Experimental investigation on self-activated healing performance of thermosetting polyurethane prepared by tungsten (VI) chloride catalyst

Abstract

Polymers and polymeric composites are widely used for various applications due to their outstanding and wide range of properties. Polyurethanes, existing in different types, are novel and versatile polymers with excellent mechanical properties. Thermosetting polyurethane resins are among the most widely used polyurethanes wherein their manufacturing and developing have been introduced during the last few years. Self-healing materials have been inspired by biological systems in which damages provoke healing responses. It is almost cost-effective to use self-healing materials in commercial applications. This study investigates a novel self-activated approach in thermosetting polyurethane resins. A tungsten (VI) chloride (\({{\rm{WCl}}}_{6}\)) catalyst, a co-activator (phenylacetylene) and a dissolution agent (nonylphenol) were used for the onset of ring-opening metathesis polymerization of dicyclopentadiene. Here different percentages of a catalyst in polyurethane resins were used, the impacts of which on fracture toughness and healing efficiency were also studied. To examine healing efficiency, samples with tapered double-cantilever beam geometry were prepared and using the self-activated method, the development of thermosetting polyurethane self-healing was investigated. The results showed that the concentration of catalyst affects the basic properties of the material and healing efficiency of the composite. The highest healing efficiency of 97% was obtained for a 3 wt% catalyst.