Graft copolymerization of carboxymethylcellulose with solketal acrylate

The objective of this work is to synthesize new materials based on cellulose fiber. In this study, we presented the synthesis of a new biomaterial by conducting graft polymerization of 2,2-dimethyl-1,3-dioxolan-4-yl methyl acrylate (DMDMA solketal acrylate) onto carboxymethylcellulose (CMC), using KPS as an initiator. We conducted several experiments to determine the optimal conditions for preparing this biopolymer, varying the reaction time and the ratio between the initiator and the monomer. The results revealed that the highest grafting yield, 52%, was obtained after 72 min at 65 °C, with 6.26 mmol of KPS/eq OH and 4.43 moles of DMDMA/eq OH, using THF as a solvent. FTIR spectroscopy confirmed the grafting of monomers onto the CMC. Thermogravimetry showed that the degradation of the grafted CMC occurs in two stages, unlike the degradation of the CMC, which occurs in a single stage, confirming the modification of the starting product. SEM images clearly show the morphological difference between the CMC and the grafted CMC. The BET analysis reveals moderate adsorption at low pressure, followed by a marked increase at high pressure, indicating the presence of mesopores. The hysteresis between adsorption and desorption also suggests closed pore structures. The pore size distribution shows a predominance of pores between 30 and 100 Å, providing an optimal specific surface area for small molecule adsorption and catalytic reactions. This mesoporous profile is suitable for adsorption and catalysis applications. To our knowledge, our study represents the first use of the synthesized monomer, DMDMA solketal acrylate, for grafting onto the structure of CMC, highlighting the originality of our research.