High-added-value biomass-derived composites by chemically coupling post-consumer plastics with agricultural and forestry wastes

Currently, the ever-increasing post-consumer polypropylene (PP) plastics and agricultural and forestry wastes that are relatively difficult to be degraded have led to serious resource waste and environmental pollution. To achieve the rational utilization of resources and meanwhile reduce the potential influences on ecological environment, in this study, high-added-value biomass-derived composites were produced by chemically coupling post-consumer plastics with agricultural and forestry wastes (e.g. pine nutshell and corn straw) in the presence of interfacial compatibilizers. In terms of chemical composition, the as-proposed compatibilizer contains C[dbnd]C bonds and N[dbnd]C[dbnd]O group, which can be effectively enhance the interfacial compatibility and mechanical stability of hydroxyl-rich biomass wastes and plastics. Experimental results conclude that the highest tensile strength of forestry pine nutshell/PP composite is 25.44 MPa and the flexural strength is 47.84 MPa with the assistance of 5.0 wt% compatibilizer. If agricultural corn straw is used as the raw materials, the highest flexural strength of corn straw/PP composite is 42.94 MPa and the tensile strength is 22.60 MPa under the same experimental conditions. Besides the improved mechanical properties, the thermal stability and water retardation capacity of the produced biomass-waste/PP composites is enhanced with the addition of the chemical compatibilizer as confirmed by thermal gravimetric analysis and water absorption measurements. This conversion of the post-consumer plastics and the biomass wastes into the environmentally benign high-added-value composite materials is favorable to promote the recycling economy and achieve the recyclable utilization of these wastes that are harmful to environment.