Reinforcing potential of wood pulp-derived microfibres in a PVA matrix

Abstract

In this study, the reinforcing potential of cellulose “microfibres” obtained from bleached softwood kraft pulp was demonstrated in a matrix of polyvinyl alcohol (PVA). Microfibres are defined as fibres of cellulose of 0.1–1 μm in diameter, with a corresponding minimum length of 5–50 μm. Films cast with these microfibres in PVA showed a doubling of tensile strength and a 2.5-fold increase in stiffness with 5% microfibre loading. The theoretical stiffness of a microfibre was calculated as 69 GPa. The study also demonstrated that the strength of the composite was greater at 5% microfibre loading compared to 10% loading. Comparative studies with microcrystalline cellulose showed that the minimum aspect ratio of the reinforcing agent is more criticalthan its crystallinity in providing reinforcement in the composite.

Dimension change in microfibrillated cellulose from different cellulose sources by wet disk milling and its effect on the properties of PVA nanocomposite

“…These tensile properties are comparable with those from previous reports (Cheng et al 2009;Wang and Sain 2007;Chakraborty et al 2006). For example, Chakraborty et al (2006) reported that tensile strength and elastic modulus of the PVA nanocomposite reinforced by 5 % MFC were 102 MPa and 5.2 GPa, respectively. Figure 6 shows SEM images of the cryo-fractured surface of the nanocomposite reinforced with 1 % MFC addition.…”

Neutral Sulfite Treatment of Lignocellulosic Pulps

“…In addition, the extremely low level of the viscosity and low DP of cellulose indicated that the harsh sulfite treatment produced mainly microcrystalline cellulose. In the literature a DP of 225 has been reported for microcrystalline cellulose (Chakraborty et al 2006); this value is very close to the DP of the sulfite-treated samples ( Table 1).…”

“…Microcrystalline cellulose (MCC) itself can be used as a reinforcement material in composites (Chakraborty et al 2006). In addition, gels based on MCC have applications in several fields, such as medicine, the food industry, cosmetics, agriculture, and the paper industry (Laka and Chernyavskaya 2009).…”

Biodegradation behaviors and water adsorption of poly(vinyl alcohol)/starch/carboxymethyl cellulose/clay nanocomposites

“…Parallel with increase of awareness on environment, recently, more environmentally friendly and biodegradable materials have called a lot of attention. For fully biodegradable composites, considerable researches have been done on synthetic polymers having backbones like polylactic acid [6], polyvinyl alcohol (PVA) [7,8], and polycaprolactone [9] as potential matrix. Among synthetic water-soluble polymers throughout the world, PVA is the largest which has broad applications [10].…”