1,3-丙二醇钛催化合成PTT的工艺研究

以自制的1,3-丙二醇钛为催化剂,采用对苯二甲酸(PTA)和1,3-丙二醇(PDO)为原料,通过直接酯化法制得聚对苯二甲酸丙二醇酯(PTT);研究了催化剂用量、反应物配比、酯化和缩聚温度、缩聚时间等对反应结果的影响.结果表明:以1,3-丙二醇钛为催化剂制备PTT是可行的;在酯化反应温度为230～235℃,PDO/PTA...     

牛物法PDO合成PTT结构与性能的研究

采用生物法1，3-丙二醇（PDO）直接酯化缩聚合成聚对苯二甲酸丙二醇酯（PTT），通过IR、^1H NMR、DSC和TG方法对其进行了表征，并与化学法PDO合成的PTT进行比较。结果表明，生物法PDO合成的产物是PTT；生物法PDO合成的肿比同一纯度的化学法PDO合成的肿色泽好、粘度大、摩尔质量高，且随PDO纯度提高，肿粘度、摩尔质量增大；生物法PDO合成的肿熔点与化学法PDO合成的肿相差不大，熔融峰比化学法PDO合成的肿尖锐，熔融热大，结晶度高；不同PDO合成的肿树脂热失重相差不大，表明PDO不同对肿热分解行为影响不大。     

直接酯化法合成PTT的工艺探讨

研究了采用直接酯化法合成聚对苯二甲酸丙二醇酯(PTT)的催化剂种类、催化剂浓度、反应物料的物质的量比以及升温速率对反应的影响。实验证明,以硫酸钛水解物为酯化催化剂,三氧化二锑作为缩聚催化剂合成PTT是可行的。     

PTT纤维的发展和应用

综述了新型纺织材料－－聚对苯二甲酸丙二醇酯（PTT）的聚合、性质、纺丝工艺及其应用。并分析了PTT的研究和发展前景。     

PTT聚酯纤维的应用及市场前景

PTT(聚对苯二甲酸-1，3-丙二醇酯)又名PPT，PTMT，是一种新型聚酯材料，最近几年中已逐渐实现了工业化生产。传统的1，3-丙二醇合成路线是以丙烯醛为原料，通过水合作用制取，近年来已被环氧乙烷原料取代。另一种合成方法以丙三醇为原料通过发酵作用来制备1，3-丙二醇(PDO)。因     

草酸亚锡催化合成双季戊四醇六正戊酸酯

以草酸亚锡为催化剂,进行双季戊四醇和正戊酸的酯化反应,合成了双季戊四醇六正戊酸酯,考察了催化剂用量、醇酸配比、反应温度、反应时间等因素对酯化率的影响。确定了优化合成条件:n(正戊酸)∶n(双季戊四醇)=6.5∶1.0,催化剂用量为反应物总质量的0.05%, 210℃酯化反应7 h,酯化率超过99%,用红外光谱、气相色谱和核磁对反应产物进行了表征。     

PTT原料1，3-丙二醇的生产技术

1，3-丙二醇(PDO)是生产聚对苯二甲酸丙二醇酯(PTT)的重要原料，因制备PDO的费用较高，曾影响了PTT的发展。     

均匀试验设计法对PTT合成工艺的优化研究

使用钛酸四丁酯作为聚对苯二甲酸丙二醇酯(PTT)合成催化剂,以对苯二甲酸(TPA)和1,3-丙二醇(PDO)为原料,通过直接酯化法合成得到纤维级PTT;运用均匀实验设计方法,对PTT合成的工艺条件进行了优化,得到了各个工艺条件与产品特性黏数的作用关系。结果表明:PTT合成优化工艺条件为PDO和TPA的摩尔比1.345 9,催化剂与TPA的摩尔比9.0×10-4,不加抗氧剂,反应温度262℃,拟合方程预测产品特性黏数最优结果为1.049 1 dL/g,实验验证结果为1.031 3 dL/g;拟合方程的预测性较好。     

