Optimization of Mechanical and Self-Healing Properties of Thermally Reversible Self-Healing Polymer Composites

Self-healing polymers, used as the resin in polymer composites, are capable to recover their original properties, after subjecting to initial damage. In the present study, the effects of various parameters including the weight fractions of self-healing resin and hot-cured resin, healing temperature, applied pressure and time on the mechanical properties and self-healing properties of thermally reversible (Diels-Alder) self-healing composites are investigated experimentally. Then, the highest healing efficiency was calculated by considering appropriate mechanical properties. For this purpose, first, using the design of experiments method (DOE), the levels of different effective parameters were determined. For each of the eight experiments designed by the Taguchi method, three four-point bending specimens were fabricated with three replicates. Then the mechanical properties are determined by using four-point bending tests. For the damaged specimens, the initial damage was generated by a tensile test and then the specimens were heated to complete the healing cycle. Mechanical properties of healed specimens were also determined by a four-point bending test and by comparing with control specimens their healing efficiencies were calculated. The experimental results showed the effects of each parameter on the mechanical properties and self-healing properties of the composites and also determined the optimum amount of each parameter.