Preparation of cellulose nanomaterials and their application in the modification of polyacrylate latex

In this work, carboxymethyl cellulose nanofiber (CCNF), hydroxypropyl cellulose nanofiber (HCNF) and nanocrystalline cellulose (NCC) were prepared independently, and their structures, the solution and sizing properties of their composite emulsion with polyacrylate latex (NA) were studied. The findings revealed that CCNF and HCNF were of cellulose nanofibers, whereas NCC was of cellulose nanocrystal, and their aqueous dispersions had excellent stability under neutral conditions. Incorporating each of CCNF, HCNF and NCC in a small quantity into NA could not only reduce the latex particle size, improve the rheological and comprehensive sizing performances of NA, but also reduce the moisture absorption rate, enhance the tensile strength and Young's modulus of the film formed by NA latex. However, nanocellulose with diverse morphology and structure exhibited distinct effects, among which the nanofiber CCNF with a higher aspect ratio demonstrating the most significant modification effect. Based on the results of single-factor experiments, the sizing process of the composite latex CNA (NA modified by CCNF) was optimized through the response surface method. The result revealed that the comprehensive sizing performances of the optimized CNA were still significantly better than that of NA under the conditions of reducing size percentage and sizing temperature, indicating that the optimized CNA could offer advantages in energy conservation and emission reduction.