Polycondensation of cyclodextrins with epichlorohydrin. Influence of reaction conditions on the polymer structure

A series of water-soluble polymers was synthesized by polycondensation of cyclodextrin with epichlorohydrin under basic conditions. We studied their molecular distribution as a function of molar ratios of reactants. NaOH concentration showed that very high molecular averages (Mw > 10⁶) can be obtained. The substitution patterns were determined by ¹³C NMR analysis and standard methylation analysis of polysaccharides. The formation of side chains and bridges consisting of sequences of poly(2-hydroxypropyl)ether units were demonstrated by electrospray ionization mass spectrometry and gas liquid chromatography-mass spectrometry. The predominant position of substitution depends on the NaOH concentration.