Possibility of hydrogen bonding between AKD and cellulose molecules during AKD sizing

Regioselectively substituted 2,3-di-O-methylcellulose (23MC) was used as cellulose model in blends with alkylketene dimer (AKD). The interaction between sizing materials (AKD and its hydrolyzed product, h-AKD) and cellulose were examined by the analyses of FTIR spectroscopy. This model study showed that the primary hydroxyl groups at C-6 position of 23MC were engaged in hydrogen bonding with lactone oxygen in AKD or its ketone molecule. In addition, these hydrogen bonds formed in the AKD/23MC or h-AKD/23MC blends could be rearranged during drying and heating treatment because long alkyl chain of AKD covalently linked with 23MC disturbs the hydrogen bonding by increasing in their free hydroxyl groups.