Synthesis and Characterization of Homopolymers and Copolymers Containing closo-[B12H12](2-) Boron Cage Derivatives

摘要

New [B12H12](2-) boron cage functionalized neutral and ionic methacrylate and styrene monomers (1, 2, 3) were synthesized and these monomers were used to prepare homopolymers (4, 5, 6) and copolymers with methylmethacrylate (MMA) (7, 8), 2-hydroxyethylmethacrylate (HEMA) (11, 12, 13, 17), 2-hydroxyethylacrylate (HEA) (14, 15, 18), acrylamide (AA) (16), and styrene (9, 10, 19) with different monomer ratios. Free-radical initiated bulk and solution polymerization methods were used to synthesize these polymers and they were characterized by H-1 NMR, B-11 NMR, and IR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and gel permeation chromatography (GPC). Generally, the polymers show broad H-1 NMR and B-11 NMR peaks compared to their respective monomers. The copolymers have high molecular weights with higher [B12H12](2-) boron cage mole ratios. All the polymers on which DSC experiments were conducted (4b, 5b, 6b, 7 8 9 10, 177, 18, and 19) are non-glassy amorphous solids, except styrene copolymers (9, 19) and homopolymer (6b) which show T-g values of 100, 117, and 162 degrees C, respectively. Copolymers 9 and 10 have higher thermal stability (320 degrees C) than polymers 5b, 4b, and 8, which are stable up to 244, 250, and 260 degrees C, respectively. The homopolymers retained more weight than the copolymers when they were heated to 400 degrees C.