功能化纳米纤维素复合PLA/PBAT薄膜的制备及性能

Preparation and properties of functionalized nanocellulose PLA/PBAT composite film

摘要:

以γ-氨丙基三乙氧基硅烷（KH550）作为改性剂对纤维素纳米纤维（CNF）进行功能化改性，并使用聚丙二醇（PPG）对改性后的CNF进行包覆，制备CNF-PPG纳米粒子。将其作为填料加到聚乳酸（PLA）/聚己二酸/对苯二甲酸丁二醇酯（PBAT）聚合物基体中，使用溶液浇铸法制备PLA/PBAT/CNF-PPG复合薄膜。通过FTIR、XPS、SEM、DSC、TG等对薄膜进行了表征，探讨了PLA与PBAT的比例以及加入CNF-PPG纳米填料对薄膜机械强度、热稳定性、阻隔性能的影响。结果表明，PLA/PBAT薄膜比纯PLA薄膜有更高的韧性和热稳定性，当m(PLA)∶m(PBAT)=90∶10时，加入10%（以PLA/PBAT的质量为基准，下同）的CNF-PPG纳米填料，复合薄膜的拉伸强度达到33.38 MPa，断裂伸长率为39.97%。与纯PLA相比，复合薄膜最终降解温度从394 ℃提高到435 ℃；水蒸气和氧气渗透系数分别为4.98×10-14 g·cm/cm2·s·Pa和8.86×10?14 cm3·cm/cm2·s·Pa，与纯PLA相比，减少了33.6%和23.5%。

Abstract:

CNF-PPG nanoparticles were prepared by functionalized cellulose nanofibers (CNF) with γ-aminopropyltriethoxysilane (KH550) as a modifier and using polypropylene glycol (PPG) to coat the modified CNF. CNF-PPG were added as fillers to a polylactic acid (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) polymer matrix and PLA/PBAT/CNF-PPG composite films were prepared using the solution casting method. The films were characterized by FTIR, XPS, SEM, DSC and TG, and the effects of the ratio of PLA to PBAT and the addition of CNF-PPG nano-fillers on the mechanical strength, thermal stability and barrier properties of the films were investigated. The results showed that the PLA/PBAT films had higher toughness and thermal stability than the pure PLA films. When m(PLA):m(PBAT)=90:10, the tensile strength of the composite films reached 33.38 MPa and the elongation at break was 39.97% with the addition of 10% (based on the mass of PLA/PBAT, as below) of CNF-PPG nano-fillers. Compared with pure PLA, the final degradation temperature of the composite film was increased from 394 ℃ to 435 ℃; the water vapor and oxygen permeability coefficients were 4.98×10-14 g·cm/cm2·s·Pa and 8.86×10?14 cm3·cm/cm2·s·Pa, which were reduced by 33.6% and 23.5% compared with pure PLA, respectively.