A biobased binder of carboxymethyl cellulose, citric acid, chitosan and wheat gluten for nonwoven and paper.

Wennman M, Pinon AC, Svagan AJ, Hellberg M, Hedenqvist MS

Carbohydr Polym 323 (-) 121430 [2024-01-01; online 2023-09-23]

The amount of disposable nonwovens used today for different purposes have an impact on the plastic waste streams which is built up from several single-use products. A particular problem comes from nonwoven products with "hidden" plastic (such as cellulose mixed with synthetic fibers and/or plastic binders) where the consumers cannot see or expect plastic. We have here developed a sustainable binder based on natural components; wheat gluten (WG) and a polyelectrolyte complex (PEC) made from chitosan, carboxymethyl cellulose and citric acid which can be used with cellulosic fibers, creating a fully biobased nonwoven product. The binder formed a stable dispersion that improved the mechanical properties of a model nonwoven. With WG added, both the dry and the wet strength of the impregnated nonwoven increased. In dry-state, PEC increased the tensile index with >30 % (from 22.5 to 30 Nm/g), and with WG, with 60 % (to 36 Nm/g). The corresponding increase in the wet strength was 250 % (from 8 to 28 Nm/g) and 300 % (to 32 Nm/g). The increased strength was explained as an enrichment of covalent bonds (ester and amide bonds) established during curing at 170 °C, confirmed by DNP NMR and infrared spectroscopy.

Swedish NMR Centre (SNC) [Collaborative]

PubMed 37940257

DOI 10.1016/j.carbpol.2023.121430

Crossref 10.1016/j.carbpol.2023.121430

pii: S0144-8617(23)00895-0