Synthesis of graphene oxide–methacrylic acid–sodium allyl sulfonate copolymer and its tanning properties.

Graphite oxide nanosheets (GONs) and the copolymer of GONs with methacrylic acid (MAA) and sodium allyl sulfonate (SAS) (poly(GON–MAA–SAS)) were prepared. The GONs in poly(GON–MAA–SAS) are smaller and uniformly dispersed, allowing them to penetrate into collagen fibers of leather and produce better tanning effects than current nano-tanning agents. Tanning effects due to chemical bonding and nanoeffects are elucidated by measuring the shrinkage temperature (T s) of wet and dry leather. The results indicate that poly(GON–MAA–SAS) could be used alone as a tanning agent to provide excellent mechanical properties, especially good elasticity and softness, although the T s is slightly lower than that of chrome-tanned leather. Poly(GON–MAA–SAS) in combination with a chrome tanning agent could allow the dosage of the latter to be halved. These results indicate the potential for new nano-tanning agents to reduce the pollution caused by tanning agents. [ABSTRACT FROM AUTHOR]