聚乳酸基纤维素纳米晶体抗菌包装材料的制备及其性能研究

为改善聚乳酸(PLA)膜的力学性能、阻隔性能和抑菌性能,通过溶液浇铸法制备纤维素纳米晶体(CNC)和槐糖脂(SL)掺杂的PLA复合抗菌膜,探究SL含量(10%)不变时,CNC的含量对PLA/SL/CNC的力学性能、亲疏水性、水蒸气阻隔性和抑菌性能的影响。结果表明:PLA复合膜具有较好的透光性。CNC含量为8%时,CNC与PLA相容性较差。相比纯PLA,PLA/SL/CNC(6%)的拉伸强度高达68.6 MPa,提高93.8%;PLA/SL/CNC(6%)的韧性为36.5×10⁸J/m³,增加46%。PLA/SL/CNC(6%)水接触角为86°,具有疏水性。PLA/SL/CNC(6%)的水蒸气透过系数为2.4(g·cm)/(Pa·s·cm²),与纯PLA相比降低36.8%。PLA/SL/CNC(6%)与利斯特氏菌和金黄色葡萄球菌共培养24h,菌落数分别为0.8 lgCFU/mL和0.4 lgCFU/mL,具有较好的抑菌效果。

Preparation and Properties of Polylactic Acid Based Cellulose Nanocrystals Antibacterial Packaging Materials

In order to improve the mechanical properties, barrier properties and antibacterial properties of polylactic acid(PLA) films, cellulose nanocrystals(CNC) and sophorolipid(SL) doped PLA composite antibacterial films were prepared by solution casting method. The effects of CNC content on the mechanical properties, hydrophilicity, water vapor barrier properties and antibacterial properties of PLA/SL/CNC were investigated when the SL content(10%) was unchanged. The results show that the PLA composite membrane has good transparency. The compatibility between CNC and PLA is poor when CNC content is 8%. Compared with pure PLA, the tensile strength of PLA/SL/CNC(6%) is 68.6 MPa, which is increased by 93.8%;the toughness of PLA/SL/CNC(6%) is 36.5×10⁸ J/m³, which is increased by 46%. The water contact angle of PLA/SL/CNC(6%) is 86°. The water vapor transmission coefficient of PLA/SL/CNC(6%) is 2.4(g·cm)/(Pa·s·cm²),which is 36.8% lower than that of pure PLA. PLA/SL/CNC(6%) is co-cultured with Listeria monocytogenes and Staphylococcus aureus for 24 h, and the number of colonies was 0.8 lgCFU/mL and 0.4 lgCFU/mL, respectively, showing good antibacterial effect.