초록 |
This experiment describes the synthesis and characterization of intramolecular cross-linked boronic acid in acidic pH and reversibly decomposing in basic pH with pentaerythritol. In boronic acid and diol complexation, which is depended on pKa value of boronic acid, intermolecular cross-link occur superiorly in normal concentration. However, we demonstrated that the internal coordination aided to stabilize intramolecular cross-linked form at acidic pH, because of grafted polymer, when both were dispersed at dilluted water solution. The protected phenylboronate ester-containing grafted polymer was not only prepared by ATRP on PHEMA backbone, but also transformed to boronic acid brush by hydrolysis, which was determined by GPC and 1H NMR spectroscopy. Reversible cross-linking and decomposition were characterized by DLS at 0.00005 wt% polymer in solution. This tailored coordination that can be transformed by change in pH is anticipated to encourage for drug delivery system. |