羧基化环氧丙烯酸酯合成及在光成像阻焊油墨中的应用

树脂;多元羧酸酐;光固化;碱显影;羧基化环氧丙烯酸酯合成及在光成像阻焊油墨中的应用     

Preparation of poly(glycidylmethacrylate‐divinylbenzene) weak acid cation exchange stationary phases with succinic anhydride,phthalic anhydride,and maleic anhydride for ion chromatography

In this work, poly(glycidylmethacrylate‐divinylbenzene) microspheres were prepared and applied for the preparation of weak acid cation exchange stationary phases. Succinic anhydride, phthalic anhydride, and maleic anhydride were selected as carboxylation reagents to prepare three weak acid cation exchangers by direct chemical derivatization reaction without solvent or catalyst. The diameters and dispersity of the microspheres were characterized by scanning electron microscopy; the amount of accessible epoxy groups and mechanical stability were also measured. The weak acid cation exchangers were characterized by Fourier transform infrared spectroscopy; the content of carboxyl groups was measured by traditional acid base titration method. The chromatographic properties were characterized and compared by separating alkali, alkaline earth metal ions and ammonium and polar amines. The separation properties enhanced in the order of succinic anhydride, phthalic anhydride, and maleic anhydride modified poly(glycidylmethacrylate‐divinylbenzene) cation exchangers.     

Syntheses of flame-retarding 4-phosphonatomethyl-2,6-dibromophenyl trimellitate anhydrides and their reactivities toward epoxy resin

4-Phosphonatomethyl-2,6-dibromophenyl trimellitate anhydrides (HDBBP–TMA) were prepared by the condensation of 4-chloroformyl phthalic anhydride with corresponding 4-hydroxy-3,5-dibromobenzyl phosphonates (HDBBP). These materials could be used to produce excellent flame retardance in epoxy resins when the substances were chemically combined with the polymer. The reactive-type HDBBP–TMA showed much better phosphorus–bromine synergistic effects on the flame retardancy of epoxy resins than the additive-type compounds such as HDBBP or the mixture of bromo compound (such as 2,6-dibromo-p-cresol) and phosphorus compound (such as triphenyl phosphite). Meanwhile, the oxygen index of cured epoxy resin was proved to be relative to the extent of crosslinking. Reactivities of HDBBP–TMA toward epoxy were also studied by rheometer in comparison with those of trimellitic anhydride and its derivatives such as 4-methylphenyl trimellitate anhydride and 4-methyl-2,6-dibromophenyl trimellitate anhydride.     

Synthesis and properties of thermally reversible polyesters

Thermally reversible polyesters were obtained by the ester formation reaction of thermoplastic polyesters with hydroxyl end groups and the diacid anhydride of tetra carboxylic acid as a thermally reversible chain extender. Typical example of the thermally reversible polyesters was obtained by the reaction of PBT (polyburylene terephthalate) and PMA (pyromellitic dianhydride). This material having twice as large molecular weight as the original PBT exhibited almost the same melt viscosity as the original. Also that thermally reversible chain extension reaction occurred without unfavorable side reaction such as cross-linking. This material shows both good processability and superior mechanical properties due to its thermally reversible characters.     

Hydrolytic stability of oligoesters: comparison of steric with anchimeric effects

A comparison of steric and anchimeric effects on the hydrolytic stability of polyesters was studied. Twelve monomers were selected based on their propensity toward steric and anchimeric interactions: adipic acid, isophthalic acid, phthalic anhydride, hexahydrophthalic anhydride, 1,4-cyclohexanedicarboxylic acid, maleic anhydride, ethylene glycol, 1,2-propanediol, 1,3-propanediol 1,4-butanediol, 1,5-pentanediol, and neopentyl glycol. Hydroxyl terminated oligoesters consisting of one diacid and one diol and one hydroxyl terminated oligoester consisting of two diacids and one diol were prepared. The hydrolytic stability was evaluated in an acetone/water solution. The acid number was monitored as a function of time. It was found that telechelic groups favor anchimeric interactions, while steric groups determine the rate of hydrolysis for the main chain.     

Determination of organic hydroxyl and amino compounds with o-sulphobenzoic anhydride

The determination of alcoholic hydroxyl groups by acylation with o-sulphobenzoic anhydride in dioxane medium is proposed. Quantitative esterification was generally obtained by refluxing for 2–3 h. No interferences were found from water, aldehydes, ketoncs, ethers, esters and phenols ; the reagent appeared to be of the phthalic anhydride type. Results for 26 hydroxyl and some amino compounds by the proposed reagent are given.     

