrophilicity of CNC was improved after carboxylation,whose water contact angle was decreased from 73.5° to 46.4°.The infrared spectrum showed that CNC-C and PLA formed composite films by physical blending.The addition of CNC-C made the fracture mode of the composite films change from brittle fracture to ductile fracture.The tensile strength and fracture elongation of 3%CNC-C/PLA composite film both reached the maximum values of 40.8 MPa and 5.5%,and the cold crystallization temperature(Tc)of this composite film was of the minimum value(114.5℃),and its crystallinity reached the maximum value of 50.6%.The CNC-C introduced improved the degradability of the composite film.The weight loss of 3%CNC-C/PLA composite film was 1.71%after degradation at 25℃for one week,and it was 53.5%after degradation at 100℃for one week,indicative of excellent biodegradability and mechanical properties.