Synthesis and characterization of temperature/pH dual sensitive hemicellulose-based hydrogels from eucalyptus APMP
Ting Chen1, Haitang Liu2, Cuihua Dong3
1China Light Industry Key Laboratory of Papermaking and Biorefinery, Tianjin Key Laboratory of Pulp & Paper, Tianjin University of Science and Technology, Tianjin 300457, China; College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China.
Abstract:
In this investigation, a variety of innovative temperature/pH-sensitive hydrogels consisting of hemicellulose (extracted from APMP waste liquor) and acrylic acid/acrylamide monomers were synthesized via free radical polymerization for water retention agents and controlled release. The results showed that the hydrogel polymer was chemically cross-linked and entangled to form a three-dimensional network structure, and the monomer successfully grafted on the hemicellulose chain. The content of crosslinkers and monomers had obvious effects on the swelling ratio of hydrogel. The sensitivity of the hydrogel was determined according to the change of the swelling ratio of the hydrogel under different temperature and pH conditions, combined with the chemical structure analysis of the hydrogel, and explain its sensitivity mechanism. Finally, after 6 days at 25 °C and pH 6, the swelled hydrogel still retained 79.46 % of the moisture, which proved that it has high water retention ability.
