Aromatic polyureas and polythioureas by a new polycondensation reaction using ethylene chlorophosphite as reagent

Summary Aromatic polyureas and polythioureas are prepared from aromatic diamines and carbon dioxide or carbon disulfide, by a new direct polycondensation reaction with, ethylene chlorophosphite as reagent in pyridine as solvent and acceptor for hydrochloric.     

缩聚催化剂乙二醇锑的应用

介绍了聚酯缩聚催化剂乙二醇锑在上海石化涤纶部的试用和推广应用过程 ,讲述了乙二醇锑的配制和添加的特点 ,对聚酯生产过程和对聚酯产品的影响 ,以及乙二醇锑的聚酯产品对纺丝后加工性能的影响。     

新Hantzsch试剂对甲基-N-乙酰乙酰苯胺荧光法测定微量甲醛

介绍了一种基于Hantzsch反应测定微量甲醛的新试剂,对甲基-N-乙酰乙酰苯胺(AAPT).采用AAPT的Hantzsch反应可在室温下进行.产物可用荧光法进行检测,产物的最大激发与发射波长分别为385和450 nm.对反应温度、乙醇用量和pH进行优化后,建立了测定微量甲醛的AAPT荧光法.甲醛浓度在3.0 ×10-...     

原位缩聚合成含聚芳酰胺／酯的微相复合物 Ⅴ．共聚酰胺与聚砜的微相复合物制备

用原位缩聚法合成了芳香-脂肪共聚酰胺与聚砜的徽相复合物(PAA／PSF)。初步结果表明:PAA／PSF微相复合物具有热致液晶性能;PAA的加入大大提高了微相复合物的力学性能。以PA30(PAA=29．5ω)为例,拉伸强度和模量分别提高到原来的2．5倍和3．5倍。     

Properties and phase separation of reaction injection molded and solution polymerized polyureas as a function of hard block content

A series of amine terminated polypropylene oxide based thermoplastic polyureas with hard segment contents of 30%, 50%, and 70 percent were synthesized via solution polymerization and reaction injection molding (RIM). Amine terminated polypropylene oxide (PPO-NH₂) of M_n = 2000 was used as the soft segment and 4,4′-diphenylme-thanediisocyanate (MDI) extended with diethyltoluenediamine (DETDA) as the hard segment. These polyureas are linear, amorphous, and phase separated. Polymers were characterized by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), dynamic mechanical spectroscopy (DMS), small angle X-ray scattering (SAXS), and tensile testing. RIM polyureas had significantly lower molecular weights than solution polymerized polyureas, but their mechanical properties did not suffer, RIM polyureas have poorer phase separation than solution polyureas as evidenced by DSC, DMS, and SAXS, especially at high hard segment levels. SAXS shows phase separation levels of up to 100 percent for low hard segment polyureas and down to 10 percent for high hard segment RIM polyurea. DSC found no evidence of a hard segment glass transition, and the evidence from DMS was inconclusive. In addition to polymer characterization, demolding behavior was studied. The 30 percent hard segment was always tough and elastomeric, while the 70 percent hard segment was always very brittle. The 50 percent hard segment showed the greatest variation in properties, ranging from very brittle to very though as mold temperature and in-mold time were increased. Demold brittleness is explained by the presence of low molecular weight DETDA/MDI oligomers on demolding, which continue to react on aging.     

Preparation of cellulosic ion exchange fiber using an ionic liquid as reaction reagent and medium

A cellulosic ion exchange fiber (CIEF) was prepared by using room‐temperature ionic liquid 1‐(3‐chloro‐2‐hydroxypropyl)‐3‐methylimidazolium chloride as reaction reagent and medium. The results showed the degree of substitution of the CIEF was up to 0.78. The product was characterized by Fourier transform infrared spectrometry, thermogravimetric analysis, scanning electronic microscope. The thermal stability of the CIEF was over 200°C. The adsorption experiments of CIEF for Cr(VI) were performed. The adsorption capacity of CIEF for Cr(VI) was found to be 196.1 mg g^?1 at 30°C. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

新安替比林偶氮试剂的合成及对其与铋高灵敏显色反应的研究

合成了新显色剂２－（４－安替比林偶氮）－４，５－二羧甲氧基苯甲酸（ＡＡＤＣＢ），发现其与Ｂｉ~３＋能发生高灵敏的显色反应，ε＝３５×１０~４·ｍｏｌ~－１·ｃｍ－１，且表现出较好的选择性。     

