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Acetoxybenzoic Acid (acetoxybenzoic + acid)
Selected AbstractsA novel thermotropic liquid crystalline copolyester containing phosphorus and aromatic ether moity toward high flame retardancy and low mesophase temperatureJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 5 2010Xiang-Cheng Bian Abstract A series of thermotropic liquid crystalline polyesters containing phosphorus and aromatic ether groups (TLCP-AEs) were synthesized from p -acetoxybenzoic acid (p -ABA), terephthalic acid (TPA), 4,4,-oxybis(benzoic acid) (OBBA), and acetylated 2-(6-oxid-6H-dibenz(c,e) (1,2) oxaphosphorin 6-yl) 1,4-benzenediol (DOPO-AHQ). The chemical structure and the properties of TLCP-AEs were characterized by Fourier-transform spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), thermogravimetry analysis (TGA), scanning electronic microscopy (SEM), polarizing optical microscopy (POM), limiting oxygen index, and UL-94 tests, respectively. The results showed that TLCP-AEs had low and broad mesophase temperatures (230,400 °C). TLCP-AEs also showed excellent thermal stability; their 5%-weight-loss temperatures were above 440 °C and the char yields at 700 °C were higher than 45 wt %. All TLCP-AE polyesters exhibited high flame retardancy with a LOI value of higher than 70 and UL-94 V-0 rating. The SEM observation revealed that TLCP-AEs had good fibrillation ability. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1182,1189, 2010 [source] A phosphorus-containing thermotropic liquid crystalline copolyester with low mesophase temperature and high flame retardanceJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 17 2008Cheng-Shou Zhao Abstract A novel phosphorus-containing thermotropic liquid crystalline copolyester with flexible spacers (P-TLCP-FS) was synthesized by melt transesterification from p -acetoxybenzoic acid (p -ABA), terephthalic acid (TPA), ethylene glycol, and acetylated 2-(6-oxid-6H-dibenz(c,e) (1,2) oxaphosphorin 6-yl) 1,4-benzenediol (AODOPB). The chemical structure and properties of the obtained P-TLCP-FS were characterized by Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (1H-NMR), inherent viscosity measurements, differential scanning calorimetry (DSC), thermogravimetry (TGA), polarizing light microscopy (PLM), and X-ray diffraction (XRD) analysis. P-TLCP-FS had inherent viscosities of 0.92,1.12 dL/g and exhibited low and wide mesophase temperatures, ranging from 185 to 330 °C, which can match with the processing temperatures of most conventional polymers and high flame retardancy with a limiting oxygen index value of 70% and UL-94 V-0 rating. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5752,5759, 2008 [source] Selective preparation of poly(p -oxybenzoyl) by using fractional polycondensationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2006Kunio Kimura Abstract Selective preparation of poly(p -oxybenzoyl) (POB) in the copolymerization system of p -acetoxybenzoic acid (p -ABA) and m -acetoxybenzoic acid (m -ABA) was examined by using reaction-induced crystallization of oligomers. Polymer crystals mainly composed of p -oxybenzoyl moiety were precipitated when the content of m -ABA in the feed was 30 mol %. The formation of the polymer crystals was attributed to both the reactivity of monomer and the phase-separation behavior of oligomer. Reactivity of p -ABA was twice higher than that of m -ABA, and thereby, the homo-oligomers of p -oxybenzoyl moiety were more rapidly formed in solution than do co-oligomers at the early stage in polymerization. They were selectively precipitated by crystallization to form crystals because of low miscibility. Co-oligomers containing m -oxybenzoyl moiety were also formed in solution, but they were unable to be phase-separated because of higher miscibility. Further polycondensation occurred between oligomers in the precipitated crystals, leading to the formation of POB. This polymerization proceeded with selecting certain monomers by crystallization and afforded a new methodology for fractional polycondensation. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2732,2743, 2006 [source] Morphology of poly(p -oxybenzoyl) prepared in perfluoropolyetherPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 1 2005Kunio Kimura Abstract Solvent effect on the morphology of poly(p -oxybenzoyl) (POB) prepared by the reaction-induced phase separation of oligomers was examined by the polymerization of p -acetoxybenzoic acid in perfluoropolyether AflunoxTM (AFL2507 and AFL606). Polymerization was carried out at 320°C for 6,hr. POB microspheres were formed in AFL2507 by the liquid,liquid phase separation of oligomers due to the low miscibility of oligomers in AFL2507. The molecular weight of the solvent influenced the morphology, and the polymerization in AFL606 of which the molecular weight was lower than AFL2507 yielded whiskers formed by crystallization of oligomers induced by the increase in miscibility compared with that in AFL2507. The solvent structure and its molecular weight influenced the miscibility of oligomers and ultimately controlled the morphology from whisker to microsphere. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||