Cassava starch was used as the main chain in the copolymerization of
a superabsorbent polymer composite (SAPC) based on acrylic acid and
bentonite. The SAPC was synthesized through graft polymerization using nanosized bentonite as reinforcement. The variables in this experiment were:
bentonite concentration, acrylic acid to starch weight ratio, concentration of
initiator, and cross linker. The product was characterized using FTIR, SEM and
TGA-DSC. The results show that the polymerization reactions involved
processes of incorporating starch chains as polymer backbone and grafting
acrylic acid monomers onto it. The use of cassava starch in the polymerisation
produced a very short reaction time (10-15 minutes), which led to SAPC
production with higher efficiency and lower cost. Bentonite interacts with
monomers via hydrogen and weak bonding, thus improving the thermal
properties of the product. The maximum absorbance capacity obtained was at an
acrylic acid to starch weight ratio of 5 and a concentration of initiator, cross
linker and bentonite of 0.5, 0.05 and 2 weight percent, respectively. The product
is suitable for agricultural and medical applications as well as common
superabsorbent polymer applications.