高分子量PET／60PHB热致性液晶共聚酯的结构与性能

研究了固相缩聚过程中PET/60PHB共聚酯结构性能的变化。随着反应的进行,分子量增大,分子量分布宽度指数变小;玻璃化温度略增,熔融温度增加幅度较大;热稳定性明显提高。预聚体中主要存在PET的低共熔物或部分同二质晶,固相缩聚反应使PET结晶消失,PHB结晶形成并完善。固相缩聚大大改善了共聚酯的可纺性,用[η]为0.95dL/g的共聚酯制得断裂强度达到高强范围(1GPa)的初生纤维。     

连续式固相缩聚生产高粘度聚酯切片的技术与工艺

针对引进美国Ｂｅｐｅｘ公司制造的生产涤纶工业丝用高粘度聚酯切片的连续式固相缩聚系统，对切片的原料路线、预结晶后的结晶度、干燥后的含水、预热后的结晶度、净化器中停留时间、反应温度、反应时间等工艺控制要点及影响因素作了详细探讨。     

杜邦聚酯制造新技术

介绍了杜邦公司近年来开发的聚酯制造新技术。①常压缩聚，通过向体系中通入惰性气体，以降低缩聚副产物ＥＧ的分压来实现；②悬浮态缩聚，此为非熔态缩聚，是采用溶剂—非溶剂体系作为反应介质。此技术对制造高粘度聚酯有明显优越性；③管式预缩，此技术还可与废聚酯再利用、齐聚物固相缩聚相结合。这些新技术可提高生产率，减少设备投资，降低原材料消耗和能耗，降低产品成本。     

聚酯连续式与间歇式固相缩聚的比较

生产涤纶工业丝需采用高粘度聚酯,其生产方法有熔体增粘、连续式固相缩聚、间歇式固相缩聚,这三种方法国外生产厂家都在使用。本文根据我厂工业丝的生产经验,结合国外公司技术交流及出国考察等资料,对聚酯连续式和间歇式固相缩聚进行了多方面的详细比较。     

全芳液晶聚酯固相缩聚及其性能的研究

研究了用固相缩聚方法提高全芳液晶聚酯的分子量。以２，６－萘二甲酸，对／间羟基苯甲酸、双酚类单体为原料，经熔融酯交换合成低聚物，再以固相反应制备共聚酯。通过对共聚酯熔融指数的变化，探讨固相缩聚中反应时间和反应温度的效应，共聚酯分子结构和聚集态结构与固相缩聚反应速率的关系；并通过Ｘ－射线衍射分析，考察固相缩聚对聚酯结晶性的影响。得出全芳聚酯固缩聚过程是一个由化学反应为主要控制，继而转化到物理扩散为主要     

固相缩聚PET的结晶性能研究

本文选用几种固相缩聚制备的高粘度聚酯,研究了它们的结晶速度、结晶度,得到了较好的规律,并与原料的品质、固相缩聚工艺等结合起来进行了讨论.     

粉末PET固相缩聚的研究

系统地研究了粉末聚酯(PET)固相缩聚,得到了有效的干燥结晶条件:140℃干燥120 min,180℃再结晶45 min,切片含水率低于30μg／g;研究了反应温度,粉末粒径和N2流量对PET固相缩聚的影响,分析粉末固相缩聚存在N2流量阈值的机理。结果表明:反应温度越高,颗粒越小,固相缩聚反应速度越快;粉末 PET预聚体在一定温度下固相缩聚,存在N2流量阈值。在此流量下,达到该温度下的该粒径粉末的最大界面扩散速率和固相缩聚的最大反应速度。相同反应温度下,粉末粒径越小,阈值N2流量越大。     

聚对苯二甲酸乙二酯(PET)固相缩聚动力学研究

本文以小型真空转鼓为反应装置,研究了PET的固相缩聚动力学,采用的PET预聚体是直接酯化工艺生产的未消光切片和酯交换工艺生产的不同厚度的薄膜。实验结果指出:在本实验条件下,PET预聚体的链增长速度在215℃处有一转折。动力学数据处理的结果表明:在固相缩聚期间PET的链增长按二级反应进行,而且与文献报道的动力学结果基本一致。对不同厚度的薄膜进行固相缩聚动力学研究,并用拉格朗日插值法外推到厚度为零,得到了消除样品层厚度影响的化学反应的表观动力学。实验结果还发现,左PET预聚体的固相缩聚期间,羧端基含量有所降低,醚键含量基本不变,并从反应机理上给予了说明。     

