Synthesis and property study of cellulose methyl carbonate in DMSO/DBU/CO2 system via in situ organocatalysis

Cellulose is the most abundant biorenewable resource on the earth, and is also characterized by its low price, easy derivatization and good biodegradable property. It is believed that derivatization is an important strategy to extend its applications. Cellulose carbonate is one of the most important classes of cellulose derivatives, as they have good potential in the field of green packaging film materials, thermoplastics, solid electrolyte, and so on. In this study, cellulose methyl carbonate has been synthesized successfully after the dissolution of cellulose in the novel 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)/DMSO/CO2 system followed by the addition of dimethyl carbonate via the in-situ organocatalysis by DBU. The structure and thermal properties of the as prepared cellulose methyl carbonate were systematically characterized by NMR, FTIR, TGA and DSC. The results show that cellulose methyl carbonate with a DS of 1.09 was achieved after 12 h at 60 °C with molar ratio of dimethyl carbonate/AGU at 8:1. The DSC/TGA results show that the cellulose methyl carbonate with DS=1.09 has a Tg of 62.9 °C and starts thermal degradation at 305.5 °C.