Effect of surfactants on the cellulosic fiber characteristics during paper recycling

As a kind of chemical additives, surfactants are widely used in the processes of papermaking, which played roles of wetting, dispersing, emulsifying etc. to adjust and maintain the product performance. However, there are few reports about the effect of surfactants on fiber properties, especially during paper recycling. This work investigated the effects of three types of surfactants on the cellulosic fibers and paper properties during five-time recycling. Properties of recycled paper with five times were presented as the index of papermaking potential. The results showed that cetyl trimethyl ammonium bromide (CTAB), a cationic surfactant, had an obvious negative effect on paper properties. For continuous surfactant supplements, the burst, tearing, and tensile index decreased by 50.2%, 41.6%, and 43.6%, respectively. Sodium dodecyl benzene sulfonate (SDBS), an anionic surfactant, had a significant positive effect on fibers' WRV and inhibited the fibers' hornification to some extent. However, it had a negative effect on paper properties by affecting the bonding between the fibers. Triton X-100 (TX-100), a nonionic surfactant, improved paper properties according to the papermaking potential. For adding surfactant only once, the burst, tearing, and tensile index increased by 15.0%, 8.59%, and 7.2%, respectively. For these three types of surfactants, TX-100 was generally more beneficial for fiber and paper. This paper revealed the effects of surfactants on the fiber and paper properties and perfected the theory of surfactants applied for fiber and paper in papermaking.