Complementary Multiple Hydrogen-Bonding Interactions Increase the Glass Transition Temperatures to PMMA Copolymer Mixtures

Abstract

We have prepared a series of poly(methyl methacrylate) (PMMA)-based copolymers through free radical copolymerizations of methyl methacrylate in the presence of the either 2-vinyl-4,6-diamino-1,3,5-triazine (VDAT) or vinylbenzylthymine (VBT). Using 1H nuclear magnetic resonance (NMR) spectroscopy, solid state 13C NMR spectroscopy, differential scanning calorimetry (DSC), one- and two-dimensional Fourier transform infrared (FTIR) spectroscopy, and viscosity measurements, we investigated the thermal properties of and hydrogen-bonding interactions within blends of the two copolymers poly(2-vinyl-4,6-diamino-1,3,5- triazine-co-methyl methacrylate) (PVDAT-co-PMMA) and poly(vinylbenzylthymine-co-methyl methacrylate) (PVBT-co-PMMA). A large positive deviation in the behavior of the glass transition temperature—determined using the Kwei equation and DSC analyses—indicated that strong multiple hydrogen-bonding interactions existed between the two copolymers. The FTIR and solid-state NMR spectroscopic analyses provi...