Research On Syntheis And Performance Of DMAEMA Series Stimulate-response Hydrogel

Sensitive hydrogel is polymer cross linking network which has a nature ofhydrophilic and undissolve in water, it can response external environment change(suchas pH, ionic strength, temperature, electric field, light field) through its own capacityswelling or contraction, these features impart its can be used in bionic materials design,chemical separation mechanics, drug control release mechanics and chemical valve andso on. In this paper, chemical crosslinking DMAEMA/AA and DMAEMA/AMcopolymerization intelligent hydrogels are prepared by aqua-solution method, weresearch temperature-,pH-,ionic strength-and electric field stimulus responsibility ofthese hydrogels, synthetic process and copolymerization kinetic of DMAEMA/AAco-hydrogel have been studied, otherwise some methods of increasing response rate ofhydrogel have been researched, the main contents and results are as follows:Bis is used as a cross linker, APS and SBS is used as an oxidation-reductioninitiator, hydrogel based on DMAEMA/AA has been synthesized in water solution.ESR ofhydrogel in deionic water is used as main evaluating indicator, the influences ofcross linker concentration, initiator concentration, total monomers mass percent andmass ratio of reactive monomers on swelling performance of hydrogel are investigated.The result shows that hydrogel with good comprehensive performance can be gained,the optimized technological conditions are: cross linker consumption 1.5%,initiatorconsumption 0.4%,total monomer masspercent 30%,DMAEMA:AA=8:2(mass ratio).The result of IR shows that hydrogels through treated which we used to swellingmeasurement are polymer network with complete polymeration.The swelling kineticsof DMAEMA/AA co-hydrogel and its temperature-,pH-,electric field-, ionic strengthstimulus responsibility have been researched systematically, gel block underexeperiment can reach swelling equilibrium approximately through 60h swelling, andits swelling is a non-Fickian process, the gel present notable responsive capacitytowards temperature-, pH-,ionic strength- or electric field stimulus, the critical values of I and pH are 0.2 and 20V individually; under pH＜6 and＞8, ESR of gel increase,and between 6-8, the change of ESR is tiny; the gel block appear continuous changeunder variable temperature between the range of 25-70℃.The same method were used to synthesize DMAEMA/AM co-hydrogel, the effectof synthesize condition were researched, the optimization condition can be gainedthrough orthoglnal experiment. The optimized technological conditions are: crosslinker consumption 1.0%, initiator consumption 0.4%, total monomer mass percent25%, DMAEMA: AM=6:4(mass ratio). The result of IR shows that hydrogels throughtreated which we used to swelling measurement are polymer network with completepolymeration. The swelling kinetics of DMAEMA/AM co-hydrogel and itstemperature-, pH-,electric field-, ionic strength stimulus responsibility have beenresearched systematically, gel block under exeperiment can reach swelling equilibriumapproximately through 50h swelling, and its swelling is a non-Fickian process, the gelpresent notable responsive capacity towards temperature-, pH-,ionic strength- orelectric field stimulus, the critical values of I and pH are 0.3 and 20V individually;under pH＜3 and＞11, ESR of gel increase, and between 3-11, the change of ESR istiny; the gel block appear continuous change under variable temperature between therange of 25-70℃.Some methods of increasing response rate of hydrogels have been researched,since pore structure be introduced in hydrogels synthesized by each of these methods,and the pore structure is favorable to water molecule passage, the hydrogels have fastertemperature-and pH-responsibility, otherwise hydrogels synthesized by these methodshave different swelling ratio in some degree.