合成多糖質のシアノエチル化と生成物の誘電特性

抄録

Polycondensation of D-glucose with polyphosphoric acid (PPA) as a condensation agent in dimethyl sulfoxide (DMSO) has been studied. The reaction conditions under which a colorless synthetic glucan was obtained were temperature of 50°C and reaction time of 12 hours. The characteristics of the synthetic glucan were as follows: yield 44.1%, specific rotation +59.8° and degree of polymerization (DP) 148.1. This synthetic glucan combined less free phosphorus, 6 monoester phosphoruses and 20-24 diester phosphoruses per 100 glucose residues. The structure of synthetic glucan was studied by the method of the peroxidation and the Smith degradation, and the results suggested that the modes of glucose condensation were C1-C'6, C1-C'3 and products had many branched chains. The synthetic glucans were cyanoethylated, and the maximam DS of cyanoethyl group was 1.90. Dielectric constant and loss of these derivatives at various frequencies and temperatures were measured. The peak of dielectric loss which was due to side chain relaxation of cyanoethyl group at -50°C was observed, and the activation energy of this side chain relaxation was calculated to be 66.1kJ/mol.