A novel thermally-activated crosslinking agent for chitosan in aqueous solution: a rheological investigation

摘要: The use of 2,5-dimethoxy-2,5-dihydrofuran (DHF) as a temperature-controlled gelation agent for chitosan under acidic conditions has been examined by dynamic oscillatory and viscometry techniques. In particular, the rate extent have over range different temperatures (40–98 °C), DHF concentrations (10–100 mM) pH (0.9–2.1). time, tG, decreases, maximum increases substantially function rising temperature. When fit with simple Arrhenius function, tG data yield an activation energy 55±8 kJ mol-1. Gelation is found to occur on shortest time-scale, strongest gels result, at highest investigated. Similarly, gel strength are most solution examined. Experimental findings interpreted in terms competition between crosslinking reaction (which drives formation, initially dominant) protolytic decomposition disrupts structure, becomes increasingly important time progresses). Syneresis phenomena additionally impact results obtained ≥50 mM.