Properties and Hydrophobization of Nonwoven-Woven All-Cellulose Composites
Eija-Katriina Uusi-Tarkka,
Eemeli Eronen,
Afshan Begum,
Janne Jänis,
Nawar Kadi,
Pooria Khalili,
Mikael Skrifvars,
Henrik Heräjärvi,
Antti Haapala
Affiliations
Eija-Katriina Uusi-Tarkka
Department of Chemistry, Faculty of Science, Forestry and Technology, University of Eastern Finland, FI-80101 Joensuu, Finland
Eemeli Eronen
Department of Chemistry, Faculty of Science, Forestry and Technology, University of Eastern Finland, FI-80101 Joensuu, Finland
Afshan Begum
Department of Chemistry, Faculty of Science, Forestry and Technology, University of Eastern Finland, FI-80101 Joensuu, Finland
Janne Jänis
Department of Chemistry, Faculty of Science, Forestry and Technology, University of Eastern Finland, FI-80101 Joensuu, Finland
Nawar Kadi
Department of Textile Technology, Faculty of Textiles, Engineering and Business, University of Borås, SE-50190 Borås, Sweden
Pooria Khalili
Swedish Centre for Resource Recovery, Faculty of Textiles, Engineering and Business, University of Borås, SE-50190 Borås, Sweden
Mikael Skrifvars
Swedish Centre for Resource Recovery, Faculty of Textiles, Engineering and Business, University of Borås, SE-50190 Borås, Sweden
Henrik Heräjärvi
School of Forest Sciences, Faculty of Science, Forestry and Technology, University of Eastern Finland, FI-80101 Joensuu, Finland
Antti Haapala
Department of Chemistry, Faculty of Science, Forestry and Technology, University of Eastern Finland, FI-80101 Joensuu, Finland; FSCN Research Centre, Mid Sweden University, SE-85170 Sundsvall, Sweden
All-cellulose composites (ACCs) have been fabricated by using a variety of cellulosic sources, versatile technologies, and are sustainable alternatives for traditional composites. In this study, nonwoven-woven ACC laminates were created from wood-based Spinnova short fibers and Lyocell fabrics via partial dissolution and an NaOH-urea solvent system. The less-known wood-based Spinnova fiber is created for the textile industry, but it also has great potential for the composite industry. To identify the mechanical properties of ACCs—which greatly influence the range of material application—tensile, impact, and flexural tests were conducted. The mechanical properties indicated only moderate properties, which are influenced by high porosity and weak fiber bonding. Despite this, valuable information on the nonwoven-woven structured ACCs was obtained. To improve the ACC laminate’s ability to resist moisture, bio-based coatings (e.g., commercially available birch bark betulin and suberin acid mixture) were applied on the surface of ACCs and it successfully improved the wetting resistance. The results of contact angle analyses demonstrated that the highest contact angle of 128° was measured for betulin-coated laminates and the best stable hydrophobicity calculated a minute after the beginning of the experiment were observed at 109° for the uncommercial pressurized hot ethanol (PHE) extract of birch bark.
