Hemicellulose beta-ketoester prepared by reaction with alkyl ketene dimer and its self-emulsifying properties

To make use of the byproduct in dissolving pulp production, hemicellulose collected from waste water was used to modify alkyl ketene dimer (AKD), confirmed by FT-IR and NMR analysis. The obtained product ACMHC exhibited self-emulsifying in absence of extra surfactant when emulsion was prepared. The obtained ACMHC emulsion (10 %) showed small droplet diameter of 0.8 mu m and high zeta potential of - 40 mV. The effects of ionic strength, pH, temperature and long-term storage on properties of the emulsion were investigated. In emulsification long alkyl groups from AKD formed the core while hemicellulose formed the shell. Due to electrostatic repulsion and steric repulsion from the shell, ACMHC emulsion stayed stable. Furthermore, ACMHC emulsion was applied on paper to evaluate its influence on barrier properties. Oil barrier grade of the coated paper was increased from 0/12 to 5/12 and water contact angle reached 108.5 degrees at a coating amount of 6.11 g/m2. These results demonstrated self-emulsifying AKD emulsion could be achieved by combining hemicellulose and AKD and the resultant emulsion could potentially serve as coatings for paper materials for enhancing barrier properties.