Extrusion and characterization of functionalized cellulose whiskers reinforced polyethylene nanocomposites
Extrusion and characterization of functionalized cellulose whiskers reinforced polyethylene nanocomposites
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DOI：
10.1016/j.polymer.2009.07.038
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发表时间：
2009-09-10
期刊：
影响因子：
4.6
通讯作者：
Dufresne, Alain
中科院分区：
文献类型：
--
作者：
de Menezes, Aparecido Junior;Siqueira, Gilberto;Dufresne, Alain
通过酯化反应，接枝不同长度脂肪链的有机酸氯化物，对苎麻纤维素晶须表面进行了化学改性。通过FTIR、X-射线光电子能谱、元素分析和接触角测量对化学改性的发生进行了评价。链接枝并没有改变粒子的结晶度，但研究表明，当使用C18时，共价接枝的链能够在纤维素表面结晶。将未改性纳米颗粒和功能化纳米颗粒与低密度聚乙烯共挤，制备纳米复合材料。随后得到的纳米复合材料的均匀度随着接枝链长的增加而增加。用差示扫描量热仪(DSC)、动态力学分析(DMA)和拉伸试验研究了制备的纳米复合材料的热机械性能。当足够长的链被接枝到纳米颗粒的表面时，可以观察到断裂伸长率的显著改善。这归因于纳米粒子在LDPE基质中的分散程度提高。(C)2009爱思唯尔有限公司。保留所有权利。
The surface of ramie cellulose whiskers has been chemically modified by grafting organic acid chlorides presenting different lengths of the aliphatic chain by an esterification reaction. The occurrence of the chemical modification was evaluated by FTIR and X-ray photoelectron spectroscopies, elemental analysis and contact angle measurements. The crystallinity of the particles was not altered by the chain grafting, but it was shown that covalently grafted chains were able to crystallize at the cellulose surface when using C18. Both unmodified and functionalized nanoparticles were extruded with low density polyethylene to prepare nanocomposite materials. The homogeneity of the ensuing nanocomposites was found to increase with the length of the grafted chains. The thermomechanical properties of processed nanocomposites were studied by differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA) and tensile tests. A significant improvement in terms of elongation at break was observed when sufficiently long chains were grafted on the surface of the nanoparticles. It was ascribed to improved dispersion of the nanoparticles within the LDPE matrix. (C) 2009 Elsevier Ltd. All rights reserved.