Research On Temperature And PH Dual Responsive Amphiphilic Copolymer Based On N-vinylcaprolactam

Temperature and pH dually responsive polymer which not only can respond to the change of temperature,but also can respond to the change of pH for the volume phase transition.Temperature and pH dually responsive polymers have significant applications in the field of controlled release of drug,gene transfection and catalsis.Poly(N-vinylcaprolactam)(PNVCL)is a biocompatibility,nonionic,good solubility in water and thermal responsiveness,whose lower critical solution temperature(LCST)is in the range of physiological temperature.Diethyl allyl is a pharmaceutical raw materials which have been commercialized.Hydrolysis of the polymer can generates carboxyl group.At present,diethyl allyl as apolymer monomer have not been reported.Study the copolymers of N-vinylcaprolactam and diethyl allyl have the expect to get the temperature and pH dually responsive polymer,and may develop a new kind of pH responsive polymer monomer.In this thesis,Poly(Diethyl allyl)-co-poly(N-vinylcaprolactam)have been synthesized with three different chain segment ratio(A1?A2?A3).And hydrolysis of these copolymers.Synthesis three pH and temperature dually responsiveness of poly(allylmalonic acid)-co-poly(N-vinycaprolactam)(B1?B2?B3).The structure of this six new copolymers have been characterized by ~1H NMR?IR and GPC-MALLS.The results showed that the thermoresponsive properties of this six copolymers.The copolymer with carboxy(B1?B2?B3),their LCST were affected by pH.Fluorescent spectroscopy and TEM studies revealed their six copolymer can self-assemble into the micelles,the higher of the content of Diethyl allyl and concentration was,the lowers their LCST values were.The higher of the content of NVCL,the higher of the low critical micelle concentration.The drug loading capacity of micelles of the copolymers is very good,and can prolong the release time of drugs.have sustained-release effect for podofilox.