Study the self-healing properties of sol-gel coatings containing reversible tetra sulfide groups

Sol-gel protective coatings draw many attentions since they are low temperature productive, versatile chemically structure and user-friendly. Protective self-healing coatings provide longer life-time and less maintenance and repair's cost via healing the damages autonomically and non-autonomically. In this study, self-healing hybrid sol-gel coatings containing reversible tetra sulfide, synthesized and studied. The effect of the reversible group’s content and the crosslinking density on the thermal, mechanical and healing properties of the developed sol-gel polymers are presented. The prepared hybrid sol-gel polymers exhibited thermal stability in the S-S bond cleavage temperature window and a significant gap closure capability at modest temperatures. The gap closure efficiency of prepared polymer was strongly affected by healing temperature, crosslinking density and content of reversible tetra-sulfide groups. Investigation of self-healing hybrid sol-gel showed that regardless of mechanical properties' effect on the performance of healing properties, the content of reversible tetra sulfide groups was the main factor in the healing properties.