草酸亚锡催化酯交换合成水杨酸异辛酯

以草酸亚锡作为催化剂,水杨酸甲酯和异辛醇为原料,用酯交换的方法合成了防晒剂水杨酸异辛酯,并对产品进行指标检测。考察了影响水杨酸甲酯转化率的5个合成条件,再通过正交试验L9(34)得到较佳合成条件为:催化剂草酸亚锡用量(相对于原料的总投入质量)为0.4%,m(酯)∶m(醇)=1∶1.3,终点反应温度为190℃,总反应时间为7 h。验证实验表明该条件下水杨酸甲酯平均转化率为99.2%且具有重复性。所制备的水杨酸异辛酯产品的质量指标接近美国国际特品公司(ISP)的ESCALOL587。     

聚对苯二甲酸丙二酯研究进展

综述了聚对苯二甲酸丙二酯(PTT)的合成方法及原料生产方法,介绍了PTT的结构与物理机械性能、结晶性能、热性能和流变性能,认为发展PTT应优先发展环氧乙烷法生产1,3-丙二醇。     

PTT树脂及其开发进展

综述了聚对苯二甲酸丙二酯(PTT)树脂的合成工艺、性能及应用,并介绍了近年来PTT树脂研究开发的新进展.     

Depolymerization of poly(trimethylene terephthalate) in supercritical methanol

The depolymerization of poly(trimethylene terephthalate) (PTT) in supercritical methanol was carried out with a batch‐type autoclave reactor at temperatures ranging from 280 to 340°C, at pressures ranging from 2.0 to 14.0 MPa, and for reaction time of up to 60 min. PTT quantitatively decomposed into dimethyl terephthalate (DMT) and 1,3‐propaniol (PDO) under the designed conditions. The yields of DMT and PDO greatly increased as the temperature rose. The yields of the monomers markedly increased as the pressure increased to 10.0 MPa, and they leveled off at higher pressures. The final yield of DMT at 320°C and 10.0 MPa reached 98.2%, which was much closer to the extent of the complete reaction. A kinetic model was used to describe the depolymerization reaction, and it fit the experimental data well. The dependence of the forward rate constant on the reaction temperature was correlated with an Arrhenius plot, which gave an activation energy of 56.8 kJ/mol. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2363–2368, 2004     

Melting behavior of poly(trimethylene terephthalate)

In this study, the melting behavior of isothermally crystallized polytri‐ methylene terephthalate (PTT) was investigated. Multiple melting behaviors in DSC heating trace were found because two populations of lamellar stacks were formed during primary crystallization and the recrystallization at heating process, respectively. This fact could be also confirmed from the result of optical microscopy observation. The Hoffman–Weeks equation was applied to obtain equilibrium melting temperature (T). The T value of PTT is about 525 K, which is 10 K higher than that reported. Combining the enthalpy of fusion from the DSC result and the degree of crystallinity from WAXD result, the value of the equilibrium‐melting enthalpy ΔH was deduced to be approximately 28.8 kJ mol^?1. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2426–2433, 2002     

Alkaline depolymerization of poly(trimethylene terephthalate)

The purpose of this study was to investigate the effects of reaction media, composition, and temperature on the rate of the alkaline depolymerization of poly(trimethylene terephthalate) (PTT). The alkaline depolymerization of PTT was carried out at 160–190°C in ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), ethylene glycol monobutyl ether (EGMBE), diethylene glycol monoethyl ether (DEGMEE), and a mixture of these solvents. During the reaction, PTT was quantitatively converted to disodium terephthalate and 1,3-propanediol. The alkaline depolymerization reaction rate constants were calculated based on the concentration of sodium carboxylate, which was equivalent to the molar amount of sodium hydroxide. The depolymerization rate of PTT was increased by increasing the reaction temperature and by adding ethereal solvents. Moreover, the depolymerization rate was significantly accelerated in the order of EG < DEG < TEG < EGMBE < DEGMEE. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 99–107, 2001     

Study on the macrokinetics of poly(trimethylene terephthalate) polycondensation reaction

