Polymers (Mar 2019)

Self-Healing Hydrogels with both LCST and UCST through Cross-Linking Induced Thermo-Response

  • Haifeng Zhao,
  • Heng An,
  • Baozhong Xi,
  • Yan Yang,
  • Jianglei Qin,
  • Yong Wang,
  • Yingna He,
  • Xinguo Wang

DOI
https://doi.org/10.3390/polym11030490
Journal volume & issue
Vol. 11, no. 3
p. 490

Abstract

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Self-healing hydrogels have drawngreat attention in the past decade since the self-healing property is one of the characteristics of living creatures. In this study, poly(acrylamide-stat-diacetone acrylamide) P(AM-stat-DAA) with a pendant ketone group was synthesized from easy accessible monomers, and thermo-responsive self-healing hydrogels were prepared through a series of diacylhydrazide compounds cross-linking without any additional stimulus. Although the copolymers do not show thermo-response, the hydrogels became thermo-responsive andboth the lower critical solution temperature (LCST) and upper critical solution temperature (UCST) varied with the composition of the copolymer and structure of cross-linkers. With a dynamic covalent bond connection, the hydrogel showed gel-sol-gel transition triggered by acidity, redox, and ketone to acylhydrazide group ratios. This is another interesting cross-linking induced thermo-responsive (CIT) hydrogel with different properties compared to PNIPAM-based thermo-responsive hydrogels. The self-healing hydrogel with CIT properties could have great potential for application in areas related to bioscience, life simulation, and temperature switching.

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