ch 2 u2014 ch ch 2 3 and methylene bis acrylamide bis aldrich initiators tertiary butyl peroxy pivalate lupersol u00ae 11 and tertiary amyl peroxy pivalate lupersol u00ae 554 lucidol solvent deionized water non solvent heptane aldrich the optimized reaction cycling time is very short 1 5 hours at 60 u00b0 c and 4 hours at 85 u00b0 c the process includes the steps of 1 clean dry and tare a 1 liter glass resin reaction flask 2 install the reactor with agitator heating mantle condenser thermocouple septum for initiator addition and nitrogen purging 3 add part of water solvent all vp monomer all dmapma monomer all the bis crosslinker and all the lupersol u00ae 11 initiator into the reactor the vp dmapma ratio will vary depending on the kind of hydrogel to be made a preferred initial concentration of vp and dmapma in the system is 20 by weight the preferred weight ratio of crosslinker to vp and dmapma is 0 20 the preferred weight ratio of lupersol u00ae 11 to vp and dmapma is 1 10 4 at room temperature start a purge with nitrogen until the reaction is complete 5 raise the temperature to 60 u00b0 c and maintain for 1 5 hours 6 during the 60 u00b0 c period when gelation occurs and the system is too viscous to agitate add water to dilute the system from 20 to 10 solids 7 raise the temperature to 85 u00b0 c and maintain for 4 hours to reduce the residual monomer level 8 when reaching 85 u00b0 c directly inject lupersol u00ae 554 hourly through the syringe and rubber septum on the top of reactor into the reaction mixture four 4 additions of lupersol u00ae 554 as.