甘草次酸衍生物的合成

豆科植物甘草中含有大量甘草次酸(Glycyrrhetinic Acid)。近代药理实验表明,甘草的抗炎症、抗溃疡以及抗变态反应等功效,主要归因于甘草中所含的甘草甜素,甘草次酸及其衍生物。多年来,国内外学者对甘草次酸     

Amine/anhydride reaction versus amide/anhydride reaction in polyamide/anhydride carriers

Polyamide 6 (PA6) and poly(metaxylene adipamide) (PAmXD6) were blended in a batch mixer with anhydrides such as phthalic anhydride, n-octadecyl succinic anhydride, and anhydride-grafted ethylene propylene rubber. The melt viscosity, the solution viscosity, and chain end concentration were studied during the mixing. PA was first mixed 5 min to get an homogeneous melt prior to the anhydride addition. The introduction of the anhydride to the molten polyamide resulted in large decreases of melt and solution viscosities and of amine chain end concentrations. The anhydride units react with amine chain ends to form imide groups. The resulting low amine chain end concentration causes hydrolysis reaction to maintain the condensation equilibrium. As a consequence an increased carboxylic chain end concentration is observed. The imide concentration was studied by IR. It was shown that when most of the amine chain ends are consumed, the remaining anhydride reacts with amino groups formed by polyamide hydrolysis. © 1995 John Wiley & Sons, Inc.     

Maleic anhydride as a reagent for the determination of hydroxyl groups in organic compounds

The reaction of esterification by maleic anhydride in methyl ethyl ketone in the presence of triethylamine is proposed for the determination of alcohol hydroxyl groups. The equivalent amount of maleic anhydride that entered into the reaction is determined spectrophotometrically by the reaction with 2-methylimidazole. In the determination of hydroxyl groups in epoxy-dian resins, maleic anhydride is determined by the potentiometric titration with alkali after hydrolysis with water by the first potential jump.     

Anhydride curing of epoxy resins via chain reaction

In contrast to common curing reactions, the anhydride curing of epoxies follows a living anionic chain growth. The resulting consequences of this mechanism, i.e. (1) DP_n = a[M_o]/[I_o], (2) first-order kinetics and (3) Poisson chain-length distribution were tested with the phenyl glycidyl ether/phthalic acid anhydride system, using l-methyl imidazole. Overall agreement was found and the observed deviations could be explained with a modified Poisson process. Conformational properties of the resins were measured by static and dynamic light scattering and by viscometry. These were compared with the quantities of a corresponding branched system prepared with a mixture of phenyl glycidyl ether and bisphenol-A diglycidyl ether. Typical deviations to smaller dimensions were observed at high molar masses as a result of increasing branching.     

Photo-oxidation products of polyetherimide ULTEM determined by MALDI-TOF-MS. Kinetics and mechanisms

Poly 2,2-bis4-(3,4-dicarboxyphenoxy) phenylpropane dianhydride-1,3-phenylendiamine copolymer (ULTEM) was subjected to photo aging in the attempt to find evidence on the structure of the species formed in the oxidative degradation. The oxidation was followed as a function of the exposure time by MALDI and SEC/MALDI techniques. The SEC curves showed extensive degradation, with the formation of low molar mass oligomers having different end groups. Valuable structural information on the photo-oxidized ULTEM species was extracted from the MALDI spectra of the photo-oxidized ULTEM. These showed the presence of polymer chains containing acetophenone, phenyl acetic acid, phenols, benzoic acid, phthalic anhydride and phthalic acid end groups. The mechanisms accounting for the formation of photo-oxidation products involve several simultaneous reactions: (1) photo-cleavage of methyl groups of the N-methyl phthalimide terminal units; (2) photoxidative degradation of the isopropylidene bridge of BPA units; (3) photo-oxidation of phthalimide units to phthalic anhydride end groups: (4) hydrolysis of phthalic anhydride end groups. The kinetic behaviour of all the species detected is in agreement with the predictions of the reaction mechanisms hypothesized.     

