2.2. Synthesis of acrylic acid-co-acrylamide based IPN [Gt-cl-poly(AAip-
AAm)]
Acrylic acid was grafted onto Gum tragacanth in an aquous
medium using lipase as an initiator and glutaraldehyde as a cross-
linker. To get the graft copolymer Gum tragacanth (1 g) was taken in
a reaction
flask containing known amount of water and was stirred
thoroughly. A known concentration of lipase was added followed
by drop by drop addition of acrylic acid and glutaraldehyde into the
reaction mixture. Stirring was continued until the homogenous
mixture was obtained. Graft copolymer was extracted using
slightly heated distilled water. Finally, hydrogel obtained was dried
in hot air oven at 40 C. The synthesized product was then taken in
a
flask having known amount of distilled water followed by
addition of acrylamide and lipase and kept for 24 h. After 24 h
glutaraldehyde was added with constant stirring and kept in oven
at 40 C for 48 h. It was washed with slightly heated distilled water
and kept for drying in hot air oven. Percentage grafting (Pg) of
synthesized interpenetrating polymer network was calculated
using the following equation