Surface Modification of Nanocrystalline Cellulose and Its Application in the deinked pulp

摘要

In this study, nanocrystalline cellulose (NCC), isolated from the bleached aspen kraft pulp, was surface modified using borate. The resultant nanocrystal suspensions, namely BNCC, were characterized by conductometric titration and atomic force microscope (AFM). B-NCC was then applied as a retention aid in the bleached old newsprint deinked pulp. The results showed that the modification process led to a negative increase in surface charge density, while the particle size was not changed. The fines retention and pulp drainability were increased when the BNCC was used either alone as the monocomponent retention aid, or together with cationic polyacrylamide (CPAM) to constitute a microparticle retention system. The microparticle retention system gave better retention and drainage rate, with the maximum values of 90.5% and 3.5 ml/s, respectively.