Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou
General Project of Natural Science Foundation of Guangdong Province(2021A1515012334)
以γ-氨丙基三乙氧基硅烷（KH550）作為改性劑對纖維素納米纖維（CNF）進行功能化改性，并使用聚丙二醇（PPG）對改性后的CNF進行包覆，制備CNF-PPG納米粒子。將其作為填料加到聚乳酸（PLA）/聚己二酸/對苯二甲酸丁二醇酯（PBAT）聚合物基體中，使用溶液澆鑄法制備PLA/PBAT/CNF-PPG復合薄膜。通過FTIR、XPS、SEM、DSC、TG等對薄膜進行了表征，探討了PLA與PBAT的比例以及加入CNF-PPG納米填料對薄膜機械強度、熱穩定性、阻隔性能的影響。結果表明，PLA/PBAT薄膜比純PLA薄膜有更高的韌性和熱穩定性，當m(PLA)∶m(PBAT)=90∶10時，加入10%（以PLA/PBAT的質量為基準，下同）的CNF-PPG納米填料，復合薄膜的拉伸強度達到33.38 MPa，斷裂伸長率為39.97%。與純PLA相比，復合薄膜最終降解溫度從394 ℃提高到435 ℃；水蒸氣和氧氣滲透系數分別為4.98×10-14 g·cm/cm2·s·Pa和8.86×10?14 cm3·cm/cm2·s·Pa，與純PLA相比，減少了33.6%和23.5%。
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.