我国聚四氢呋喃发展走上快车道

聚四氢呋喃是生产氨纶和聚氨酯材料的重要原料。介绍了聚四氢呋喃的新技术及国内外聚四氢蚨喃的发展情况。     

聚四氢呋喃醚二醇制备技术概况

重点介绍了目前聚四氢呋喃醚二醇几种主要的制备技术,具体包括：（1）高氯酸-酸酐法;（2）氟磺酸法;（3）杂多酸法;（4）糠醛法;（5）黏土法,并且比较分析了上述5种聚四氢呋喃醚二醇制备方法的优缺点及工艺改进的研究进展情况,还简要介绍了几种聚四氢呋喃醚二醇的衍生物及制备方法,最后对我国今后的聚四氢呋喃醚二醇工业发展提出了几点看法与建议。     

四氢呋喃均聚醚催化研究进展(续)

<正> (接上期第12页)3.2.2 无定型硅酸铝 硅酸铝是经过广泛研究的典型的二元氧化物,固体酸的概念也是通过对硅酸铝的研究而建立起来的。SiO2/AI2O3上的酸中心强度比H0=-8.2还强,且同时具有B酸和L酸2种酸型。20世纪90年代初,ARCO公司的Kahn[60]使用羧酸酐/无定型硅酸铝为催化体系,合成PTMEG。使用的羧酸酐可以是乙酸酐、内酸酐、邻苯二甲酸酐和马来酸酐。硅酸铝中铝质量分数为10％-30％,比表面积20-500m2/g。产物相对分子质量为200-5000,分布指数在3以下。     

四氢呋喃均聚醚催化研究进展

主要归纳和总结了四氢呋喃 (THF)阳离子开环聚合反应的各种催化体系 ,并对非匀相催化体系 ,尤其是杂多酸作了较为详细的叙述。     

聚四氢呋喃的经济概况及工艺进展(续)

2．2．5杂多酸（盐）催化剂 杂多酸（HPA）是一类酸度比浓H2SO4还高的质子酸,主要有H3PW12O40、H3PMo12O40、H4SiW12O40、H4SiMo12O40等。它具有结构稳定、易于制备和分离、易溶于水和多数有机溶剂、可回收利用等特点,因而备受重视。     

Microemulsion polymerization of styrene in the presence of macroinimer

The kinetics of o/w electrostatically and sterically-stabilized microemulsion polymerization of styrene with and without macromonomeric azoinitiator (macroinimer; MIM) have been investigated. The microemulsion polymerization stabilized by the ionic emulsifier sodium dodecyl sulfate (SDS) or the non-ionic emulsifier Tween 20 (Tw 20) was initiated by ammonium peroxodisulfate (APS)/sodium thiosulfate (STS) redox system. The rate of polymerization vs. conversion curve shows the two non-stationary rate intervals. This behavior is a result of two opposing effects, the continuous particle nucleation and the decrease of monomer concentration at the reaction loci. The addition of MIM favors the additional particle nucleation. The sterically (Tw 20)-stabilized microemulsion polymerization is much faster than that of the electrostatically (SDS)-stabilized microemulsion polymerization. This was attributed to the higher Tw 20 concentration and increased solubilization of MIM and comonomer concentration in the polymer particles. The formation of initial large polymer particles is attributed to the intensive agglomeration polymer particles with monomer droplets. The continuous decrease in the average size is mainly attributed to the additional particle nucleation.     

活性炭负载磷钨酸催化合成聚四氢呋喃

活性炭为载体制备了负载型磷钨酸催化剂,研究其在环氧氯丙烷的引发作用下催化四氢咬喃开环聚合的反应工艺.考察了反应时间、反应温度、四氢呋喃与环氧氯丙烷的质量比、催化剂的活化温度及催化剂用量对收率的影响,并分析了催化剂活性降低的原因.研究表明,最优反应条件为:反应时间为4h,反应温度为50℃,四氢呋喃与环氧氯丙烷的质量比为1...     

聚四氢呋喃的经济概况及工艺进展

聚四氢呋喃是合成氨纶和聚氨酯（PU）弹性体的主要原料,它可赋予制品优异的性能。详细介绍了聚四氢呋喃的国内外经济概况和生产工艺。当前主要采用固体酸作催化剂合成聚四氢呋喃,具有对设备腐蚀性小、不污染环境、易于再生、产物相对分子质量及分布可控等优点。     

Swelling and elasticity of hydrogels based on poly(ethylene oxide) macroinimer

A novel method for the preparation of hydrogels based on poly(ethylene oxide) (PEO) is presented. A PEO macroinimer possessing both polymerizable and radical generation sites was used to obtain hydrogels having dangling PEO chains. It was shown that PEO macroinimer acts during photopolymerization, both as a monomer and a crosslinker and thus, leads to the formation of hydrogels of various swelling capacities and moduli of elasticity. Copyright © 2004 Society of Chemical Industry     

1,4-丁二醇、聚四氢呋喃及其重点衍生物的开发现状

介绍了国内1,4-丁二醇、聚四氢呋喃重点衍生物的开发现状,简要叙述了一些企业采取的措施。     

负载型蒙脱土(Fe_2O_3/H-MMT)催化合成聚四氢呋喃

研究了蒙脱土(MMT)负载硝酸铁制备的固体酸催化剂(Fe2O3/H-MMT)在四氢呋喃(THF)开环聚合中的催化性能。考察了催化剂的制备条件和乙酸酐用量对催化活性和聚四氢呋喃(PTHF)粘均相对分子质量的影响。结果表明,在酸化处理用酸浓度为3.00 mo.lL-1,Fe2O3负载量为18%(质量分数),焙烧温度为400℃下制备的催化剂,反应5 h,催化活性为1.17 g.g-1Cat.h-1。催化活性随乙酸酐用量的增加而增大。催化剂的制备条件对PTHF的相对分子质量影响不大,受乙酸酐用量的影响。     