The macrokinetics of poly(trimethylene terephthalate) (PTT) polycondensation reaction during the high‐vacuum process was studied. The results showed that PTT polycondensation reaction may be considered as a second‐order reaction and thermal degradation is negligible in mathematical handling. The intrinsic viscosity versus time undergoes two different processes according to temperature. The apparent reaction rate constants and apparent activation energy of PTT polycondensation reaction are smaller than those of PET. Under efficient stirring, PTT polycondensation reaction is still reaction‐controlled and the role of devolatilization could be neglected even during the high‐vacuum process. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1765–1770, 2004     

Isothermal gravimetric analysis of poly(trimethylene terephthalate)

Poly(trimethylene terephthalate) was investigated by isothermal thermogravimetry in nitrogen at six temperatures, including 304, 309, 314, 319, 324, and 336°C. The isothermal data have been analyzed using both a peak maximum technique and an iso‐conversional procedure. Both techniques gave apparent activation energies of 201 and 192 kJ mol^?1, respectively, for the isothermal degradation of poly(trimethylene terephthalate) in nitrogen. The decomposition reaction order is calculated to be 1.0. The natural logarithms of the frequency factor based on the peak maximum and the iso‐conversional techniques are 36 and 34 min^?1, respectively, for poly(trimethylene terephthalate) decomposed isothermally in nitrogen. These isothermal kinetic parameters are in good agreement with those derived by the Kissinger technique on the basis of the dynamic thermogravimetric data reported elsewhere (209 kJ mol^?1, 1.0 and 37 min^?1). The isothermal decomposition of poly(trimethylene terephthalate) in nitrogen undergoes two processes, a relative fast degradation process in the initial period and a subsequent one with a slower weight‐loss rate. The former process may be due to the removal of ester groups, trimethylene groups, and aromatic hydrogen atoms from the chain of poly(trimethylene terethphalate). The latter one may be ascribed to the further pyrolysis of the carbonaceous char. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1600–1608, 2002; DOI 10.1002/app.10476     

High birefringence of poly(trimethylene terephthalate) spherulite

Poly(trimethylene terephthalate) (PTT) spherulite shows interference color under polarized light microscope without a sensitive tint plate. The fact indicates that the retardation of PTT spherulite is high, while it was reported that the birefringence in PTT fiber is low. In this study, the reason why the high birefringence is observed in PTT spherulite was discussed. By small area X-ray diffraction measurement, it was confirmed that a-axis of unit cell of PTT crystal was parallel to the radial direction of the spherulite. Based on the result, we calculated the refractive indices of parallel to a-axis and the other orthogonal directions. It was clarified that the refractive index of a-axis is much lower than the others and the intrinsic birefringence for a-axis orientation is high. It is the reason why the PTT spherulite shows high and negative birefringence.     

Thermal decomposition kinetics of thermotropic poly(oxybenzoate‐co‐trimethylene terephthalate)

A new kind of thermotropic liquid crystalline, poly(oxybenzoate‐co‐trimethylene terephthalate), was prepared from p‐hydroxybenzoic acid (B) and poly(trimethylene terephthalate) (PTT or T) by melting polycondensation. The monomer ratio of B to T is 60:40. The dynamic thermogravimetric kinetics of the copolymer B/T (60:40) and PTT in nitrogen were analyzed by four single heating rate techniques and two multiple heating rate techniques. The effects of the heating rate and the calculating technique on the thermostable and degradation kinetic parameters of the B/T copolymer and PTT are systematically discussed. The four single heating rate techniques used in this work include Friedman, Freeman‐Carroll, Chang, and the second Kissinger techniques, whereas the two multiple heating rate techniques are the first Kissinger and Flynn‐Wall techniques. Additionally, the isothermal thermogravimetric kinetics of B/T (60:40) in nitrogen were investigated by the Flynn technique. The activation energy, the order, and the frequency factor of the degradation reaction for B/T (60:40) copolymer are determined to be 185 kJ/mol, 1.8, and 7.14 × 10¹³ min⁻¹, respectively. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2025–2036, 2000