Functional fibers from regenerated wood pulp cellulose and a natural‐based phytate with enhanced flame retardancy properties

The manufacture of sustainable functional fibers with low environmental footprint and superior properties is a pressing research issue under the auspices of more sustainable industrial textile processes. In the present study, regenerated cellulose fibers (CellReg) with flame retardancy properties are manufactured by functionalizing regenerated wood pulp fibers (obtained through the dissolution of paper‐grade pulp in an ionic liquid followed by regeneration in water) with a natural derived phosphorus compound, namely phytic acid ammonium (PAA). The pale‐yellow modified fibers present a phosphorus content up to 1.80% and a uniform and smooth surface morphology. Furthermore, the functional cellulose fibers exhibit moderate antioxidant activity (ca. 18.4% of maximum radical scavenging), water contact angles below 92°, as well as good thermal‐oxidative stability up to 200°C. The flame‐retardant performance of the CellReg/PAA fibers was investigated by the vertical burning test, and as anticipated, the results show a higher flame retardancy with the increasing content of phosphorus, meaning that the fibers ceased to burn before flaming or glowing, even after several flame applications. The accomplished properties validate the potential of these functional fibers of regenerated wood pulp cellulose and PAA for application as textile fibers with flame retardancy properties. Regenerated wood pulp cellulose, functionalized with a natural‐based phytate, namely phytic acid ammonium, originates pale yellow fibers with a uniform and smooth surface morphology, antioxidant activity, thermal‐oxidative stability, and char‐forming flame‐retardant properties. The resultant functional fibers, with low environmental footprint and flame retardancy, can be an alternative to synthetic and cotton fibers for flame‐retardant textile applications.