Self-healing supramolecular elastomers based on the multi-hydrogen bonding of low-molecular polydimethylsiloxanes: Synthesis and characterization

Novel self-healing supramolecular elastomers based on polydimethylsiloxanes (SESi) were synthesized from a mixture of polydimethylsiloxanes derivers with single, di-, or tri-carboxylic acid groups (PDMS-COOHx, where x = 1, 2, and 3, respectively), diethylene triamine, and urea with a two-stage procedure. The reactions and the final products were tracked, characterized, and confirmed by Fourier transform infrared spectroscopy, 1H-NMR, differential scanning calorimetry, dynamic mechanical analysis, and gel permeation chromatography. Compared with a supramolecular rubber based on dimer acid (reported previously) with a similar synthesis procedure, the SESi showed a lower glass-transition temperature of about -113 degrees C for the softer chain of polydimethylsiloxane and showed real rubberlike elastic behavior and self-healing properties at room temperature or even lower temperatures. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013