Development of a novel pH-sensitive polymer matrix for drug encapsulation from maleated poly(vinyl alcohol) grafted with polyacrylamide

摘要

Hydrogels are widely used in medical, food and other applications due to their good water absorption without dissolution. The objective of this work was to synthesize a maleated poly(vinyl alcohol) (PVAM) grafted copolymer with anionic polyacrylamide (PAM) (PVAM-graft-PAM) using K2S2O8 as an initiator in an eco-friendly process. The chemical structure of the PVAM-graft-PAM was confirmed by FTIR. The influences of the PVAM/PAM ratio and the natural rubber-graft-cassava starch (NS) and PVAM/PAM ratio on the properties of the PVAM-graft-PAM were investigated. It was observed that the swelling ratio of the sample was enhanced with increasing PAM portions in the PVAM-graft-PAM. However, as the quantity of NS in the graft copolymer increased, the swelling ratio decreased. In addition, the PVAM-graft-PAM was sensitive to variation in pH due to the presence of carboxylic and amide groups on the grafting structure. After the preparation of the PVAM-graft-PAM, it was used in the controlled release of retinoic acid. After use, the resulting hydrogel degraded easily in natural soil.