Studies on the Structure and Properties of Water-soluble Poly(aniline-co-N-acrylic acid aniline)

• Main Authors: Jing-Mei Shiu, 徐靜眉
• Other Authors: Chun-Lin Cheng
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/04617636125965307827

碩士 === 中原大學 === 化學工程研究所 === 89 === Abstract Polyaniline (PAn) is currently considered to have high potentiality toward practical applications due to its cheap, good environmental stability and protonation with a protonic acid. However, it is very difficult to be dissolved in common organic solvents owing to its inherent rigid backbone. Thus, the aim of this research is to study the mechanism of PAn by react with 2,2¢-azobis-isobutyronitrile (AIBN) and acrylic acid (AA) in dimethylsulfide (DMSO) solution, and to investigate structure of the polymers. After the modification of PAn, water soluble and doping occurs. The doping level of new water soluble polymers are lower than that of PAn doped with poly(acrylic acid) (PAA), since the former have the few imine structure so that the doptable positions are few than that of the latter. The tools used for the studied are gel permeation chromatograph (GPC), 13C-nuclear magnetic resonance spectroscopy (13C-NMR), ultraviolet-visible spectroscopy (UV-Vis), infrared spectrometer (IR), X-ray diffractometer (XRD), differential scanning calorimeter (DSC), dynamic mechanical analyzer (DMA), thermogravimetric analyzer (TGA), and conductivity measurements. In the true solution test, it was found that the new polymers (poly(aniline-co-N-acrylic acid-aniline)s, PAAns) could be dissolved in H2O. Results of GPC evidenced PAAns have only one molecular weight distribution. 13C-NMR Results indicated that the AA group is bonding with the nitrogen atom (N) of amine ring of PAn chain. For IR spectra, all the absorption bands at 1721 and 3488 cm-1 of C=O and N-H stretching vibration of PAA, respectively, and at 3220 and 1310 cm-1 of N-H and Caromatic-N stretching vibration of PAn, respectively, shifted toward low frequency. These results indicate the presence of hydrogen-bond interactions of PAn added with AA. For UV-vis results, the PAAns DMSO solutions, two absorption peaks exist at 358 nm (π-π* transition of the benzenoid ring) and 600 nm (excition absorption of the quinoid ring), and in the aqueous solutions, doping occurs. All of the decreasing of ratio of lmax,imine/lmax,amine in PAAns DMSO and aqueous solutions, and thin solid films. It is due to the thermal dissociation of DMSO into H· free radical, which will attack imine form of PAn to amine form, causing the decreasing of imine structure. XRD results indicate AA group help PAn chain to form a more regular phase resulting in the formation of a new phase at 2q = ~ 12°. The co-existence of two-phase strongly supports those hydrogen-bond interactions between the two components. For conductivity measurement as measured using the four-probe method, the decreasing of conductivity of PAn with the increasing of AA is due to the decreasing of imine in the reaction and the dropping of doping level.