||This research includes two topics. The first topic is 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, 5triazine(VDAT) or vinylbenzyl -thymine (VBT). Using 1H nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), we investigated the thermal properties and hydrogen-bonding interactions within blends of the two copolymers poly(2-vinyl-4,6-diamino-1,3,5-triazine-co-methyl methacrylate) (PVD AT-co-PMMA) and poly(vinylbenzylthymine-co-methyl methacrylate) (PVBT-co-PMMA). A large positive deviation in the behavior of the glass transition temperature determined by 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 provided positive evidence for the presence of three hydrogen bonds between the diamino-1,3,5-triazine groups of PVDAT and thymine groups of PVBT.|
The second topic is synthesized a series of alkyne end-terminated poly(γ-Benzyl L-glutamate) (alkyne-PBLG), which was prepared by the ring-opening polymerization of the N-carboxyanhydride monomer of γ-Benzyl L-glutamate-carboxyanhydride. Then combination of the alkyne-PBLG with polyhedral oligomeric silsesquioxanes (POSS) with eight function groups are prepared through the click reation and formed a peptide-based block polymer with α-helice and β-sheet conformations. The thermal properties and structure of these polypeptides were characterized by using 1H NMR and FTIR. The FTIR, solid-state NMR and WXRD spectroscopic analyses provided evidence for the change of secondary structure between POSS and terminated peptide group, so that the conformation of β-sheets and α-helices would be influenced by the incorporation of POSS nanoparticle.