Effect of nanocellulose isolation techniques on （nanocellulose隔离技术的影响）.pdfVIP

eXPRESS Polymer Letters Vol.6, No.10 (2012) 794–804 Available online at DOI: 10.3144/expresspolymlett.2012.85 Effect of nanocellulose isolation techniques on the formation of reinforced poly(vinyl alcohol) nanocomposite films 1 1* 2 1 Y. M. Zhou , S. Y. Fu , L. M. Zheng , H. Y. Zhan 1State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Science, South China University of Technology, Guangzhou, 510640 Guangdong, China 2School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640 Guangdong, China Received 19 February 2012; accepted in revised form 1 May 2012 Abstract. Three techniques including acid hydrolysis (AH), 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-medi- ated oxidation (TMO) and ultrasonication (US) were introduced to isolate nanocellulose from microcrystalline cellulose, in order to reinforce poly(vinyl alcohol) (PVA) films. Important differences were noticed in fiber quality of nanocellulose and film properties of PVA nanocomposite films. The TMO treatment was more efficient in nanocellulose isolation with higher aspect ratio, surface charge (–47 mV) and yields (37%). While AH treatment resulted in higher crystallinity index (88.1%) and better size dispersion. The fracture surface, thermal behavior and mechanical properties of the PVA nanocomposite films were investigated by means of scanning electron microscopy (SEM), differential scanning calorimetry (DSC), ther- mogravimetric analysis (TGA) and tensile testing. The results showed that both the TMO-derived and AH-derived nanocel- lulose could be dispersed homogeneously in the PVA matrices. AH/PVA films had higher elongation at break (51.59% at 6 wt% nanocellulose loading) as compared with TMO/PVA, while TMO/PVA films shown superior tensile modulus and strength with increments of 21.5% and 10.2% at 6wt% nanocellulose loading. The