CRITICAL CONCENTRATIONS OF α-(1→3)-D-GLUCAN FROM LENTINUS EDODES IN NaOH AQUEOUS SOLUTION

• 来源期刊: 高分子科学（英文版）
• 年，卷（期）: 2000,（6）
• 页码范围: 501-507
• 页数: 7页
• 语种: 英文

摘要

Critical concentrations of α-(1→3)-D-glucan L-FV-Ⅱ from Lentinus edodes were studied by viscometry and fluorescence probe techniques. The dependence of the reduced viscosity on concentration of the glucan in 0.5 mol/L NaOH aqueous solutions with or without urea showed two turning points corresponding to the dynamic contact concentration cs and the overlap concentration c* of the polymer. The values of cs and c* were found to be 1 × 10-3 gcm-3 and 1.1 × 10-2 g cm-3,respectively, for L-FV-Ⅱ in 0.5 mol/L NaOH aqueous solutions. The two critical concentrations of L-FV-Ⅱ in 0.5 mol/L NaOH aqueous solutions were also found to be 1.2 × 10-3 g cm-3 for cs and 9.2 × 10-3 gcm-3 for c* from the concentration dependence of phenanthrene fluorescence intensities. The overlap concentration c* of L-FV-Ⅱ in 0.5 mol/L NaOH aqueous solutions was lower than that of polystyrene with same molecular weight in benzene, owing to the fact that polysaccharide tends to undergo aggregation caused by intermolecular hydrogen bonding. A normal viscosity behavior of L-FV-Ⅱ in 0.5 mol/L urea/0.5 mol/L NaOH aqueous solutions can still be observed in an extremely low concentration range at 25℃.