The thermal self‐healing properties of phenolic polyurethane derived from polyphenols with different substituent groups

ABSTRACT Phenolic hydroxyl gave thermal self‐healing ability to phenolic polyurethanes in our previous study. To explore, the feasibility of preparing self‐healing polyurethanes through polyphenols with different substituents. Urushiol, propyl gallate, catechol, and tert‐butylhydroquinone were chosen for preparation of four phenolic polyurethanes, and the different factors at the structures of these polyphenols worked together led the different properties and self‐healing ability. The peak temperatures of these four polyurethanes were determined by DSC in the following order: PTHFTDI‐Urushiol < PTHFTDI‐Catechol < PTHFTDI‐Propyl gallate < PTHFTDI‐Tert‐butylhydroquinone. Variable‐temperature FT‐IR spectra displayed that PTHFTDI‐Propyl gallate with electron‐withdrawing substituent exhibited the lowest decomposition and healing temperatures. Meanwhile, based on TGA analysis, lower decomposition temperature suggested lower thermostability; and PTHFTDI‐Urushiol with electron‐donating substituent exhibited the best thermostability. At the same temperature, the healing abilities of the three polyurethanes were ranked as follows: PTHFTDI‐Catechol < PTHFTDI‐Urushiol < PTHFTDI‐Propyl gallate. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47039.