共聚结构和分子量对热塑性聚酰亚胺树脂熔融与耐热性能的影响

基于具有刚性主链结构的4,4'-(六氟亚异丙基)双邻苯二甲酸酐/对苯二胺(6FDA/p-PDA)树脂体系, 通过共聚引入间苯二胺(m-PDA)、 4,4'-二氨基-2,2'-双三氟甲基联苯(TFDB)和9,9'-双(4-氨基苯基)芴(BAFL)等主链刚性且兼具大自由体积特性的芳香二胺, 以非反应性封端剂邻苯二甲酸酐(PA)对分子量进行调控, 设计制备了系列分子量可控的热塑性聚酰亚胺(TPI)树脂. 系统研究了共聚结构和分子量对TPI树脂熔融性能和耐热性能的影响, 构建了聚合物的聚集态结构与树脂熔融性能的对应关系, 并对树脂的室温和高温力学性能进行了评价. 研究结果表明, 大自由体积的芳香二胺共聚结构的引入可有效降低分子链堆砌密度, 增大聚合物的自由体积, 从而赋予树脂良好的熔融性能. 降低设计分子量可进一步改善树脂的熔融加工性. 这类具有刚性主链结构的TPI树脂兼具优异的耐热性能和力学性能, 树脂的玻璃化转变温度在308~338 ℃之间, 以TFDB和BAFL共聚制备的TPI-C-25K和TPI-D-25K树脂表现出高强高韧的特性, 拉伸和弯曲强度分别超过120 MPa和190 MPa, 断裂伸长率大于8.2%, 并且在250 ℃高温下表现出良好的耐热稳定性.     

Thermal stability and structure of a new co-crystal of theophylline formed with phthalic acid

A new co-crystal of theophylline and phthalic acid with 1:1 molar ratio has been prepared. It crystallises in the monoclinic crystal system, space group P2₁/c, a=11.5258(9), b=10.1405(6), c=13.9066(12) Å, β=106.827(4)°. The structure of the co-crystal has been revealed by single crystal X-ray diffraction. An infinite helical polymeric chain is formed by intermolecular hydrogen bonds of the two neutral constituents. The hydroxyl group and carbonyl oxygen atom in one of the carboxyl groups of phthalic acid form hydrogen bonds to O6 and to N(7)H atoms of theophylline, respectively, while the other carboxyl OH group of phthalic acid is in hydrogen bond to N9 atom of theophylline by very strong intermolecular interactions proven by 1883 cm^?1 centred peak in FTIR spectrum.Thermal degradation of this new supramolecular compound is a two-step process in air. At first phthalic acid (47.4%) released up to 230°C, meanwhile it loses water and transforms into phthalic anhydride. In EGA-MS spectra, the characteristic fragments of water (m/z=17, 18) appear from about 180°C, while absorption bands of phthalic anhydride are shown in EGA-FTIR spectrum at about 210°C. In the second step theophylline begins to sublime, melts at 276°C, and then evaporates up to 315°C with minute residues.     

Ethanol Initiates Reactions Using Microwaves. A Technique for Aromatic Ester Synthesis

Orthophthalic monoesters were synthesized through a reaction between phthalic anhydride and potassium phenoxides. Synthesis was performed by irradiating pastes containing organic reagents and a small quantity of ethanol.     

Alkyd resins derived from glycolized waste poly(ethylene terephthalate)

In this investigation the production of secondary value-added products, such as alkyd resins, derived from the glycolysis of poly(ethylene terephthalate) (PET) is examined as an effective way for its recycling. PET was taken from common soft-drink bottles and diethylene glycol (DEG) was used for the depolymerization at several initial molar ratios. The oligomers obtained were analyzed according to their average molecular weights. Furthermore, the glycolyzed PET products (oligomers) were reacted with maleic anhydride, phthalic anhydride and propylene glycol to form unsaturated polyester resins. These were subsequently mixed with styrene and cured using the benzoyl peroxide/amine initiator system to carry out the reaction in ambient temperature. The curing characteristics of the resins produced were investigated with respect to the initial molar ratio of DEG/PET as well as the initial initiator concentration. Finally, the mechanical properties (tensile strength and elongation at the break point) of the resins were compared with the conventional general purpose resin and were found to be comparable.     

Thermally stable polymers based on bismaleimides containing amide,imide, and ester linkages

Seven new structurally different bismaleimides were synthesized and characterized by infrared and proton nuclear magnetic resonance spectroscopy. The chain of these polymer precursors was extended by incorporating amidized, imidized, and esterified 4-chloroformyl phthalic anhydride. The bismaleimides containing amide and imide linkages were prepared by a simple synthetic route based on the reaction of the monomaleamic acid derived from various aromatic diamines (1 mol) with 4-chloroformyl phthalic anhydride (0.5 mol) and subsequent cyclodehydration of the intermediate triamic acid. In addition, chain extended bismaleimides were prepared by reacting the monomaleamic acid derived from p-phenylenediamine with several dianhydrides such as p-phenylene bis(trimellitamide anhydride), p-phenylene bis(trimellitate anhydride), and bis-phenol A bis(trimellitate anhydride). The differential thermal analysis scans of bismaleimides showed exotherms at 221–304°C associated with their polymerization reactions. The thermogravimetric analysis traces of polymers did not show a weight loss up to 351–393 and 344–372°C in N₂ and air atmospheres, respectively. The anaerobic char yield of polymers at 800°C was 44–61%. These polymers can be used for fabrication of composites having improved properties.     

