高纯度对苯二甲酸工艺技术的进展

综述了高纯度对苯二甲酸的生产方法、工艺特性、质量要求、开发研究动向及其发展趋势。     

采用模糊控制实现PTA半连续法聚酯切片生产的优化控制

运用系统工程的方法，在实现ＰＴＡ半连续法涤纶聚酯切片生产的过程控制时，采用可编程序控制器Ｆ１－６０ＭＲ和四回路调节器ＤＴＺＢ－４１１０Ｔ，采取精确ＰＩＤ与模糊控制相结合的控制规律，实现了关联系统的去耦和协调优化控制，达到了控制系统的总体目标。     

对苯二甲酸残渣生产对苯二甲酸二甲酯

利用回收的对苯二甲酸残渣生产对苯二甲酸二甲酯，讨论了影响酯化转化率的各种因素，得到了优化的酯化工艺条件。     

吡啶—2,6二甲酸合成工艺的研究

以２，６－壮甲基吡啶为原料，通过高锰酸钾氧化合成了哟啶－２，６－二甲酸。同时对影响产率的因素：高锰酸钾和水用量，反应时间、反应温度等作了探讨。通过正交试验，找到了最佳工艺条件，使产率由文献报导的６４％提高到８１％。     

生物基2,5-呋喃二甲酸聚酯的研究进展

2,5-呋喃二甲酸聚酯是以生物质平台化合物2,5-呋喃二甲酸为主要单体的生物基聚酯。该文主要介绍2,5-呋喃二甲酸聚酯的研究进展,对2,5-呋喃二甲酸聚酯的性能、合成方法、合成用催化剂及其共聚改性研究进行对比分析和讨论。2,5-呋喃二甲酸聚酯的玻璃化转变温度、热稳定性、杨氏模量和抗拉强度与对苯二甲酸聚酯的相应性能接近。同时,2,5-呋喃二甲酸聚酯及其共聚物对CO_2、O_2和H_2O的阻隔性能优于对苯二甲酸聚酯,在许多领域是聚酯PET等材料的潜在替代物,受到了业界的广泛重视。然而,较低的断裂伸长率是2,5-呋喃二甲酸聚酯应用的瓶颈问题。共聚改性是改善2,5-呋喃二甲酸聚酯力学性能的有效方法之一,已有的共聚改性单体在改善2,5-呋喃二甲酸聚酯的断裂伸长率时使共聚物的杨氏模量和玻璃化转变温度大幅下降,合成具有较高断裂伸长率、较高杨氏模量和较高玻璃化转变温度的2,5-呋喃二甲酸聚合物是国内外学者亟待解决的难题,也是2,5-呋喃二甲酸聚酯共聚改性领域的重要研究方向。     

合成吡咯-2,5-二甲酸及其酯的新方法

亚氨基二乙酸与二氯亚砜在过量的甲醇或乙醇溶剂中回流8h合成了亚氨基二乙酸二甲酯或亚氨基二乙酸二乙酯,然后与二水合三聚乙二醛在强碱甲醇钠或乙醇钠的作用下,合成了吡咯-2,5-二甲酸二甲酯或吡咯-2,5-二甲酸二乙酯,产率分别为67.6％和70.2％;吡咯-2,5-二甲酸二甲酯或吡咯-2,5-二甲酸二乙酯经碱性条件下水解、酸化合成了吡咯-2,5-二甲酸,总产率为62.4％～66.5％.     

对苯二甲酸工艺技术及生产

本文概述了对苯二甲酸生产方法,结合我国ＰＴＡ生产现状,对国内ＰＴＡ发展,提出了一些建议。     

用混合间,对苯二甲酸制备不饱和聚酯树脂

利用涤纶生产中的固体废弃物提取的间苯二甲酸和对苯二甲酸的混合二元酸，代替苯酐制备不饱和聚酯树脂。探讨了混合二元酸的提纯工艺，树脂的合成工艺，测试了此种树脂的性能。数据表明，用此种混合二元酸合成的树脂，成本低廉，耐腐蚀性能比１９１不饱和聚酯树脂有明显的提高。本方法也为合理利用工业固体废弃物找到一条新途径。     

运用系统工程理论实现PAT半连续法制聚酯的优化控制

运用系统工程的理论,在实现PTA半连续法聚酯切片生产的过程控制时,通盘筹划,合理安排,从整体性、综合性和最优性的基本观点出发,进行系统分析、系统设计和实施。通过采用带微处理器的过程控制仪表可编程控制器F1—60MR和四回路可编程调节器DTZB—4110T,采取精确PID与模糊控制相结合的控制规律,实现了关联系统的去耦和协调优化控制,最终达到了控制系统的总体目标,使切片质量上新台阶,改变了自产切片不能纺长丝的现状,每年为工厂节约成本达696万元。     

