Frontal polymerization – a rapid route for synthesizing superabsorbent polymers based on jackfruit seed starch grafted acrylic monomers

Abstract This study focuses on the synthesis of superabsorbent polymers (SAPs) from jackfruit seed starch and acrylic monomers using the frontal polymerization (FP) method. Acrylic acid (AA) and acrylamide (AM) were grafted onto jackfruit seed starch with varying initiator contents (0.5, 0.75, 1, and 1.5 wt%) in the presence of MBA as a cross-linker (0.1 wt% relative to AA) to produce SAPs. The effect of external heat source temperature was also investigated. Using an external heat source at 1200 °C and a PPS initiator content of 1% resulted in SAPs JFSS-g-AA and JFSS-g-AM with water absorption capacities (WAC) of 415 g g −1 and 298 g g −1 , respectively. In comparison, the conventional method yielded WACs of 364 g g −1 and 273 g g −1 for the same polymers. The synthesized polymers were characterized using FTIR, SEM, TGA, and XRD. The grafted polymers exhibited superior properties, including shorter reaction times and lower costs than conventional methods, as FP requires only an initial energy input to initiate polymerization, with no further energy needed. FP samples achieved reaction times of 19–21 min, significantly shorter than those of conventional samples (49 and 46 min, respectively). An increase in the external heat source temperature raised the front temperature, with a recorded peak of 126 °C. The frontal velocity was proportional to the initiator content, influencing the propagation of the reaction front. Compared to conventional polymerization, FP produced polymers with higher absorption capacity. These findings suggest that FP is a cost-effective and time-efficient alternative for synthesizing graft polymers from acrylic monomers and starch.