聚四氢呋喃的生产技术及国内外市场分析(下)

介绍了聚四氢呋喃的生产方法，分析了国内外聚四氢呋喃的生产消费现状及发展前景，提出了发展我国聚四氢呋喃生产的建议。     

Mechanical Characteristics and Thermal Decomposition Behaviors of Polytetrahydrofuran Binder with Glycerol Propoxylate (Mn=1500) as a Crosslinking Agent

Polytetrahydrofuran (PTHF) is an effective binder ingredient for improving propellant performance, although it is not an energetic material. PTHF becomes sufficiently rubbery for use as a binder when a triol is added as a crosslinking modifier. In this study, glycerol propoxylate (GPO), with a molecular weight of 1500, was used as a crosslinking modifier, and the curing behavior, tensile properties, and thermal decomposition behaviors of the PTHF binder with GPO were investigated. A PTHF (M _n=650)/GPO blend with a PTHF/GPO mole ratio (ξ ) less than or equal to 4 and a PTHF (M _n=1400)/GPO blend with ξ ≤1 were used as propellant binders. The curing behaviors and mechanical properties of the PTHF/GPO blends were influenced by the molecular weight of PTHF and ξ , while the thermal decomposition behaviors were not affected. It was found that the PTHF/GPO blends had higher initial viscosity, longer pot life, and unique mechanical properties compared to those of the PTHF blends supplemented with GPO (M _n=260).     

Reactions of Living Polytetrahydrofuran with Amines V - Tertiary Amine Terminated Polybutadienes; The Synthesis of Novel Ionically Linked Block Copolymers

The reactions of mono- and difunctional tertiary amine ended polybutadienes with mono- and difunctional living cationic poly THF have been studied. It is shown that the reaction to form quaternary ammonium linking groups takes place rapidly in all cases, and AB. ABA, BAB and (AB) block copolymers have been prepared. The efficiency of the process is extremely high and the degree of conversion is essentially controlled by the efficiency with which the terminal tertiary amine groups can be introduced on to the polybutadiene. The block copolymers show anomalous behaviour on gel permeation chromatography columns and this has been related to a specific interaction of the created ionic groups with polar species on the column packing. This effect is greatest with (AB) block copolymers where substantial proportions are retained indefinitely on the columns.     

Mechanical Characteristics and Thermal Decomposition Behavior of Polytetrahydrofuran Binder using Glycerol Propoxylate (Mn=260) as Crosslinking Agent

Polytetrahydrofuran (PTHF) is an effective binder ingredient for improving propellant performance, even though it is not an energetic material. PTHF becomes sufficiently rubbery for use as a binder when a triol material such as glycerin is added as a crosslinking modifier. The cured PTHF/glycerin binder had unsatisfactory mechanical characteristics for use as a propellant binder, so a more appropriate crosslinking modifier than glycerin needs to be found. In this study, glycerol propoxylate (GPO), with a molecular weight of 260, was used as a crosslinking modifier, and the curing behavior, tensile properties, and thermal decomposition behaviors of the PTHF binder using GPO were investigated. The PTHF/GPO blend did not solidify when the PTHF/GPO mole ratio (ξ) was greater than a certain value. The PTHF (M_n=650)/GPO blend with ξ≤5 and the PTHF (M_n=1400)/GPO blend with ξ≤3 were used as propellant binders. From the curing behaviors and tensile properties, it was found that the PTHF/GPO binders ensured optimal mixing of the propellant ingredients and casting of the uncured propellant into the rocket motor case, and the tensile properties of the binders changed more drastically with the variation in ξ than did those of the PTHF/glycerin binders. The thermal decomposition behaviors of the PTHF/GPO binders were hardly dependent on ξ and were almost identical to those of the PTHF/glycerin binders.     

Thermal Decomposition Behaviors and Burning Characteristics of Ammonium Nitrate/Polytetrahydrofuran/Glycerin–based Composite Propellants Supplemented with MnO2 and Fe2O3

Although a polytetrahydrofuran (PTHF) blend with added glycerin as a crosslinking modifier is an effective binder for improving the performance of a propellant, a burning catalyst is required for the combustion of the ammonium nitrate (AN)/PTHF/glycerin propellant. MnO₂ and Fe₂O₃ are useful burning catalysts for AN‐based propellants. The thermal decomposition behaviors of the AN/PTHF/glycerin propellant supplemented with MnO₂ and Fe₂O₃ catalysts, and the catalytic effect of these catalysts on the burning characteristics was investigated in this study. The thermal decomposition behaviors of these propellants depended on the kind of catalyst used. The propellants containing MnO₂ burned above 4 MPa, while those containing Fe₂O₃ burned above 0.5 MPa. The burning rate increased in the order, (AN/PTHF/Fe₂O₃)<(AN/PTHF/MnO₂)<(AN/PTHF/MnO₂/Fe₂O₃). The improvement in the ignitability and burning rate was dependent on the kind of catalyst used. The burning characteristics of the AN/PTHF/glycerin propellants were improved by the combined effect of multiple catalysts with differing catalytic mechanisms, as compared to the propellant supplemented with any single catalyst.