A novel poly(methyl methacrylate-co-polyhedral oligomeric silsesquioxane) hybrid nanocomposite was synthesized by free radical polymerization and characterized by 1H NMR, 29Si NMR, and TGA technologies. Compared wit...A novel poly(methyl methacrylate-co-polyhedral oligomeric silsesquioxane) hybrid nanocomposite was synthesized by free radical polymerization and characterized by 1H NMR, 29Si NMR, and TGA technologies. Compared with PMMA homopolymer, the nanocomposite has better thermal stability.展开更多
While WC_16-Ph_4Sn is a poor catalyst for the polymerization of l-phenyl-butyne (PB) at room temperature, it effectively polymerizes PB in the presence of C_(60), giving high molecular weight polymers in high yields. ...While WC_16-Ph_4Sn is a poor catalyst for the polymerization of l-phenyl-butyne (PB) at room temperature, it effectively polymerizes PB in the presence of C_(60), giving high molecular weight polymers in high yields. The polymer is soluble in THF and chloroform and spectroscopic analysis reveals that Coo has copolymerized with PB. Thus, C_(60) plays dual roles of comonomer and cocatalyst in the acetylene polymerization. The copolymers strongly attenuate 532-nm laser pulses, whose limiting performance is superior to that of parent C_(60)展开更多
A novel bifunctional comonomer 3-ammoniumcarboxylate-butenoic acid-methyl ester (ACBM) was synthesized tor preparing poly[acrylonitrile-co-(3-ammoniumcarboxylate-butenoic acid-methyl ester)] [P(AN-co-ACBM)] copo...A novel bifunctional comonomer 3-ammoniumcarboxylate-butenoic acid-methyl ester (ACBM) was synthesized tor preparing poly[acrylonitrile-co-(3-ammoniumcarboxylate-butenoic acid-methyl ester)] [P(AN-co-ACBM)] copolymer as a carbon fiber precursor. Differential scanning calorimetry results show that the P(AN-co-ACBM) exhibits a significantly improved stabilization performance compared with polyacrylonitrile (PAN), such as lower cyclization temperature and smaller rate of heat release, which is mainly attributed to the initiation of ACBM through an ionic cyclization mechanism. Simultaneously, the rheological analysis shows that P(AN-co-ACBM) possesses better spinnabilitv than PAN.展开更多
A novel octazido substituted nanobuilding precursor, octakis[dimethy(p-azidomethylene)siloxyl]octasilsesquioxane (ODA), was prepared by the conventional diazo-transfer reaction of octalds[dimethy(p-chloromethylen...A novel octazido substituted nanobuilding precursor, octakis[dimethy(p-azidomethylene)siloxyl]octasilsesquioxane (ODA), was prepared by the conventional diazo-transfer reaction of octalds[dimethy(p-chloromethylene)silyl]octasilsesquioxane (ODC) with NAN3, and its structure was characterized by FT-IR, 1H, a3C, 29Si NMR and MALDI-TOF MS, respectively. The structural rearrangement of POSS core in the synthesis strategy of ODA developed in this work was effectively prohibited in comparison with traditionary azidization process. The resultant ODA was not only soluble in common solvents such as CHC13, THF, toluene, DMF and DMSO, but also could effectively serve as a versatile nanobuilding precursor for the architecture of well-defined organic- inorganic hybrids via click chemistry.展开更多
A novel functional polyacetylene containing fluorene group as a pendant,poly(2-(p-methylstyrene)-7-acetylene-9,9-dioctyl-fluorene), was synthesized in moderate yield by[Rh(nbd)Cl]_2-Et_3N catalyst.The structures...A novel functional polyacetylene containing fluorene group as a pendant,poly(2-(p-methylstyrene)-7-acetylene-9,9-dioctyl-fluorene), was synthesized in moderate yield by[Rh(nbd)Cl]_2-Et_3N catalyst.The structures and properties of monomer and polymer were characterized and evaluated with FTIR,NMR,UV-vis,GPC and Z-scan,respectively.The results show that the incorporation of fluorene into polyacetylene has endowed the resultant polymer with well optical limiting properties for laser at wavelength 780 nm based on two-photon absorption mechanism.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.50472038 and 90606011)Program for New Century Excellent Talents in University(NCET-04-0588)the Excellent Youth Fund of Anhui Province(No.04044060).
