*2.3. Synthesis of Gum Tragacanth-cl-N,N-dimethylacrylamide (GT-cl-poly(DMA)) Hydrogel*

Microwave-assisted copolymerization method was used in the synthesis of gum tragacanth-cl-*N,N*-dimethylacrylamide hydrogel [5]. In a typical reaction, 0.5 g of gum tragacanth (GT) (in 11 mL of deionized water) was taken in 50 mL beaker, stirred until GT was uniformly mixed with distilled water. After this, KPS (10 <sup>×</sup> 10−<sup>1</sup> mol L−1) and NMBA (5.8 <sup>×</sup> 10−<sup>1</sup> mol L−1) were added into the GT solution. Magnetic stirring was continued to get a homogenous mixture and then 4.4 <sup>×</sup> <sup>10</sup>−<sup>1</sup> mol L−<sup>1</sup> of DMA was added in this mixture. The solution mixture was placed under microwave radiations for 90 s to generate active radicals needed for the initiation of the polymerization reaction. The prepared gel was washed using acetone and dried inside the preheated (50 ◦C) hot air oven for 24 h.
