利用废弃滤纸制备纳米纤维素/聚乙烯醇包装复合材料

Preparation of Disused Filter Paper Cellulose Nanofibers-reinforced PVA Composites

目的研究利用机械法处理废弃滤纸浆制备功能性包装复合材料的可行性。方法采用研磨和高压均质的方法,分别从未处理和乙酸预处理废弃滤纸浆中分离出2种不同尺寸的纤维素纳米纤丝（CNFs）,悬浮液抽滤成膜,并采用浸渍法制备2种CNFs/PVA复合膜,对其力学性能和透光率进行测试。结果通过场发射扫描电镜（SEM）观察,未处理滤纸浆的纤维素纤丝直径分布在300~500 nm之间,乙酸预处理后纤丝直径明显减小,主要分布在60~100 nm之间。乙酸预处理滤纸CNFs/PVA复合膜具有较好的力学性能和透明性,其中拉伸强度高达90.45 MPa,较PVA提高了201%,透光率为81.3%,较PVA降低10.3%。结论对2种方法制备的CNFs/PVA复合材料性能比较表明,经乙酸预处理后的滤纸CNFs膜性能明显提高,其对PVA的增强效果更佳,可以作为高强度、高透明包装材料使用。

To study the feasibility of preparing functional packaging composite from disused filter paper pulp by mechanical means. Mechanical methods including grinding and homogenization were used to separate 2 types of cellulose nanofibers（CNFs） in different sizes from the untreated and acetic acid-pretreated disused filter paper pulp. The water suspension of well-dispersed CNFs was filtered and then oven-dried to prepare films. Two types of CNFs-reinforced Polyvinyl Alcohol（PVA） composites were prepared by impregnation method, and their mechanical properties and transmittance were tested. The FE-SEM images showed that the diameter of CNFs from untreated pulp was distributed in the range of 300~500 nm, while that from acetic acid-pretreated pulp was significantly reduced to 80~100 nm.Compared with PVA sheet, the tensile strength（90.45 MPa） and the light transmittance（81.3%） of the acetic acid-pretreated CNFs/PVA composites were respectively raised by 201% and decreased by 10.3%. The result revealed that the addition of CNFs enhanced the mechanical properties of PVA, and that acetic acid-pretreated CNFs had better effects, which could be used as high-strength and highly transparent packaging materials.