Blending of cellulose nanofibers with cotton linter pulp to enhance the mechanical and barrier properties of paper

This study investigated the use of cotton linter pulp with the blending of cellulose nanofibers (CNFs) to produce paper with improved functional attributes. The CNFs were added to cotton linter pulp in varying proportions (0, 20, 40, 60, 80, and 100% on a dry weight basis). The paper handsheets of 60 ± 1 g/m² were prepared and evaluated for surface morphology, crystallinity, mechanical, barrier, and optical properties. Surface morphology revealed the high compactness of paper incorporated with CNFs. No significant changes in the surface roughness of the paper were observed upon the addition of CNFs. Mechanical properties substantially improved with CNF loading, leading to a notable increase in tensile strength (3.6-9.4 fold), tearing resistance (1.6-2.1 fold), bursting strength (1.1-4.2 fold) and folding endurance (6-184 fold) compared with control paper. The CNFs blending caused a marked reduction in Cobb value (up to 63.3%) and increased air resistance (up to 34.3%), demonstrating the high barrier properties of paper. The optical properties showed a decrease in brightness (up to 31.8%) and variable opacity trends with the addition of CNFs. The findings suggested cotton linters are suitable for producing high-quality specialty paper. The research ascertained the potential of CNFs as a sustainable green material to enhance the mechanical and barrier performance of paper products.