缩聚反应时间优化分析

分析了改变一定负荷下同样大小的圆盘反应器物料停留时间(液位)对缩聚反应、产品分子质量分布、b值、运行电流的影响,指出在一定负荷下对圆盘反应器缩聚反应时间进行优化的必要性和调节手段。     

Hydrolysis reaction of poly(ethylene terephthalate) using ionic liquids as solvent and catalyst

The hydrolysis of poly(ethylene terephthalate) (PET) was studied using ionic liquid 1‐n‐butyl‐3‐methylimidazolium chloride ([Bmim][Cl]) as solvent and acid‐functionalized ionic liquid 1‐methyl‐3‐(3‐sulfopropyl)‐imidazolium hydrogen sulfate ([HSOpmim][HSO₄]) as catalyst. The effects of temperature, time, and dosages of solvent and catalyst on hydrolysis results were examined. Under the optimum conditions of m(PET) : m(H₂O) : m([Bmim][Cl]) : m([HSOpmim][HSO₄]) = 3 : 4 : 6 : 0.6, reaction temperature 170°C and time 4.5 h, the conversion of PET and the yield of terephthalic acid (TPA) were almost 100% and ≥88%, respectively. After easily separated from the product, the ionic liquids could be reused eight times without obvious decrease in the conversion of PET and yield of TPA. Hence, an environmental friendly strategy for chemical recycling of PET was developed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

新试剂1-(2-羟基-5-硝基苯基)重氮氨基偶氮苯的合成及其与镉的显色反应

合成了新试剂1-(2-羟基-5-硝基苯基)重氮氨基偶氮苯(HNPDAAB),并研究了它与镉的显色反应。在Triton X-100存在下,pH8.5～10.0的Na2B4O7-NaOH缓冲溶液中,试剂与镉生成1:1型深红色配合物,其表观摩尔吸光系数达1.66×105L·mol-1·cm-1。Cd2+的含量在0～9μg/25ml,范围内符合比尔定律。     

新杂环三氮烯试剂BTBPT的合成及其与镉(Ⅱ)的显色反应研究

合成了一种新的杂环三氮烯显色剂1-(2-苯并噻唑)-3-(4-溴苯)-三氮烯(BTBPT)。在Na2B4O7-NaOH缓冲介质中,BTBPT在非离子表面活性剂Triton X-100存在下与Cd形成1:2的稳定配合物,其表观摩尔吸光系数为1.75×105L·mol-1·cm-1,镉量在0～10μg/25mL范围内遵守比尔定律。方法应用于废水样中CA2’的测定,获得了较为满意的结果。     

阿拉伯树胶增敏-新试剂对碘偶氮氯膦与铋离子显色反应的研究与应用

在pH =2 0的HCl-HAc介质中 ,对碘偶氮氯膦与Bi3 + 生成蓝紫色的配合物 ,其最大吸收波长的位置在 6 84nm ,摩尔吸光系数为 1 15× 10 4,Bi3 + 浓度在 0～ 5mg/L范围内符合比尔定律。表面活性剂具有增敏作用 ,在测定条件下 ,加入 0 5 %的阿拉伯树胶 2mL ,其线形回归方程为c =- 1 0 74 +3 5 5 7A(mg/L)。     

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     

新试剂二甲基苯基重氮氨基偶氮苯与镉的显色反应研究及其应用

研究了新试剂二甲基苯基重氮氨基偶氯苯（ＤＭＰＤＡＢ）的一些性质以及它与镉的显色反应。在ＴｒｉｔｏｎＸ－１００存在下，ｐＨ为８．５～１０时，镉与试剂形成桔红色１：２型配合物。最大吸收位于５２４ｎｍ，摩尔吸光系数为１．９×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，Ｃｄ（Ⅱ）在０～２０μｇ／２５ｍＬ符合比耳定律。直接测定了天然水中的镉，标准加入回收率％～１０３％，相对标准偏差为１．５％。     