环己二甲酸/间苯型不饱合聚酯的合成及性能

以1,4-环己二甲酸(CHDA)和间苯二甲酸(PTA)作为不饱和酸组分,分别合成出环己二甲酸型(CH-DA-UP)和通用间苯二甲酸型(PTA-UP)不饱和聚酯(UP);分析比较了2种UP的合成工艺和合成物的FTIR谱图;考察了2种UP浇铸体的力学性能及其在Q-Sun Xenon Test Chamber老化箱中老化1 000 h的耐候性。结果表明:CHDA-UP的合成周期短(约为PTA-UP的0.65倍);CHDA-UP较PTA-UP更柔韧,综合性能好;虽然合成CHDA-UP所使用的是一种没有被完全氢化的CHDA,但是它的耐候性要比PTA-UP优越得多。     

Synthesis and characterization of transparent and high impact resistance polyurethane coatings based on polyester polyols and isocyanate trimers

A series of polyester polyols were synthesized by polycondensation reaction using adipic acid (AA), 1,4-cyclohexanedicarboxylic acid (1,4-CHDA), and 1,6-hexanediol (HDO), 1,4-cyclohexanedimethanol (1,4-CHDM) and trimethylol propane (TMP), in which the molar ratio of the reactants AA/1,4-CHDA was varied. These series of polyols were reacted with isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI), alone or in combination, to form polyurethane (PU) coatings.     

Influence of cycloaliphatic compounds on the properties of polyurethane coatings

A series of polyester polyol resin was synthesized by using 1,4-cyclohexanedimethanol (1,4-CHDM) and three different diacids: 1,3-cyclohexanedicarboxylic acid (1,3-CHDA), isophthalic acid (IPA) and adipic acid (AA). The solubility and viscosity of the polyester polyols were determined by using methyl ethyl ketone (MEK). All the polyester polyols were crosslinked with hexamethylene diisocyanate (HDI) isocyanurate to form polyurethane coating films. These films were evaluated for their mechanical and chemical resistance properties. Studies on the film characteristics revealed that the polyurethane films based on cycloaliphatic diacid generally showed comparatively better performance properties than the polyurethane film based on aromatic and linear aliphatic diacids in general.     

Cycloaliphatic polyester based high solids polyurethane coatings: I. The effect of difunctional alcohols

High-solids polyesters were synthesized with two cycloaliphatic diacids, 1,4- cyclohexanedicarboxylic acid (1,4-CHDA) and 1,3-cyclohexanedicarboxylic acid (1,3-CHDA); and with five diols, 1,4-cyclohexanedimethanol (CHDM), neopentyl glycol (NPG), hydroxypivalyl hydroxypivalate (HPHP), 2-butyl-2-ethyl-1, 3-propanediol (BEPD), and 1,6-hexanediol (HD). The viscosity of the polyesters was dependent on the structures of diols. The viscosity of polyesters is lower with the diol HD, intermediate with BEPD and HPHP, and higher with the diols CHDM and NPG. The polyesters were crosslinked with hexamethylene diisocyanate isocyanurate (HDI isocyanurate) affording polyurethane coatings. The mechanical properties, tensile properties, fracture toughness, and viscoelastic properties were investigated for the polyurethane films with five different diols. The cyclohexyl structure of the CHDM provides the polyurethane with rigidity which is manifested in high tensile modulus, hardness, and fracture toughness. In contrast, the linear diol, 1,6-hexanediol provides polyurethane with very high flexibility, but these coatings suffer with respect to low hardness and tensile modulus. Polymers and Coatings Department, Fargo, ND 58105. 3401 Grays Ferry Avenue, Philadelphia, PA 19146.     

