Application of polymeric multilayers of starch onto wood fibres to enhance strength properties of paper

Abstract

SUMMARY:Polyelectrolyte multilayers of cationic and anionic starch have been used to enhance the strength properties of paper. All starches used in this investigation had a degree of substitution around 0.065. Optical reflectometry showed that a combination of cationic and anionic starch could form polyelectrolyte multilayers onto silicon oxide surfaces. The same combination of starches was then applied to unbeaten, bleached softwood kraft fibres to form three layers, i.e. a cationic-/anionic/cationic starch combination. The results showed a significant increase in the paper strength properties in terms of tensile index, strain at break, and Scott Bond. The adsorbed amount of starch in the sheets, determined using an enzymatic method, was found to increase with each successive starch treatment. The increased paper strength was not only due to the increase in adsorbed amount of starch; rather, the chemical composition of the starch was also important. Cationic starch with high amylose content had a more positive effect on the paper strength properties. Furthermore, it was observed that anionic starch, despite being adsorbed in large amounts, did not contribute to the increase in tensile strength or strain at break to the same extent as did cationic starch. However, the out-ofplane properties, measured as Scott Bond properties, increased with the adsorbed amount, regardless of the chemical composition of the starch used in the outermost layer.

β-Cyclodextrin Grafted Cellulose and Cationic Starch for Antibacterial Paper Products: A Comparative Study

“…When the adding amount of β-CD-CSCipHCl was 2.5%, the tensile and tear index were increased 36.8% and 9.0%, respectively. It is believed that β-CD-CS-CipHCl adsorbs to cellulosic fibers during wet end processing, thereby enhancing bonding strength between the fibers during the process of sheet forming (Eriksson et al 2005;Hubbe 2007). It is well known that the adsorption of CS on fibers will reach a saturation condition and any further increase of the adsorption amount beyond the saturation point is impossible.…”

Wood production, wood technology, and biotechnological impacts

“…Most starches consist of about 70% amylopectin and 30% of hot water soluble amylose. However, there are source-dependent differences and these will influence the properties of the starch as adhesive , Eriksson et al 2005. In spite of this, a common problem with starch-based adhesives is a reduced water-resistance of the products (Basta et al 2005, Dix 2006see below).…”

The use of polyelectrolyte multilayers of cationic starch and CMC to enhance strength properties of papers formed from mixtures of unbleached chemical pulp and CTMP. Part II Influence of addition strategy, fibre treatment and fibre type

“…The first practical application aimed at adsorbing high amounts of cationic PAE (polyamideamine epichlorohydrine), a common wet strength additive, to improve wet strength in tissue paper by combining the PAE treatment with a carboxymethylcellulose CMC treatment (Sandberg and Andreasson 2000). Later work along these lines has also shown that the structure of the multilayers (Eriksson et al, 2005a, Notley et al, 2005 as well as the chemical structure of the used chemicals (Eriksson et al 2005b) have a large influence on the strength-enhancing properties. PEMs of cationic amylose and anionic potato starch were also shown to be much more efficient than conventional PEMs of conventional cationic and anionic potato starch (Eriksson et al 2005b).…”

“…Later work along these lines has also shown that the structure of the multilayers (Eriksson et al, 2005a, Notley et al, 2005 as well as the chemical structure of the used chemicals (Eriksson et al 2005b) have a large influence on the strength-enhancing properties. PEMs of cationic amylose and anionic potato starch were also shown to be much more efficient than conventional PEMs of conventional cationic and anionic potato starch (Eriksson et al 2005b). In Notley et al (2005) it was furthermore shown that a high mobility of the polyelectrolyte multilayer was important to create a strong fibre/fibre joint.…”