Comprehensive Analysis of the Substituent Distribution in the Glucosyl Units and along the Polymer Chain of Hydroxyethylmethyl Celluloses and Statistical Evaluation

摘要: Hydroxyethylmethyl celluloses (HEMC, DSMe 1.46−1.66, DSHE = 0.14−0.17) have been analyzed with respect to their methyl and hydroxyethyl pattern in the glucosyl units along polymer chain. Methyl groups were located by GLC/MS after direct hydrolysis, reduction, acetylation, distribution of residues could be determined enhanced sensitivity permethylation unify a certain HE occurring combination various patterns single peak. To get insight into Me cellulose chain, method was developed which overcomes strong discrimination relative ion intensities caused hydroxyalkyl enables quantitative determination oligomer composition random degradation for first time. This comprises perdeuteriomethylation; partial acid hydrolysis; reductive amination propylamine; and, finally, yield completely O- N-alkylated, permanently cha...