Preparation and characterization of poly(vinyl alcohol) nanocomposites made from cellulose nanofibers

Abstract

A method using a combination of ball milling, acid hydrolysis, and ultrasound was developed to obtain a high yield of cellulose nanofibers from flax fibers and microcrystalline cellulose (MCC). Poly(vinyl alcohol) (PVA) nanocomposites were prepared with these additives by a solution-casting technique. The cellulose nanofibers and nanocomposite films that were produced were characterized with Fourier transform infrared spectrometry, Xray diffraction, thermogravimetric analysis, scanning electron microscopy, and transmission electron microscopy. Nanofibers derived from MCC were on average approximately 8 nm in diameter and 111 nm in length. The diameter of the cellulose nanofibers produced from flax fibers was approximately 9 nm, and the length was 141 nm. A significant enhancement of the thermal and mechanical properties was achieved with a small addition of cellulose nanofibers to the polymer matrix. Interestingly, the flax nanofibers had the same reinforcing effects as MCC nanofibers in the matrix. Dynamic mechanical analysis results indicated that the use of cellulose nanofibers (acid hydrolysis) induced a mechanical percolation phenomenon leading to outstanding and unusual mechanical properties through the formation of a rigid filler network in the PVA matrix. X-ray diffraction showed that there was no significant change in the crystallinity of the PVA matrix with the incorporation of cellulose nanofibers.

Preparation and Characterization of Polyvinyl Alcohol-Based Composite Reinforced with Nanocellulose and Nanosilica

“…However, the tensile strength exhibited very little tendency to increase when the incorporation of nanocellulose exceeded 5 wt%. The same observation has been reported by previous researchers (Bhatnagar and Sain 2005;Sturcova et al 2005;Qua et al 2009;Ibrahim et al 2010). This behavior could be explained by the fact that small amounts of nanofillers allowed the creation of strong hydrogen bonds between nanocellulose and PVA, which contributed to good dispersion of nanofillers in the PVA matrix and resulted in superior load transfer from the matrix to the nanocellulose and nanosilica reinforcements.…”

Properties of Polymer Composites with Cellulose Microfibrils

“…Figure shows that the second degradation region is located between 220 and 300 0 C and is due to the pyrolysis of cellulose fibers and to the degradation of PVA films, the weight loss being around 70% for all the samples. As reported by Qua et al (2009), the second stage of degradation mainly involves dehydration reactions and the formation of volatile products. The third stage weight loss occurrs above 400 0 C and consists of decomposition of carbonaceous matter (Lee et al, 2009b).…”

“…In the obtained PVA thermograms (Fig. 10) three main weight loss regions can be observed (Lee et al, 2009b;Qua et al, 2009). All the samples show an initial weight loss in the region 75 -150 0 C caused by the evaporation of water.…”

Preparation and characterization of nanofibrillated Cellulose/Poly (Vinyl Alcohol) composite films

“…Among the renewable source-based biodegradable plastics, poly (vinyl alcohol) (PVA) is one of the most promising materials since it is thermoplastic, biodegradable, biocompatible and has high-strength, high-modulus and good processability (Lu et al 2008, Roohani et al 2008. It is water soluble, semi-crystalline with the excellent chemical resistance, and has no toxic action on the human body (Qua et al 2009, Kaboorani et al 2012. PVA is widely used in adhesives, paints, sealants, coatings, textiles, plastics, tissue scaffolding, filtration materials, membranes, optics, enzyme immobilization, drug release, etc (Roohani et al 2008, Qua et al 2009, Kaboorani et al 2012.…”

“…It is water soluble, semi-crystalline with the excellent chemical resistance, and has no toxic action on the human body (Qua et al 2009, Kaboorani et al 2012. PVA is widely used in adhesives, paints, sealants, coatings, textiles, plastics, tissue scaffolding, filtration materials, membranes, optics, enzyme immobilization, drug release, etc (Roohani et al 2008, Qua et al 2009, Kaboorani et al 2012.…”