Cellulose hydroxyl groups urethanated

Surface Concentration, Cs, of the Hydroxyl Groups Urethanated for Cellulose and PVA Films and Surface Area, As, per Hydroxyl Group... 

In bonding wood, the reaction of isocyanate groups with the numerous hydroxyl groups that are present in the various components of wood—cellulose, hemicellulose, and lignin—is possible. The product of this chemical reaction with wood is the urethane bond as shown in Reaction I. Methyl, ethyl, propyl, and butyl isocyanates... 

Reactions involved in this sol-gel process are the same to those previously described for polyurethanes, except that a macromolecular polyol has replaced the monomeric one (Figure 10.4). The hydroxyl groups of the cellulose acetate react with the NCO groups of the isocyanates to form urethane linkages (Figure 10.21). Those reactions, which actually have been studied for a long time [62], yield to chemical species referred to as cellulose carbamates. Because of the rather large proportion of secondary alcohols in... 

If wood is treated with an adhesive containing an isocyanate, it is possible that these would react with hydroxyl groups on cellulose or lignin to produce urethane linkages as shown below ... 

Hydrogen bonding is particularly important in polymers and copolymers containing the following functional groups amide (polypeptides, proteins, polyamides), urethane (polyurethanes), hydroxyl (cellulose, polyvinyl alcohol), and carboxyl (polyacrylic acid). 

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