Paper strengthening by polyaminoalkylalkoxysilane copolymer networks applied by spray or immersion: a model study

Abstract

Two di-alkoxysilanes, with (AMDES, aminopropylmethyldiethoxysilane) or without (DMDES, dimethyldiethoxysilane) an amine function, and a trialkoxy aminosilane (APTES, aminopropyltriethoxysilane) as well as their mixtures were introduced in paper as fiber strengthening agents. The polymerization and copolymerization of these polysiloxanes in the paper were investigated. In all the cases where APTES was present, the formation of networks was established by measuring the soluble fraction amount extracted from the treated papers. A slight decrease of the opacity of the paper sheets when AMDES was part of the treatment was noted. The presence of APTES reduced this opacity loss. The study of the physicochemical properties of the treated paper (mechanical strength and alkalinity) demonstrated that, besides the required deacidification feature, the different treatments allowed an efficient strengthening of the cellulose fibers to various extents. Contact angle measurements indicated a decrease of the hydrophilic character of papers treated with the mixture APTES/AMDES and the occurrence of a hydrophobic character of the papers treated with APTES alone. These results were consistently obtained for both spray and immersion treatment processes.

Polysaccharide stabilized nanoparticles for deacidification and strengthening of paper

“…16,17 Recently this solvent was used together with soluble amine-bearing siloxanes for the deacidi-cation and strengthening of paper. 3,11,12 Although, the above mentioned deacidication methods are versatile in one or the other way, a suitable approach to overcome some drawbacks is to employ substances that are fully compatible with the treated materials.…”

Nonaqueous solution deacidification treatments to prolong the storage life of acidic books: A review of mechanistic and process aspects

“…the same solvent employed in the Batelle mass deacidification system. The deacidification effect, which can be attributed to the amino functionality within the polymerized silane material, was confirmed by increases in the alkaline reserve content of treated paper (Piovesan et al 2014). Dupont et al (2010) suggested that the mechanism of strengthening involves hydrogen bonding, consistent with the development of strength in ordinary paper.…”

“…Aminopropylmethyl diethoxysilane Ipert et al 2006;Dupont et al 2010;Souguir et al 2011Souguir et al , 2012Piovesan et al 2014Piovesan et al , 2017 To reinforce the point that relatively low surface tension liquids have been used, whereas pure water has a surface tension of about 72 mNm -1 at room temperature, the other liquids listed in Table 3 generally have much lower values (e.g. HMDS 15.6 mNm -1 ; heptafluoropentane 15.1 mNm -1 ).…”

“…A process based on polyaminoalkylalkoxysilanes has been developed to provide both deacidification and strengthening simultaneously (Ipert et al 2006;Dupont et al 2010;Souguir et al 2011Souguir et al , 2012Piovesan et al 2014Piovesan et al , 2017. The treatment was found to increase both the tensile strength and the folding endurance, including when paper sheets were evaluated after aging.…”

“…Dupont et al (2010) suggested that the mechanism of strengthening involves hydrogen bonding, consistent with the development of strength in ordinary paper. The greatest strength improvements were observed when paper was treated to form a copolymer of two di-alkoxyiloxanes, one with and one without an amine functionality (Piovesan et al 2014).…”