Fibers pre-treatments with sodium silicate affect the properties of suspensions, films, and quality index of cellulose micro/nanofibrils
Adriano Reis Prazeres Mascarenhas, Mário Vanoli Scatolino, Matheus Cordazzo Dias, Maria Alice Martins, Rafael Rodolfo de Melo, Renato Augusto Pereira Damásio, Maressa Carvalho Mendonça, Gustavo Henrique Denzin Tonoli
Abstract
Abstract The characteristics of cellulose micro/nanofibrils (MFC/CNF) can be improved with pre-treatments of the original fibers. The present work is proposed to study pre-treatment with sodium silicate (Na 2 SiO 3 ) on bleached fibers of Eucalyptus sp. (EUC) and Pinus sp. (PIN) and its effects on the quality index of MFC/CNF. Particle homogeneity, turbidity, and microstructure of the suspensions were evaluated. Similarly, the physical-mechanical, and barrier properties of the films were studied. With the results obtained for suspensions and films, the quality index (QI) was MFC/CNF calculated. The smallest particle dimension was observed for MFC/CNF of Pinus sp. with 10 % of Na 2 SiO 3 , as well as the lowest turbidity (∼350 NTU) was obtained for MFC/CNF of Pinus sp . with 5 % of Na 2 SiO 3 . The pre-treatments reduced the transparency of the films by ∼25 % for EUC and ∼20 % for PIN. The films presented a suitable barrier to UVC radiation, water vapor, and oil. The tensile strength of EUC and PIN films was increased by 20 % using 10 % of Na 2 SiO 3 . The same concentration of Na 2 SiO 3 provided QI 70 for EUC MFC/CNF. The Na 2 SiO 3 was efficient to obtain the MFC/CNF with interesting properties and suitable to generate films with parameters required for packaging.