Polymer-coal composite as a novel plastic material

•Novel composite polymer film was prepared from coal, starch and polyvinyl alcohol.•New polymeric plastic material was prepared though hydrogen bonding.•The novel plastic films exhibited good mechanical and thermal stabilities.•These plastic films can be used as biodegradable plastic bags and mulch films. Novel composite polymeric material was prepared from coal, carboxymethyl starch (CMS) and polyvinyl alcohol (PVA). Coal was first treated with NaOH to partially dissolve the coal into sodium humate (SH) and the SH along with undissolved residue was blended with CMS and PVA solution to prepare a polymeric composite though hydrogen bonding. The composite materials showed tensile strength in the range of 8–10MPa for potential applications including plastic bags and films. The residue after coal dissolution in NaOH served as filler while the SH led to bonding with CMS/PVA in water though hydrogen bonds as detected by Fourier Transform Infrared (FTIR) spectroscopy and X-ray Photoelectron Spectroscopy (XPS).