Enhanced adhesion of novel biomass-based biomimetic adhesives using polyaspartamide derivative with lignin

With the decreasing of petrochemical resources and the increasing severity environmental pollution, the development of environmentally friendly adhesive technology using renewable resources has attracted more and more attention. Inspired by mussels, a novel biomimetic adhesive synthesized using polyaspartamide derivative (PolyAspAm(DOPA/OA)) and alkali lignin (AL). The physical/chemical structure and properties were examined by 1H-NMR, Fourier-transform infrared spectroscopy, thermo gravimetric analysis, scanning electron microscopy, water absorption, in vitro cytotoxicity, lap shear tensile, and three-point bending tests. The adhesive capacity was improved significantly when AL added into PolyAspAm(DOPA/OA). The lap shear tensile for four different substrates (metal and plastic) both increased greatly. The underwater adhesion test possessed good underwater adhesion properties. The results confirmed that hydrogen bonds and chain entanglement were formed between PolyAspAm(DOPA/OA) and AL. It was the introduction of catechol groups and physical-chemical interactions between PolyAspAm(DOPA/OA) and AL improved the adhesion strength and water resistance of the adhesive. Moreover, the corn stover non-wood boards were prepared by one-step hot pressing using PolyAspAm(DOPA/OA) with AL adhesives. The three-point bending of corn stover non-wood boards increased from 5.00 +/- 0.03 to 14.85 +/- 20.1 MPa. Overall, this work shows that a nontoxic, environmentally friendly PolyAspAm(DOPA/OA) with AL adhesive has extensive application prospects. Schematic illustration of the biomass-based biomimetic adhesives mechanism. image