Hydrophobization of Cellulose Sheets by Gas Grafting of Palmitoyl Chloride by Using Hot Press

[Display omitted] •High hydrophobic cellulose sheet was produced by gas grafting using hot press.•The hydrophobization of cellulose was improved by controlling hot pressing conditions.•The hydrophobization of cellulose was improved by adjustment of air resistance.•The pressing pressure was a key factor for the hydrophobizaiton of cellulose. The purpose of this study was to investigate the improvement in the hydrophobicity of cellulose through gas grafting treatment with long chain fatty acid chloride using high pressure during pressing at high temperature. To do this, the gas grafting treatment was performed on the cellulose sheet using a hot pressing method, and then the hydrophobization effect was analyzed. It was found that the gas grafting treatment by hot pressing using high pressure during pressing at high temperature produced cellulose sheets of high hydrophobicity. Especially, it was notable that the hydrophobization efficiency enhanced with an increase of the pressing pressure. In addition, the gas grafting efficiency was improved when polyvinyl alcohol (PVA) was coated to obtain high resistance to air permeability. These results indicate that protecting the loss of fatty acid gas by coating of polyvinyl alcohol (PVA) on the cellulose sheet surface contributed to the improvement of gas grafting efficiency.