A study of interfacial polycondensation in a continuous reaction system

A study was made of the interfacial polycondensation of nylon 6–10 in a continuous reaction system since no previous detailed work of this type was reported in the literature. An experimental stirred-flow reactor was used to determine both yield and intrinsic viscosity (molecular weight) as functions of reactant ratio (sebacoyl chloride/hexamethylenediamine) and Reynolds number. It was found that mass transfer was the controlling factor in the reaction system. The yield as a function of Reynolds number correlated directly with the behavior of mass transfer coefficient. In addition, reactant ratio effects on yield were shown to relate to change in organic phase volume. Intrinsic viscosity was a maximum in the same reactant ratio range as for batch and continuous cascade systems studied earlier. Intrinsic viscosity behavior was also shown to relate to mass transfer. The j_D data for the reactor systems were also determined. These values were shown to correlate if normalized for reactant ratio.     

Oligomerization of ethylene on platinum by a two-step reaction sequence

On Pt, substantial fractions of chemisorbed C₂h₄ can be converted to C₃₊ alkanes by subsequent hydrogenation. The absence of H₂ during chemisorption is considered as the main factor favoring C-C bonding between adsorbed species, whereas its further addition permits higher alkanes to be released.     

新显色剂二溴对甲基偶氮溴磺的合成及其与铅显色反应的研究

报道了新显色剂二溴对甲基偶氮溴磺的合成方法.研究了在酸性介质中,新显色剂与铅的反应,在0.24mol·L磷酸介质中,显色剂与铅(Ⅱ)形成2∶1蓝色配合物,其最大吸收波长为638nm,表观摩尔吸光系数为8.44×10L·mol·cm,铅含量在0-25μg/25mL范围内符合比耳定律.拟定的方法用于铜合金中微量铅的测定,结果满意.     

Melt polycondensation of poly(ethylene terephthalate) in a rotating disk reactor

A multicompartment model is proposed for a semibatch melt polycondensation of poly(ethylene terephthalate) in a rotating disk polymerization reactor and compared with laboratory experimental data. The reactor is a horizontal cylindrical vessel with a horizontal shaft on which multiple disks are mounted. The reactor is assumed to comprise N equal sized compartments and each compartment consists of a film phase on the rotating disk and a bulk phase in which disks are partially immersed. The effects of disk rotating speed, number of disks, reaction temperature, and pressure were investigated. It was observed that ethylene glycol is predominantly removed from thin polymer layers on the rotating disks and the enhanced interfacial area exerted by ethylene glycol bubbles accounts for about 30–50% of the total available interfacial mass transfer area. Although the rate of polymerization increases as more disks are used, the maximum number of disks in a reactor must be determined properly in order to prevent the formation of thick polymer films that result in a reduced specific interfacial area and reduced polymerization efficiency. At a fixed reaction pressure, the equilibrium conversion is reached but the rate of reaction can be further increased by increasing the reaction temperature. The results of the proposed multicompartment model are also compared with those predicted by a simple one-parameter model. © 1995 John Wiley & Sons, Inc.     

有机锡催化碳酸乙烯酯与丁二酸二甲酯耦合反应

以含有不同取代基的有机锡化合物为催化剂,通过碳酸乙烯酯（EC）与丁二酸二甲酯（DMSu）耦合法制备了聚丁二酸乙二醇酯（PES）和碳酸二甲酯（DMC）,并对PES的结构进行了表征。结果表明,有机锡取代基团的电子效应和空间位阻对其催化性能具有很大影响;取代基的吸电子效应越大、空间位阻越小,有机锡的催化活性越高,但若有机锡中存在B酸中心时则容易引起副反应,导致产物选择性差。综合考虑,Bu₂SnO的催化性能最好,最优反应条件下,DMC的收率可达到70.08%,PES的特性黏数可达到0.622 dl·g^-1。     

邻羟基萘醛缩氨基硫脲的合成及其与铍的荧光熄灭反应的研究及应用

合成了新型的荧光试剂邻羟基萘醛缩氨基硫脲。该试剂与碱土金属(Be，Mg，Ca，Sr，Ba)离子能形成配合物，从而使该试剂λex/em=406／460nm的荧光熄灭，其荧光的熄灭程度随碱土金属离子半径的减小而增大。利用此配合反应建立了铍的分析方法，铍量在0～40μg／L范围内与△IF成线性关系。检出限为1．42μg／L；测定的相对标准偏差为0．86％。考察了30多种共存组分的干扰情况，方法成功地用于水和土壤样品中痕量铍的测定。