废旧聚酯瓶的固相缩聚增粘

本文以废旧聚酯瓶为原料，采用固相缩聚的方法，合成了特性粘度０．７－１．２范围的高分子量ＰＥＴ，使回收的聚酯瓶得以重新被利用。研究了聚合温度，聚合时间，原料颗粒度，真空度等对固相聚合速度的影响。初步探讨了固相聚合的机理和较佳的工艺参数，为废旧聚酯瓶的回收打下了基础。     

固相缩聚生产高粘度聚酯

叙述了高粘度聚酯的发展概况以及制造工艺,并重点阐述了影响固相缩聚生产高粘度聚酯反应的主要因素。指出聚酯固相缩聚应选择合理的原料路线,严格精选切片颗粒大小及预聚体切片结晶度(预聚体极限密度控制为1.38g/cm~3);根据最终产品需要选取不同的催化体系并通过调整 PTA/EG 配比控制预聚体中醚键含量;反应温度及反应时间是固相缩聚反应的主导影响因素,但控制反应中副产物的去除是破坏反应平衡、提高固相缩聚表观反应速率的重要手段。     

聚酯固相缩聚技术进展

简略地介绍了聚酯固相缩聚的起源、演变和发展趋势,剖析各种聚酯团相聚合设备的优点和弊端,着重介绍了美国H—Bepex公司第三代结晶器——串联Disc盘状结晶器和第四代结晶器——远红外结晶器,这种远红外结晶器既能有效地避免切片的粘结又能有效地抑制粉尘的产生。并就氮气净化技术对目前国际上采用的种种方法进行了简明扼要的比较。     

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。     

PET间歇固相增粘工艺的优化

介绍了仪化佛山聚酯有限公司7000t／a间歇固相增粘装置工艺参数优化情况。总结了优化后的质量、产量情况。     

共聚酯的固相缩聚研究

本文通过固相缩聚的方法制得了较高特性粘度的共聚酯,用二级反应动力学方程进行数据处理时发现,在较低反应温度(210℃和195℃)或较短反应时间时,线性符合较好;而在较高反应温度、较长反应时间时,则结果偏离线性.用DSC测得双熔融峰,随反应时间延长,样品低温峰向高温方向移动,这与以前的研究结果是一致的;但本实验得到的高温峰向低温方向移动,这一结果则与文献报道的不一致,一般来说,高温峰应保持峰温不变.因此有关固相缩聚后聚酯的熔融行为有待进一步系统研究.     

年产4万t聚酯连续固相缩聚国产化技术

介绍北京燕化公司年产4万t聚酯装置的设备特点和工艺过程。并联预结晶器,设备无搅拌,循环氮气经过冷却罐换热后再进反应器,器内切片柱塞流流动、气体分配器使气体分布均匀、采用导热油加热、低速密相脉冲输送切片等。本装置物耗、公用工程消耗低,产品质量高,达到或超过国外同类装置的水平。     

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     

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。     

基于熔融/固相缩聚制备中高分子量聚乙醇酸

聚乙醇酸（PGA）通常可通过乙交酯开环聚合和乙醇酸熔融缩聚制得,但乙交酯开环聚合工艺复杂,导致PGA成本高。相较而言,乙醇酸熔融缩聚制备PGA工艺简单,成本较低,但难以获得中高分子量的PGA。因此,本文基于熔融/固相缩聚路线,系统研究了催化剂种类与含量、酯化温度、固相缩聚温度等聚合工艺条件对PGA外观形态、特性黏度和热稳定性的影响。发现三氟甲烷磺酸铋对乙醇酸熔融缩聚具有较好的催化效果,优化熔融/固相缩聚条件如下：催化剂含量为0.20%（质量）,酯化温度为180℃,熔融缩聚和固相缩聚温度为210℃,固相缩聚时间为12 h。在该熔融缩聚条件下,PGA的最高特性黏度为0.36 dl/g,进一步固相缩聚处理可以将PGA的特性黏度提高到0.59 dl/g。     

Branched aliphatic polyesters by ring-opening (co)polymerization

The rapid development of biodegradable and biocompatible materials for biomedical applications is reflected in the search for new methods for aliphatic polyester modification applicable in this field. One possible approach is modification by changes to the polymer topology.This review covers the main methods of synthesis of branched aliphatic biodegradable and biocompatible (co)polyesters, where the ring-opening polymerization (ROP) of cyclic esters or cyclic carbonates is the leading process. First, literature examples of ring-opening multibranching polymerization (ROMBP) of AB₂-type hydroxyl-substituted cyclic lactones, lactides and carbonates are cited followed by the presentation of the application of AB-type cyclic esters and additionally AB₂ cyclic ethers or esters as “branching monomers” for the synthesis of branched polyesters based on polycaprolactone (PCL), polylactide (PLA) and polyglycolide (PGA). In the following part, methods involving the combination of the ROP of AB-type cyclic esters and condensation processes leading to branched structures are summarized. Other related strategies leading to “dendri-star” or “core–shell” copolyesters are also discussed. Several examples of approaches to PCL and PLA graft copolymer syntheses are also shown. The advantages and disadvantages of the presented methodologies of branched polyester synthesis are highlighted. Finally, the influence of the branched structure on the properties of the presented class of polyesters, important from the application point of view, is considered.     

