Effect of the conversion degree and multiple healing on the healing efficiency of a thermally reversible self‐healing polymer

• Published in: Polymers for advanced technologies Vol. 30; no. 11; pp. 2906 - 2917
• Main Authors: Shabani, Peyman, Shokrieh, Mahmood M., Zibaei, Iman
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 01.11.2019
• Subjects: Conversion; conversion degree; Diels‐Alder; Healing; healing kinetics; Modulus of rupture in bending; Polymers; Recovery; self‐healing; thermal remendability
• ISSN: 1042-7147; 1099-1581
• DOI: 10.1002/pat.4723

In this paper, the effect of the cross‐links' conversion degree on the healing efficiency of a thermally remendable polymer based on the Diels‐Alder (DA) reaction was studied quantitatively. By using the differential scanning calorimetry (DSC) results along with the Kissinger method, the conversion degree of the thermally reversible cross‐links was predicted as a function of time and temperature. For investigating the healing efficiencies at different conversion degrees, three‐point bending specimens were fabricated under certain curing conditions, which guaranteed the formation of both reversible and irreversible bonds. Afterward, specimens failed under three‐point bending test and healed up to certain conversion degrees. The results revealed on average 15%, 38%, and 83% recovery of flexural strength and 89%, 91%, and 93% recovery of flexural modulus at conversion degrees of 0.6, 0.8, and 1, respectively. Moreover, by repeating the damaging and healing procedure, it was shown that the synthesized polymer has the capability to be healed several times.