title: Synthesis and characterization of homopolymers and copolymers containing closo-[B(12)H(12)](2-) boron cage derivatives.
abstract: Chains of cages: Neutral/ionic [B(12)H(12)](2-) boron-cage-functionalized methacrylate and styrene homopolymers or copolymers (see picture) are non-crystalline solids, T(g) increases as the number of B(12) cages in the chain of polystyrene increases, and homopolymers retain more weight than the copolymers when heated to 400 degrees C.New [B(12)H(12)](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 (1)H NMR, (11)B NMR, and IR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and gel permeation chromatography (GPC). Generally, the polymers show broad (1)H NMR and (11)B NMR peaks compared to their respective monomers. The copolymers have high molecular weights with higher [B(12)H(12)](2-) boron cage mole ratios. All the polymers on which DSC experiments were conducted (4 b, 5 b, 6 b, 7, 8, 9, 10, 17, 18, and 19) are non-glassy amorphous solids, except styrene copolymers (9, 19) and homopolymer (6 b) 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 5 b, 4 b, 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.
authors.affiliation: The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Teshome B
authors.initials: TB
authors.lastname: Yisgedu
authors.forename: Xuenian
authors.initials: X
authors.lastname: Chen
authors.forename: Scott
authors.initials: S
authors.lastname: Schricker
authors.forename: Jon
authors.initials: J
authors.lastname: Parquette
authors.forename: Edward A
authors.initials: EA
authors.lastname: Meyers
authors.forename: Sheldon G
authors.initials: SG
authors.lastname: Shore
mesh_terms: D001896:Boron Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D006358:Hot Temperature; D009682:Magnetic Resonance Spectroscopy; D008689:Methacrylates / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*; D011137:Polystyrenes / Q000138:chemical synthesis / Q000737:chemistry; D013055:Spectrophotometry, Infrared
chemical_list: D001896:Boron Compounds; D008689:Methacrylates; D011108:Polymers; D011137:Polystyrenes