Green Semi-IPN Hydrogels by Direct Utilization of Crude Wood Hydrolysates

Abstract

Crude and unmodified acetylated galactoglucomannan containing wood hydrolysate (WH) was directly incorporated into a semi-interpenetrating network (semi-IPN) composed of up to 60% renewable polymers. Semi-IPNs were produced by a facile and green synthetic pathway through cross-linking modified carboxymethylcellulose in the presence of at least 30%(w/w) WH, via free radical copolymerization with acrylic acid and <i>N</i>,<i>N</i>′-methylenebis­(acrylamide). FTIR verified the presence of WH interlaced with CMC in the semi-IPN, and the highly porous microscopic structure of the networks was confirmed by SEM. The gelation process of these networks was monitored in situ, and their individual “gel point” (the <i>G</i>′-<i>G</i>″ crossover) was determined by in situ rheological measurements. Semi-IPN hydrogels with various swelling ratios (<i>Q</i> = 20–225) were obtained within 2.8–20 min of a cross-linking reaction