Different Kinds of Microfibrillated Cellulose as Coating Layers Providing Fiber-based Barrier Properties

keywords:microfibrillated cellulose  coating performance  surface properties  barrier properties

Abstract:In this study, we investigated the barrier properties of different kinds of microfibrillated cellulose (MFC) coating layers. The air, oxygen, and water vapor permeability, as well as the water contact angles (WCA), were measured to quantify the barrier efficacy of the applied coatings. The WCA data showed that the surfaces of MFC-coated cardboards are more hydrophilic than those of uncoated cardboards. However, different MFC coatings realize different oxygen transmission rates (OTRs) and water vapor transmission rates (WVTRs). The MFC coating derived from bleached bamboo pulp subjected to carboxyethylation pretreatment (MFC_CBP) gave the best oxygen and water vapor barrier performances. The OTR of the virgin cardboard (>16500 cm³/(m²·24 h)) decreased to 4638 cm³/(m²·24 h) after coating with the MFC_CBP. The WVTR similarly decreased from 1016.7 g/(m²·24 h) to 603.2 g/(m²·24 h).