Effects of sacrificial coordination bonds on the mechanical performance of lignin-based thermoplastic elastomer composites.

Abstract

The coordination-based energy sacrificial bonds have been constructed in the interphase between lignin and polyolefin elastomer which has been demonstrated as an effective method to prepare high performance lignin-based thermoplastic elastomers (TPEs). Here, we proposed a strategy of adjusting the strength and toughness of lignin-based TPEs by using different nitrogen heterocyclic compounds as reactive assistants and Fe3+ or Zn2+ as metal coordination centers to construct coordination bonds between lignin and polyethylene elastomer matrix. It was demonstrated that 3-Amino-1,2,4-triazole with three nitrogen atoms in the heterocyclic ring and one nitrogen branch chain could form the most efficient coordination bond system which generated the best mechanical performance. The system with ferric iron as coordination center exhibited better enhancement effect than divalent zinc. By adjusting the nitrogen-containing reactive additives or metal salts as coordination centers, the mechanical performance of the lignin-based TPE can be regulated, which provides a method for making green bio-composites with good strength and toughness.