Synthesis of organic-inorganic polymer hybrids using cellulose nanofibers and water glass

Abstract

An aqueous solution of mechanically disintegrated cellulose nanofiber (CNF) was stirred at room temperature for 1 h in the presence of water glass (WG) at a CNF/SiO2 ratio of 11.1/88.9. After stirring, a relatively transparent polymer hybrid was obtained by standing at 40°C for 10 days and drying under reduced pressure at 60°C for 48 h. The weight loss temperature (Td10) of the obtained polymer hybrid increased by 10% compared with that of the raw CNF, indicating that the polymer hybridization improved heat resistance. On the other hand, an aqueous solution of chemically disintegrated cellulose nanofiber (TOCNF) prepared by 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) oxidation in the presence of WG at a TOCNF/SiO2 ratio of 90.0/10.0 generated a relatively transparent polymer hybrid by stirring the solution at room temperature for 1 h, standing at 40°C for 10 days, and drying under reduced pressure at 60°C for 48 h. When polymer hybridization was performed using TOCNF, increasing the amount of WG used resulted in an increase in Td10, indicating a tendency for the improved heat resistance by the polymer hybridization.