数字印刷废纸纤维增强聚乳酸复合薄膜的性能研究

以数字印刷废纸、聚乳酸（PLA）为原料，采用熔融混炼、热压成形的工艺制备得到废纸纤维/PLA复合薄膜，探究了不同废纸纤维添加量和不同改性剂对复合薄膜性能的影响。分别加入硅烷偶联剂γ-缩水甘油醚氧丙基三甲氧基硅烷（KH560）、乙烯基三甲氧基硅烷（A171）、异丙基三（二辛基焦磷酸酰氧基）钛酸酯（TMC201）及木聚糖酶，对废纸纤维进行改性处理，研究了改性前后复合薄膜的力学性能、不透明度、化学结构及热稳定性等。结果表明，当废纸纤维质量分数为25%时，复合薄膜抗张强度最佳，达21.6MPa，相较于纯PLA薄膜提高了94.7%；当废纸纤维质量分数为20%时，其不透明度增加至95.5%；废纸纤维经改性处理后，复合薄膜抗张强度均有不同程度的提升，其中KH560的改性效果最佳，复合薄膜（废纸纤维质量分数25%）抗张强度达24.7 MPa，相较于改性前提升了14.4%；改性处理并未对复合薄膜的不透明度和热稳定性产生影响。

Study on Performance of Digital Printing Waste Paper Fiber-reinforced PLA Composite Films

Waste paper fiber/PLA composite films were prepared from digital printing waste paper and polylactic acid （PLA） by melt blending and hot press molding. The effects of different waste paper fiber additions and different modifiers on the performance of composite films were investigated by adding silane coupling agents， including γ-glycidyl ether oxypropyltrimethoxysilane （KH560）， vinyltrimethoxysilane （A171）， isopropyltris（dioctylpyrophosphoryloxy）titanate （TMC201） and xylanase， respectively. The mechanical properties， opacity， chemical structure and thermal stability of composite films before and after modification were investigated. The results showed that the tensile strength of the composite films was the best when the mass fraction of waste paper fiber was 25%， reaching 21.6 MPa， which was 94.7% higher than that of the pure PLA film. The opacity of the waste paper fiber increased to 95.5% when the mass fraction of waste paper fiber was 20%. Moreover， the tensile strengths of the composite films were all improved to different degrees after the modified treatment of the waste paper fiber， among which the modification of KH560 was the best， with the tensile strength of the composite films （the mass fraction of waste paper fiber of 25%） reaching 24.7 MPa， an increase of 14.4% compared to the non-modified composite films. The modified treatment did not affect the opacity and thermal stability of the composite films.