FDY高强聚酯长丝生产技术研究

较系统地研究了 PET 切片的固相缩聚工艺、高粘度切片的熔融纺丝以及拉伸卷绕工艺.研究结果表明:采用国内 TPA 法生产的 PET 大有光切片,选择合理的固相缩聚工艺,可满足高强聚酯长丝的生产需要;在切片固相缩聚过程中,对粘度增长贡献的大小依次为:真空度>温度>时间;无油丝粘度在0.92dL/g 左右,聚酯纤维可获得优良的物理机械性能和良好的热稳定性.     

粉状聚酯固相缩聚反应动力学与降解行为的研究

与固相缩聚工业生产用常规粒径聚酯相比,粉状聚酯的传质和反应均可得到增强.实验研究了不同粒径粉状聚酯(0.2～0.8 mm)在氮气氛围中的固相增黏规律,并采用模型方法对缩聚反应与降解行为进行了分析.结果表明粉状聚酯的固相缩聚反应是缩聚与降解的竞争过程,反应初期缩聚反应占主导地位,特性黏度随反应不断增加,后期降解反应占主导...     

聚酯纤维技术发展及前景探讨

从6个方面综述了近年来我国聚酯纤维的发展,并对发展前景进行了探讨。认为,锑系催化剂仍将会较长时间保留,特别是乙二醇锑应用前景广阔,但从环保出发,新型催化剂必须要研究开发。共缩聚改性应是聚酯改性的主流方法,而纳米无机粒子对面料和服装的表面处理以及微胶囊法制备功能纤维将会得到更大的发展。细旦化、超细旦化和异形化仍是聚酯纤维发展的重要趋势。聚酯纤维的发展取决于纺织加工中混纺技术的发展,后者将是未来聚酯面料制备的主要技术。实用的多组分复合技术将会有着良好的发展前景。重视聚酯的回收利用技术,也是聚酯纤维发展不可缺少的一环。     

PET酯化反应过程中的二甘醇生成

二甘醇(DEG)在聚对苯二甲酸乙二酯(PET)切片中的含量是PET的重要质量指标．在生产过程中必须严格控制。利用PET的工艺模拟模型,计算并分析了酯化反应器内DEG生成量及其影响因素,结果表明,第一酯化反应器出口的DEG质量分数为0．732％;第二酯化反应器出口的DEG质量分数为0．851％;影响DEG生成的反应因素按影响程度大小依次为：温度、配比、时间和压力。     

非纤用聚酯生产近况及发展趋势

介绍了世界非纤用聚酯的发展近况,重点分析了我国非纤用聚酯的生产情况,主要产品及用途,并对其应用和发展前景进行了论述。指出:随着经济的发展以及人民生活水平的提高,非纤用聚酯将在更多领域得到应用,并将为从事于非纤用聚酯生产的企业带来新的发展机遇。     

草酸亚锡体系中对PET稳定剂的研究

本文研究了草酸亚锡体系中几种单一稳定剂和复合稳定剂对PET副反应的抑制。采用磷酸、磷酸酯类或亚磷酸、亚磷酸酯类作为稳定剂,均能提高PET的热稳定性,改善树脂的质量指标;与酚类抗氧剂一起作为复合稳定剂,效果更佳。较好的草酸亚锡体系与实用的三氧化二锑体系的比较,表明在实际生产中草酸亚锡作为缩聚催化剂是很有前途的。     

PET瓶在茶饮料包装的应用及发展

介绍热灌装用PET瓶的主要性能和应用情况 ,并与其他各种包装材料进行对比。PET瓶具有优越的机械性能和对环境保护的适应性 ,并且大规模生产时成本较为低廉。二次吹瓶工艺繁琐 ,成本高 ,一次吹瓶工艺简单适用。预计今年国内热灌装PET瓶产量可望突破 10亿只     

Poly(ethylene terephthalate) Recycling and Recovery of Pure Terephthalic Acid. Kinetics of a Phase Transfer Catalyzed Alkaline Hydrolysis

