Beeswax emulsions and microcapsules for hydrophobic modification of cellulose fiber networks
University of New Brunswick
Various beeswax emulsions and beeswax-based microcapsules were developed in an attempt to reduce the water vapor transmission rate (WVTR) of cellulose fiber networks of paper products which are of great importance for green-based packaging materials. Four different systems were established and investigated: the block polymer (PE-b-PEG) stabilized beeswax emulsion, cationic starch-stabilized beeswax emulsion, nanobentonite-stabilized beeswax emulsion, and starch microcapsules loaded with beeswax. Each emulsion system or latex was applied to paper handsheets via wet-end addition, surface coating or the combination of wet-end addition and coating. The resulting paper products were well characterized with particular attention paid to WVTR measurements. According to the ASTM E-96, a wet-cup method was developed to quantify the WVTR values at the condition of 38°C and 90% relative humidity (RH). The results indicated that the hydrophobic modification of fiber networks increased the hydrophobicity of paper substantially and reduced the WVTR by 70%. The combination of wet-end addition and surface coating creates the synergy in lowering WVTR.