Preparation of robust aramid composite papers exhibiting water resistance by partial dissolution/regeneration welding

Aramid fibers exhibit impressive mechanical properties, electrical insulation properties, and chemical stability. However, physical properties of the aramid paper are poor because of the chemical inertness and smooth surface of aramid fibers. This study reports a simple and efficient method for substantially improving the performance of the para-aramid/meta-aramid composite paper by introducing the N,N-dimethylacetamide (DMAc)/LiCl solution to induce partial dissolution or by adding the DMAc/LiCl/para-aramid solution to induce regeneration. Experimental results state that the tensile strength, specific strength, folding resistance, and interlayer bonding strength of the aramid paper are increased by 2.17, 2.13, 34.7, and 9.39 times, respectively, because of the dense and compact structure of the paper. Furthermore, the water resistance of the paper was also considerably improved. After immersing the paper samples in water for 24 h, their moisture absorption rate decreased to approximately 54% from approximately 143% for the original paper. Results indicate that partial dissolution/regeneration welding is a viable method for the efficient reinforcement of the aramid composite paper, providing additional possibilities for manufacturing the high-performance aramid paper-based materials.