Study of water vapor sorption by cellulose esters with different degrees of substitution

In this research, the sorption of water vapor (WV) by various cellulose esters with different degrees substitution (SD) has been studied. It was found that if value is measured in moles H2O per mole repeating units esters, then properties depend only on degree and not type substituent. The lowest observed for triesters due to absence hydroxyl groups, which have greatest contribution process. To describe isotherms, a calculating equation A = Ao(1- K lnφ)-1 derived, where Ao maximum at relative pressure φ=1, coefficient. This allows adequately describing experimental S-shaped isotherms WV having SD. shown most probable mechanism binding polar molecules groups esters.