pH- and Temperature-Responsive Chitosan-g-PDMAEMA as an Active Coating Material and Its Effects on the Storing of Grape

The pH- and temperature-responsive chitosan-graft-poly(2-(dimethylamino) ethyl methacrylate) (CS-g-PDMAEMA) were synthesized via atom transfer radical polymerization (ATRP) and evidenced by FTIR spectroscopy. Chitosan macroinitiator (CS-Br) was prepared by phthaloylation of amino groups of chitosan and acylation of hydroxyl groups of chitosan with 2-bromoisobutyryl bromide. The pH and temperature responses of the copolymer micelles were characterized by particle diameter and particle size analyzers. The film prepared from CS-g-PDMAEMA was used as a coating film on the surface of the grape. And the film prepared from 1 wt% CS-g-PDMAEMA solution was able to slow the loss of water in grape. The results revealed that the CS-g-PDMAEMA had potential application as active coating materials in the storage of fresh grape.