Biodegradable regenerated cellulose-dispersed composites with improved properties via a pickering emulsion process

•RC/PLA composites were prepared by a Pickering emulsion process.•RC is treated as a reinforcing agent in the field of green nanocomposites.•RC can enhance the crystallization performance of PLA.•RC/PLA composites have a high strength and optical transparency. Reinforcement of biodegradable polymers with nanocellulose is attractive yet the effectiveness is often compromised by uneven dispersion. In this work, a general method of preparing reinforced biodegradable composites using regenerated cellulose (RC) was developed. From an oil-in-water Pickering emulsion of PLA/methylene chloride stabilized with RC, uniformly dispersed RC/PLA composites was obtained. The resulting RC/PLA composites showed enhanced crystallization and tensile strength of up to 34% compared with the native PLA, while the transmittance in the visible range remained above 70%. The Pickering emulsion-based composition procedure is simple, environment friendly and cost effectively, which could be applied to preparation of other RC-reinforced biodegradable composites.