对Pd/AC催化剂上对苯二甲酸(TA)加氢精制过程中的对羧基苯甲醛(4-CBA)加氢反应进行了研究。考察了氢分压、反应温度、催化剂颗粒大小对4-CBA消逝速率的影响,结果表明:在高于0.35 M Pa时,氢分压对4-CBA加氢反应速率的影响很小,而温度和...对Pd/AC催化剂上对苯二甲酸(TA)加氢精制过程中的对羧基苯甲醛(4-CBA)加氢反应进行了研究。考察了氢分压、反应温度、催化剂颗粒大小对4-CBA消逝速率的影响,结果表明:在高于0.35 M Pa时,氢分压对4-CBA加氢反应速率的影响很小,而温度和催化剂粒度大小对加氢反应的影响显著。同时,工业条件下的TA加氢精制过程存在着严重的内外扩散。采用幂函数动力学模型方程利用M atlab拟合得到了不同粒度催化剂上的表观动力学方程。展开更多
Micro-amount terephthalic acid and 4-carboxybenzaldehyde in p-toluic acids were determined by a reversed-phase ion suppression chromatography.The separation was carried out on a C18column（4.6mm i.d.×150mm）with ...Micro-amount terephthalic acid and 4-carboxybenzaldehyde in p-toluic acids were determined by a reversed-phase ion suppression chromatography.The separation was carried out on a C18column（4.6mm i.d.×150mm）with methanol-water（70∶30）as the mobile phase at a flow rate of 0.8ml/min and with H3PO4 as an inhibitor.The detection wavelength was 240 nm.The relative standard deviation of terephthalic acid and 4-carboxybenzaldehyde are less than 3% and 2%,respectively.The average recoveries were 102.9% and 103.2%,respectively.The detection limit were 0.25 ng and 0.45 ng,respectively.展开更多
A series of copolyesters poly(ethylene terephthalate p-oxybenzoate) (PETO) de-rived from terephthalic acid, ethylene glycol and 4, 4’ -oxybis (benzoic acid) were easily pre-pared by using DMT method and thermally inv...A series of copolyesters poly(ethylene terephthalate p-oxybenzoate) (PETO) de-rived from terephthalic acid, ethylene glycol and 4, 4’ -oxybis (benzoic acid) were easily pre-pared by using DMT method and thermally investigated. Introduction of 4, 4’ -oxydipheny-lene group into the main chain resulted in a lowering of Tm. a decrease of crystallization rate and an increase of thermal-oxidative stability of the copolyesters. By static elongation of PETO, transparent films with qualified electrical properties and mechanical properties were easily obtained with film forming rate 100%. In comparison with poly (ethylene terephthalate) (PET) film, PETO film had obviously low Tm. and low crystallization temper-ature. Due to the presence of stable aromatic ether structure, decrease in Tm. could not lead to any reduction in thermal-oxidative stability, on the contrary, slight increase was ob-served. PETO film could be used in making heat resistant thick film for channel insulators of electric motor.展开更多
文摘对Pd/AC催化剂上对苯二甲酸(TA)加氢精制过程中的对羧基苯甲醛(4-CBA)加氢反应进行了研究。考察了氢分压、反应温度、催化剂颗粒大小对4-CBA消逝速率的影响,结果表明:在高于0.35 M Pa时,氢分压对4-CBA加氢反应速率的影响很小,而温度和催化剂粒度大小对加氢反应的影响显著。同时,工业条件下的TA加氢精制过程存在着严重的内外扩散。采用幂函数动力学模型方程利用M atlab拟合得到了不同粒度催化剂上的表观动力学方程。
文摘Micro-amount terephthalic acid and 4-carboxybenzaldehyde in p-toluic acids were determined by a reversed-phase ion suppression chromatography.The separation was carried out on a C18column（4.6mm i.d.×150mm）with methanol-water（70∶30）as the mobile phase at a flow rate of 0.8ml/min and with H3PO4 as an inhibitor.The detection wavelength was 240 nm.The relative standard deviation of terephthalic acid and 4-carboxybenzaldehyde are less than 3% and 2%,respectively.The average recoveries were 102.9% and 103.2%,respectively.The detection limit were 0.25 ng and 0.45 ng,respectively.
文摘A series of copolyesters poly(ethylene terephthalate p-oxybenzoate) (PETO) de-rived from terephthalic acid, ethylene glycol and 4, 4’ -oxybis (benzoic acid) were easily pre-pared by using DMT method and thermally investigated. Introduction of 4, 4’ -oxydipheny-lene group into the main chain resulted in a lowering of Tm. a decrease of crystallization rate and an increase of thermal-oxidative stability of the copolyesters. By static elongation of PETO, transparent films with qualified electrical properties and mechanical properties were easily obtained with film forming rate 100%. In comparison with poly (ethylene terephthalate) (PET) film, PETO film had obviously low Tm. and low crystallization temper-ature. Due to the presence of stable aromatic ether structure, decrease in Tm. could not lead to any reduction in thermal-oxidative stability, on the contrary, slight increase was ob-served. PETO film could be used in making heat resistant thick film for channel insulators of electric motor.
