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Your search keyword '"Luo, Jian-xin"' showing total 24 results
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24 results on '"Luo, Jian-xin"'

11. Thermal decomposition studies of highly alternating CO2- cyclohexene oxide copolymer

Author

Chen Li-ban, Luo Jian-xin, Zhang Min, Zou Zhiqiang, and Liu Bao-hua

Subjects
chemistry.chemical_compound, Materials science, Polymers and Plastics, chemistry, General Chemical Engineering, Kinetics, Thermal decomposition, Copolymer, Physical and Theoretical Chemistry, Photochemistry, Cyclohexene oxide
Abstract

Highly alternating CO2-cyclohexene oxide copolymer, namely poly(cyclohexene carbonate) (PCHC), considered potentially to be microelectronic sacrificial material, was successfully synthesized by copolymerization of cyclohexene oxide and CO2 in the presence of SalenAl(OiPr) catalyst. The obtained highly alternating PCHC copolymer were determined and proven to have superior thermal decomposition properties decomposing completely at 350 oC by thermogravimetric (TG) analysis under dynamic conditions. The thermal decomposition kinetics of the obtained PCHC was investigated by a different kinetic method using data from TG analysis. Based on the analytical, kinetic parameters were calculated and kinetic model of pyrolysis was proposed. TG-IR, Py-GC/MS, IR and 1H NMR techniques were applied to investigate the decomposition process. Based on Py-GC/MS and TG-IR techniques, carbon dioxide, 1,3-cyclohexadiene, cyclopentanecarboxaldehyde, cyclohexene oxide, cyclohexanone and trans-1,2- carbonyldioxycyclohexane were identified as thermal decomposition products of PCHC. The solid residues of the PCHC with 25% ether linkages decomposed at 200, 250, 300, 350 oC as determined by IR and 1H NMR. The results demonstrated that the carbonate content of the solid residues decreased gradually at elevated heat-temperatures and at 350 oC only few polyether linkages were observed.

Published
2009

24. Synthesis and Photophysics of Two Dipolar Copolymers Containing Hole-Transporting Unit and Alq3 Unit

Author

Luo, Jian Xin, Liang, Li Yan, and Lu, Man Geng

Abstract

Two novel copolymers combining the electron-transporting group (Alq3), hole-transporting group (carbazole and phenothiazine) and chromophore had been obtained. The copolymers were characterized by 1H NMR, IR and UV-vis absorption spectrum, and exhibited good solubility in a wide range of organic solvents such as toluene, THF, chloroform, DMF and DMSO. GPC shows moderate molecular masses of the copolymers around 15000 and a narrower weight distribution (PDI≈1.4). The DSC and TGA measurements indicated that the resulting copolymers have excellent thermal stability and higher glass transition temperatures than the commonly used light-emitting conjugated polymers. The PL properties of the copolymers were investigated in solution and in the solid state. Only the Alq3 emission (520 nm) was observed at high concentration (10 g/L) or in solid state. However, with the decrease in concentration of the copolymer solution, the characteristic emission of carbazole appears. This means the energy transfer taken place in higher concentration is more efficient than in lower concentration solution.

Published
2010
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