Modification of Microfibril Surfaces

The hydroxyl groups in the surface of cellulose fibrils offer rich possibilities for chemical modification. Fibrils are partially amorphous and MFC prepared from chemical pulps will be microporous due to the removal of lignin and hemicelluloses. To avoid unacceptably high consumption of reactants, surface modification reactions should therefore be designed so that penetration of chemicals into the fibrils is avoided. 

Surface modification of fibrils reported in the literature are mainly hydrophobica-tion reactions aimed at compatibilization with nonpolar polymer matrices. Hence, much of the work concerns modification of whiskers that are easier to mix into composites than MFC. However, methods for introduction of specific functionalities, as part of other applications of MFC, have also been reported. 

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