Poly(ethylene terephthalate) (PET) taken from post‐consumer soft‐drink bottles was subjected to alkaline hydrolysis with aqueous sodium hydroxide after cutting it into small pieces (flakes). A phase transfer catalyst (trioctylmethylammonium bromide) was used in order the reaction to take place in atmospheric pressure and mild experimental conditions. Several different reaction kinetics parameters were studied, including temperature (70–95°C), NaOH concentration (5–15 wt.‐%), PET average particle size, catalyst to PET ratio and PET concentration. The disodium terephthalate received was treated with sulfuric acid and terephthalic acid (TPA) of high purity was separated. The ¹H NMR spectrum of the TPA revealed an about 2% admixture of isophthalic acid together with the pure 98% terephthalic acid. The purity of the TPA obtained was tested by determining its acidity and by polymerizing it with ethylene glycol using tetrabutyl titanate as catalyst. A simple theoretical model was developed to describe the hydrolysis rate. The apparent rate constant was inversely proportional to particle size and proportional to NaOH concentration and to the square root of the catalyst amount. The activation energy calculated was 83 kJ/mol. The method is very useful in recycling of PET bottles and other containers because nowadays, terephthalic acid is replacing dimethyl terephthalate (the traditional monomer) as the main monomer in the industrial production of PET.     

PET固相缩聚工艺技术分析

综述了聚酯(PET)固相缩聚过程特点,重点对比分析了Bepex、Buhler、Sinco及Dupont的NG3连续固相缩聚工艺、关键设备构型及主要操作参数。PET固相缩聚过程中结晶增长与缩聚反应共存并互相耦合,因而结晶工序是固相缩聚工艺的重要组成部分,也是各工艺专利商的专利技术之所在。有效的结晶增长、结晶形态与缩聚反应的解耦合是强化固相缩聚技术的科学基础。     

聚酯的生命周期评价

生命周期评价(LCA)是重要环境管理工具,阐述了PET产品生命周期评价的意义和应用,通过AMFA对PET纺织品生命周期评价研究要点说明PET生命周期评价的方法和步骤,并对我国PET的LCA研究提出建议。     

Structure controlling and process scale-up in the fabrication of nanomaterials

Nanotechnology is already having a significant commercial impact, and will very certainly have a much greater impact in the future. The research on process engineering and scale-up will be very important for the commercial production and application of nanomaterials, because the properties and structure of nanomaterials are not only determined by the nucleation and growth process, but also strongly affected by the engineering properties, such as the mixing, the heat and mass transfer, and also the distribution of temperature, concentration, etc. This paper will present some research work in our laboratory on the fabrication of nanomaterials. Based on the chemical engineering principle and methods, many kinds of novel nanomaterials can be synthesized and their structure can be easily controlled through adjusting the parameters of the fluid mixing, and the distribution of temperature, residence time and concentration, etc. By using the micro-mixing, heat and mass transfer and reaction control methods, the host-guest nanocomposites have been assembled and assumed as the novel electroanalytical sensing nanobiocomposite materials. Based on the principles of chemical engineering, the manufacturing technologies for magnetic powders, calcium carbonate, and titanium dioxide have been developed for commercial-scale production, and the largest production scale has reached 15 kt/year.     

Structure controlling and process scale-up in the fabrication of nanomaterials

Nanotechnology is already having a significant commercial impact, and will very certainly have a much greater impact in the future. The research on process engineering and scale-up will be very important for the commercial production and application of nanomaterials, because the properties and structure of nanomaterials are not only determined by the nucleation and growth process, but also strongly affected by the engineering properties, such as the mixing, the heat and mass transfer, and also the distribution of temperature, concentration, etc. This paper will present some research work in our laboratory on the fabrication of nanomaterials. Based on the chemical engineering principle and methods, many kinds of novel nanomaterials can be synthesized and their structure can be easily controlled through adjusting the parameters of the fluid mixing, and the distribution of temperature, residence time and concentration, etc. By using the micro-mixing, heat and mass transfer and reaction control methods, the host-guest nanocomposites have been assembled and assumed as the novel electroanalytical sensing nanobiocomposite materials. Based on the principles of chemical engineering, the manufacturing technologies for magnetic powders, calcium carbonate, and titanium dioxide have been developed for commercial-scale production, and the largest production scale has reached 15 kt/year.