摘要
使用造纸方法快速成功的制备了纳米纤维素,纳米二氧化硅复合材料,对并材料的力学性能,热性能和吸湿性能进行了分析。研究结果表明:随着纳米二氧化硅的添加量逐步提高,纳米复合材料的理论密度逐渐下降,材料的拉伸性能和模量值都有大幅度的下降。材料热解的初始降解温度和热解活化能随着纳米二氧化硅质量分数的增多提升,当纳米二氧化硅质量分数为20%时,材料初始热解温度为280℃。纳米复合材料的含水率随着吸湿时间的延长而增加,且随着纳米二氧化硅添加量的增多,材料的最终含水率不断提高,当纳米二氧化硅质量分数为20%时,纳米复合材料的最终含水率约26%,纳米复合材料的表面接触角值仅为40.4°。该研究结果可为制备了纳米纤维素/纳米二氧化硅复合材料提供参考。
In this study, cellulose nano-fibril （CNF）/nano-silicon dioxide composites were prepared by mimicking the fast paper-making method. Mechanical property, thermal degradation and moisture adsorption of the composites were studied. The results revealed that tensile strength and modulus decreased as the loading of nano-silicon dioxide increased. The measured density value of CNF was 1 305.04 kg/cm^3 while the density of CNF with 20% nano-silicon was only 1 132.9 kg/cm^3. Tensile strength of CNF was 120.98 MPa and Modulus was 6.41 GPa. As the loading of nano-silicon dioxide increased, the tensile strength and modulus decreased sharply. When the content of nano-silicon dioxide reached 20%, the tensile of nano-composite was 49.41 MPa and the modulus was 2.96 GPa. The thermal stability of nano-composite was improved after adding nano-silicon dioxide. The onset cellulose decomposition temperature was around 270 C and weight loss in this period was around 4%. Although the onset decomposition temperature of nanocomposites did not increase, the lower weight loss indicated less initial decompositions in this stage. In addition, as the content of silica became higher, the char residue increased. The amount of dry plain CNF was 23%, noticeably smaller than that of corresponding CNF/nano-silicon dioxide samples which ranged from 30% and 65%. Degradation models including the Kissinger, modified Coats-Redfern and Flyrm-Wall-Ozawa （F-W-O） methods were utilized to calculate the activation energy. The Kissinger method led to an apparent activation energy ranging from 150 to 225 for all films. NFC with inorganic silica normally showed a higher activation energy than the control, high clay content also resulted in high activation energy. Results from the modified Coats-Redfern and F-W-O methods were similar （activation energy ranged from 180 to 220） to the observations. Nano-silicon dioxide provides barrier to the oxygen which leads to an improvement in flame retardant property. Limiting oxygen index of the tested CNF was 2
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2015年第7期299-303,共5页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家林业公益行业科研专项"木质纤维化学材料及功能化技术"(201104004)
关键词
纳米复合材料
纳米纤维素
力学性质
纳米二氧化硅
热性能
吸湿性
nanocomposites
nano-fibers
mechanical properties
nano-silicon dioxide
thermal properties
moisture absorption