Transparent polyester polyol-based polyurethane coatings: the effect of alcohols

A series of polyester polyols were synthesized using 1,6-hexanediol (HDO), 1,4-cyclohexanedimethanol (1,4-CHDM) and trimethylol propane (TMP), alone or in combination with 1,4-cyclohexanedicarboxylic acid and adipic acid. The polyester polyols were reacted with isocyanate trimers to form polyurethane (PU) coatings. Physical properties of the polyesters such as hydroxyl value, acid value, molecular weight, viscosity, and glass transition temperature (T _g) had been determined, and the IR spectroscopic analyses of polyesters/PU were reported. The properties (impact resistance, film flexibility, hardness, optical transmittance, chemical resistance, water absorption, thermostability, and phase separation) of the PU coatings so prepared were characterized. The viscosities of polyester polyols were dependent on the structure of the alcohols. Polyester polyol containing only linear aliphatic diol (HDO) was a transparent liquid at room temperature. The viscosity was increased by raising the molar ratio of 1,4-CHDM and/or TMP. All PU coatings had excellent flexibility, impact resistance, and hardness. The coatings derived from diol CHDM had the highest hardness, and the PU derived from diol HDO had the lowest hardness. The chemical resistance and water absorption improved with greater molar ratios of 1,4-CHDM or TMP. Results of differential scanning calorimetry and wide-angle X-ray diffraction indicated that there was no obvious crystallinity in the PU networks. Dynamic mechanical analysis (DMA) results revealed that both CHDM and TMP can increase the T _g of PU, and the crosslinking density improved with increased molar ratio of TMP. Atomic force microscope (AFM) and DMA analysis revealed that the PU coatings had no obvious microphase separation, which enabled them to have excellent properties, and the different composition in polyols did not have significant influence on transmittance in the visible region. Results of thermogravimetric measurements indicated that all the PU coatings had good thermal stability.     

Polyester hot-melt adhesives. I. Factors affecting adhesion to epoxy resin coatings

The peel strength and tensile shear strength of polyester hot-melt adhesives on metals coated with epoxy resins are affected by four characteristics of the polyester: (1) inherent viscosity, (2) glass transition temperature (T_g), (3) degree of crystallinity, and (4) melting point. The inherent viscosity affects the strength, toughness, and crystallinity of the adhesive. The T_g and degree of crystallinity affect the low-temperature adhesive properties; the peel strength is relatively low when the T_g is appreciably above the use temperature. The T_g, degree of crystallinity, and melting point affect the high-temperature adhesive properties. A hot-melt adhesive with high peel and tensile shear strengths from 0° to 120°C is the polyester of 1,4-butanediol and trans-1,4-cyclohexanedicarboxylic acid.     

对苯二甲酸和对羧基苯甲醛在醋酸水溶液中的溶解度

测定了420-505K温度范围内,对苯二甲酸和对羧基苯甲醛在醋酸水溶液中溶解度。在70%-100%醋酸水溶液中,70%醋酸使对苯二甲酸的溶解度对温度最敏感,随着醋酸浓度增加,对苯二甲酸的溶解度减少。当温度低于470K时,对苯二甲酸在水中的溶解性低于醋酸中的溶解度;温度高于470K时,对苯二甲酸在水中的溶解性对温度敏感明显提高。40%醋酸使对羧基苯甲醛的溶解度对温度最敏感, 随着醋酸浓度增加, 对羧基苯甲醛的溶解度增加。实验数据用修正的Apelblat方程进行了对苯二甲酸和对羧基苯甲醛在醋酸水溶液中溶解度关联,计算与实验值吻合良好。     

氧化镁非均相催化合成3-巯基丙酸

以1,4-二氧六环为溶剂,丙烯酸和硫化氢在自制氧化镁催化下合成3-巯基丙酸,产物经XRD、GC-MS和IR确证。合成3-巯基丙酸的适宜条件为:1,4-二氧六环为溶剂,反应温度80℃,H2S压力0.3 MPa,n(催化剂)∶n(丙烯酸)=0.2∶1,V(1,4-二氧六环)∶V(丙烯酸)=5∶0.2,反应时间5 h。在此条件下,丙烯酸转化率为98.8%,3-巯基丙酸选择性为36.2%,3-巯基丙酸收率为35.6%。     

混酸催化1,4-桉叶素异构化合成4-松油醇的研究

研究了在磷酸和乙酸混酸催化下,1,4-桉叶素异构化合成4-松油醇。考察了混酸催化剂种类、催化剂用量、反应温度、反应时间等因素对反应的影响。结果表明,最佳反应条件为:1,4-桉叶素10 mL,在12 mL磷酸与乙酸体积比为6∶1的混合酸催化剂中,反应温度60℃,反应时间8 h,1,4-桉叶素转化率可达74.66%,选择性为75.4%。精制后的4-松油醇质量分数在90%以上。     

生物可降解聚丁二酸己二酸丁二醇共聚酯的合成

通过控制1,4-丁二醇(B)与丁二酸(S)和己二酸(A)的投料比,经过酯化和缩聚制备了高摩尔质量的聚丁二酸己二酸丁二醇共聚酯.通过研究缩聚反应的时间、温度和催化剂用量对反应酯化率的影响,确定了制备聚丁二酸己二酸丁二醇共聚酯的最佳工艺.在最佳的反应条件下,反应酯化率最高为96.2%,PBSA(Mn=40 280g/mol,Mw/Mn=1.056 640).红外光谱的结果表明PBSA为一个高摩尔质量的聚酯.