Study On Synthesis And Properties Of Intelligent Polymer And Hydrogel Based On Phenylboronic Acid Groups

In this thesis, three different kinds of polymers, linear poly (3-acrylamidophenylboronic acid-co-acryamide)(P(AAPBA-co-AAm)), poly(3-acrylamidophenylboronic acid-co-2-(dimethylamino)ethyl methacry-late)(P(AAPBA-co-DMAEMA)) hydrogel and poly(3-acrylamidophenylboronic ac-id-co-2-(dimethylamino)ethyl methacry-late)/(β-cyclodextrin/epichlorohydrin)(P(AAPBA-co-DMAEMA)/(P-CD/EPI)) semi-IPN hydrogel were prepared by using free radical solution polymerization. The complex between P(AAPBA-co-AAm) and poly(vinyl alcohol)(PVA) in the aqueous solution was investigated by UV/Vis transmittance. The polymers and hydrogels were characterized by FTIR and SEM, and their pH, salt, temperature and glycol sensitivity was investigated by using the classical gravimetric method. Meanwhile, the drug re-lease behaviors of bovine serum albumin (BSA) contained in (P(AAPBA-co-DMAEMA) hydrogels under different conditions were explored. The main results were shown as follows:1 P(AAPBA-co-AAm) was preprared by free radical polymerization using am-monium persulfate (APS) as an initiator in N,N-dimethylformamide (DMF) aqueous solution, The complex behavior between P(AAPBA-co-AAm) and PVA in aqueous solution was studied by UV transmittance measurement. The results showed that (1) When the concentration of P(AAPBA-co-AAm)/PVA (with the same mass ratio) in aqueous solution was less than 2 wt%, the system was sol state, otherwise, the system was gel state. (2) The cooperative interaction between P(AAPBA-co-AAm) and PVA was weakened as salt concentration of the solution increased. (3) The increase of sug-ar concentration in solution destroyed the complex formation between P(AAPBA-co-AAm) and PVA. (4) P(AAPBA-co-AAm)/PVA matrix showed from gel to sol transition when certain amount glucose was added.2 P(AAPBA-co-DMAEMA) hydrogels were preprared by free radical polymeri-zation using APS as an initiator and N,N'-methylene bisacrylamide (NNMBA) as a crosslinker in DMF aqueous solution. pH, temperature and glucose sensitivity of the hydrogels was investigated and the drug release behaviors under different conditions were also explored. The results showed that (1) The equilibrium swelling ratios of the P(AAPBA-co-DMAEMA) hydrogels were significantly affected by the pH of the swelling media. (2) All the P(AAPBA-co-DMAEMA) hydrogels demonstrated a sim-ilar swelling profile as temperature of the swelling medium changes, viz. a fall in swelling ratio with temperature, which becomes sharper in the vicinity of the LCST of the P(AAPBA-co-DMAEMA) hydrogel. Finally, in the high temperature regime, all of the system display almost complete deswelling and equilibrium swelling ratios (ESR) attain a value close to unity. (3) P(AAPBA-co-DMAEMA) hydrogels showed swelling changes with time in a glucose concentration-dependent manner. (4) The re-lease of BSA from the P(AAPBA-co-DMAEMA) hydrogels depended on the pH, temperature and glucose centration of the release medium.3 Water-solubleβ-CD/EPI was prepared by polymerization betweenβ-cyclodextrin (β-CD) and epichlorohydrin (EPI) in alkaline environment. (P(AAPBA-co-DMAEMA)/(β-CD/EPI)) semi-IPN hydrogel was prepared by free radical solution polymerization using APS as an initiator and NNMBA as a crosslink-er in DMF aqueous solution. pH, temperature and glucose sensitivity of the hydrogels were investigated under diffierent conditions. The results showed that (1) When the dosage ofβ-CD/EPI in (P(AAPBA-co-DMAEMA)/(β-CD/EPI)) semi-IPN hydrogels was more than 25 wt%, the hydrogels showed poor mechanical strength and easy fragmentation after swelling. (2) The equilibrium swelling ratios of the (P(AAPBA-co-DMAEMA)/(β-CD/EPI)) semi-IPN hydrogels were significantly af-fected by the pH, temperature and glucose concentration of the swelling media changes and they also showed the salt sensitivity.