Rod-like Cellulose Regenerated by Bottom-Up Assembly in Natural Rubber Latex and Its Reinforcement

• Published in: International journal of molecular sciences Vol. 24; no. 7; p. 6457
• Main Authors: Yuan, Haoze, Li, Peixing, Wang, Xinyu, Zhao, Hongying, Sun, Jutao
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 30-03-2023; MDPI
• Subjects: Acetic acid; Acids; Alkalinity; Aqueous solutions; bottom-up; Cellulose; cellulose solution; Coagulants; Crystallization; Crystals; Energy consumption; Excipients; Interfacial bonding; Latex; Latex - chemistry; Mechanical properties; Natural rubber; natural rubber latex; Organic acids; Polymers; regenerated cellulose; Rubber; Rubber - chemistry; Rubber industry; Self-assembly; Tensile strength; Tensile tests; Water; China; natural rubber latex; cellulose solution; bottom-up; regenerated cellulose
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms24076457

As a renewable biomass material, nano-cellulose has been investigated as a reinforcing filler in rubber composites but has seen little success because of its strong inclination towards aggregating. Here, a bottom-up self-assembly approach was proposed by regenerating cellulose crystals from a mixture of cellulose solution and natural rubber (NR) latex. Different co-coagulants of both cellulose solution and natural rubber latex were added to break the dissolution equilibrium and in-situ regenerate cellulose in the NR matrix. The SEM images showed that the sizes and morphologies of regenerated cellulose (RC) varied greatly with the addition of different co-coagulants. Only when a 5 wt% acetic acid aqueous solution was used, the RC particles showed an ideal rod-like structure with small sizes of about 100 nm in diameter and 1.0 μm in length. The tensile test showed that rod-like RC (RRC)-endowed NR vulcanizates with pronounced reinforcement had a drastic upturn in stress after stretching to 200% strain. The results of XRD and the Mullins effect showed that this drastic upturn in stress was mainly attributed to the formation of rigid RRC-RRC networks during stretching instead of the strain-induced crystallization of NR. This bottom-up approach provided a simple way to ensure the effective utilization of cellulosic materials in the rubber industry.