文摘A novel poly(methyl methacrylate-co-polyhedral oligomeric silsesquioxane) hybrid nanocomposite was synthesized by free radical polymerization and characterized by 1H NMR, 29Si NMR, and TGA technologies. Compared with PMMA homopolymer, the nanocomposite has better thermal stability.
文摘While WC_16-Ph_4Sn is a poor catalyst for the polymerization of l-phenyl-butyne (PB) at room temperature, it effectively polymerizes PB in the presence of C_(60), giving high molecular weight polymers in high yields. The polymer is soluble in THF and chloroform and spectroscopic analysis reveals that Coo has copolymerized with PB. Thus, C_(60) plays dual roles of comonomer and cocatalyst in the acetylene polymerization. The copolymers strongly attenuate 532-nm laser pulses, whose limiting performance is superior to that of parent C_(60)
基金supported by the National Natural Science Foundation of China(Nos.51073031, 20971021 and 20974018)Doctoral Dissertation Innovation Project(No.BC201004)
文摘A novel bifunctional comonomer 3-ammoniumcarboxylate-butenoic acid-methyl ester (ACBM) was synthesized tor preparing poly[acrylonitrile-co-(3-ammoniumcarboxylate-butenoic acid-methyl ester)] [P(AN-co-ACBM)] copolymer as a carbon fiber precursor. Differential scanning calorimetry results show that the P(AN-co-ACBM) exhibits a significantly improved stabilization performance compared with polyacrylonitrile (PAN), such as lower cyclization temperature and smaller rate of heat release, which is mainly attributed to the initiation of ACBM through an ionic cyclization mechanism. Simultaneously, the rheological analysis shows that P(AN-co-ACBM) possesses better spinnabilitv than PAN.
基金supported by the National Natural Science Foundation of China(Nos.51073031, 51003013,20971021 and 20974018)Doctoral Dissertation Innovation Project(No.BC200901)
文摘A novel octazido substituted nanobuilding precursor, octakis[dimethy(p-azidomethylene)siloxyl]octasilsesquioxane (ODA), was prepared by the conventional diazo-transfer reaction of octalds[dimethy(p-chloromethylene)silyl]octasilsesquioxane (ODC) with NAN3, and its structure was characterized by FT-IR, 1H, a3C, 29Si NMR and MALDI-TOF MS, respectively. The structural rearrangement of POSS core in the synthesis strategy of ODA developed in this work was effectively prohibited in comparison with traditionary azidization process. The resultant ODA was not only soluble in common solvents such as CHC13, THF, toluene, DMF and DMSO, but also could effectively serve as a versatile nanobuilding precursor for the architecture of well-defined organic- inorganic hybrids via click chemistry.
基金financially supported by the National Natural Science Fund of China(Nos.20971021,51073031 and 20974018)the National Oversea Scholar Cooperation Research Found of China(No.50928301)
文摘A novel functional polyacetylene containing fluorene group as a pendant,poly(2-(p-methylstyrene)-7-acetylene-9,9-dioctyl-fluorene), was synthesized in moderate yield by[Rh(nbd)Cl]_2-Et_3N catalyst.The structures and properties of monomer and polymer were characterized and evaluated with FTIR,NMR,UV-vis,GPC and Z-scan,respectively.The results show that the incorporation of fluorene into polyacetylene has endowed the resultant polymer with well optical limiting properties for laser at wavelength 780 nm based on two-photon absorption mechanism.