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。     

PET固相缩聚反应器动态模型

PET固相缩聚过程涉及反应固体颗粒和反应器床层两个空间尺度的传质,是一个复杂的多维多相对象。以反应过程控制为目标,在已有的反应动力学模型基础上,同时考虑可逆化学反应和小分子产物内外扩散两个控制因素,并借用固定床拟均相模型的建模思想,将小分子产物在颗粒内外扩散形成的浓度梯度用一个有效系数来表示,从而建立了简化的PET固相缩聚反应器一维动态模型。在相关文献的实验条件下求解分布参数模型的数值解,并进行启动过程仿真和过程动态分析,计算反应器出口质量指标,与文献曲线和数据对照,验证了模型的正确性。     

Synthesis of new polyesters with chelating subunits by solution and interfacial polycondensation

New polyesters have been prepared by solution and interfacial polycondensation of acid chlorides obtained from bis‐α,ω‐polymethylene‐[(2‐methoxy)phenoxy]acetic acids, acid‐ether siderophores AE _n (n being the number of methylene units), and diols including bisphenol A, ethylene glycol and propanediol. For interfacial polycondensation, average molecular weights range from 1000 to 4500 g mol^?1; at higher temperature the molecular weights increase but the yield is smaller. Differential scanning calorimetry shows T_g ranging from ?5 to + 110 °C. Polyesters are crystalline with n = 6 and amorphous with n = 2 and 4; in addition, increasing n in AE _n increases molecular weights and T_g values. In solution polycondensation, the average molecular weights are around 3000 g mol^?1 and T_g is low. © 2001 Society of Chemical Industry     

工业丝级PET固相增黏切片生产工艺的探讨

以已投产的年产万吨级连续固相缩聚装置生产工业丝级涤纶增黏切片实测的反应条件为依据,从原料切片、反应温度、停留时间、循环氮气纯度及流量等因素对固相缩聚反应的影响,详细地对连续固相缩聚生产工业丝级涤纶增黏切片的生产工艺加以探讨。     

Kinetic and property parameters of poly(ethylene naphthalate) synthesized by solid-state polycondensation

A low molecular weight prepolymer with reactive end groups was annealed at temperatures between 200 and 245°C to obtain kinetic parameters for solid-state polymerization of poly(ethylene naphthalate) (PEN). An equation was developed to describe the relationships among time, temperature, and final molecular weight for PEN. The intrinsic viscosity and melting point during polymerization were used to monitor the molecular weight and the thermal stability of the resulting resins. The effect of moisture concentration on solid-state polymerization was also investigated. Hydrolytic degradation caused initial reductions of the molecular weight if prepolymers were solid-stated without being dried. With increased exposure to solid-state conditions, however, the hydrolytically degraded resin dried and repolymerized at rates similar to those samples that had undergone hydrolysis. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2055–2061, 2001     

Liquid crystalline polyesters by staged-addition polycondensation

Summary A series of model liquid crystalline (LC) polyesters have been prepared by low temperature solution polycondensation using staged addition methods. The model thermotropic polyesters were composed of aliphatic spacers and mesogenic groups made from substituted terephthalic acid and methyl hydroquinone. Both the mesogenic groups and the spacers were placed in the main chain. Attractive properties of these polymers include solubility in many organic solvents such as THF and DMSO with softening temperatures below 150°C. Some of these polymers show no melting transitions, and depending on the terephthalate group substituent, either smectic or nematic phases are formed. Results from GPC analysis show good solubility of polymers in THF with M_w lower than 10,000 compared to polystyrene standards. The synthesis and characterization of these LC polyesters are reported here.     

固相缩聚对PET切片结晶度及粘度的影响

研究了PET连续式固相缩聚反应中升温速度、反应温度和反应时间对切片预结晶度及特性粘数的影响。切片预结晶度随升温速度的增大而逐步降低 ,特性粘数随反应时间的延长或反应温度的升高而增大。实际生产中 ,较佳的反应温度 2 10～ 2 3 0℃ ,升温速度小于 3 0℃ /min ,反应时间 2 3h。     

聚L-乳酸固相缩聚工艺研究

以L-乳酸为原料,采用复合催化剂熔融缩聚的方法,制备预聚物,然后进行固相缩聚研究。研究了抽真空和通氮气2种固相缩聚工艺方法。在通氮气工艺方法中探讨了反应温度、反应时间、物料颗粒的尺寸等对固相缩聚反应的黏均相对分子质量的影响。根据缩聚反应平衡和水分子扩散传质平衡的原理对实验现象进行了合理的解释。