Chain extension of polyesters PET and PBT with two new diimidodiepoxides. II

Two new diglycidyl ester compounds containing preformed imide rings for better thermal stability were prepared to be used as chain extenders for PET and PBT. The preparation of these compounds was carried out in two steps. In the first step, diimidodiacids were prepared from pyromellitic anhydride and 3-aminopropanoic acid or 4-(aminomethyl)benzoic acid. From these diimidoacids, in a second step, diimidodiepoxides were obtained by reaction with epichlorohydrin. The aforementioned diimidodiepoxides were used as chain extenders for poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT) with satisfactory results. The polyester samples obtained from various residence times in the reactor, were characterized by solution viscosity measurements, carboxyl, and hydroxyl end-group determination. Starting from a PET having intrinsic viscosity ([η]) of 0.60 dL/g and carboxyl content (CC) of 42 equiv/10⁶ g, one could obtain PET with [η] of 1.16 and CC below 5 equiv/10⁶ g. The typical reaction condition for the coupling of PET was its heating with the chain extender under argon atmosphere above its melting temperature (280°C) for several minutes. Analogous results were obtained for PBT. The hydroxyl content in all cases was increased. © 1996 John Wiley & Sons, Inc.     

Chemical Modification of Polystyrene. VI. Thermal Stability Studies of Sulfonic Acid Resins from Anhydride Modified Polystyrene

Thermal stabilities of the H form of sulfonic acid resins from polystyrene electrophilically substituted with phthalic anhydride, pyro-mellitic dianhydride, trimellitic anhydride, and cis-1,2,3,6-tetra-hydrophthalic anhydride have been studied and compared by DTA and TGA. Isothermal degradation studies of these resins at 150 ± 10°C for 72 h in air and nitrogen reveal significant changes in IR, decreases in sulfur content, and increases in ion-exchange capacity values. The pH-metric titration characteristics of the pyro-mellitic-dianhydride-modified sulfonated polystyrene after isothermal heating under the above conditions indicate weak acid behavior, in contrast to the strong acid nature of the original resin.     

Adhesives and coatings based on phenolic/epoxy resins

Low molecular weight epoxy resin based on bis (4‐hydroxy phenyl) 1,1 cyclohexane was prepared and modified with various types of the prepared phenolic resins. Phenol–, cresol–, resorcinol–and salicylic acid–formaldehyde resins were used. The optimum conditions of formulation and curing process were studied to obtain modified wood adhesives characterized by high tensile shear strength values. This study indicated that the more suitable conditions are 1:2 weight ratio of phenol–or cresol–formaldehyde to epoxy resin in the presence of phthalic anhydride (20 wt%) of the resin content as a curing agent at 150°C for 80 min. Resorcinol–or salicylic acid–formaldehyde/epoxy resins formulated at 1:2 weight ratio were cured in the presence of paraformaldehyde (20 wt%) at 150°C for 60 min. The effect of the structure of phenolic resins on the tensile shear strength values of formulated resin samples, when mixed with the epoxy resins and cured under the previously mentioned optimum conditions for different times, was investigated. Metallic and glass coatings from the previous resins were also prepared and evaluated as varnishes or paints. Copyright © 1999 John Wiley & Sons, Ltd.     

Mechanism of phthalic anhydride formation in the oxidation of n-pentane on a vanadium-phosphorus oxide catalyst

The reaction paths of product formation in the partial oxidation of n-pentane on vanadium-phosphorus oxide (VPO) and VPO-Bi catalysts are considered. The condensed products of n-pentane oxidation were analyzed by chromatography-mass spectrometry, and the presence of C₄ rather than C₅ unsaturated hydrocarbons was detected. It was found that the concentration of phthalic anhydride in the products increased upon the addition of C₄ olefins and butadiene to the n-pentane-air reaction mixture. With the use of a system with two in-series reactors, it was found that the addition of butadiene to a flow of n-butane oxidation products (maleic anhydride, CO, and CO₂) resulted in the formation of phthalic anhydride. The oxidation of 1-butanol was studied, and butene and butadiene were found to be the primary products of reaction; at a higher temperature, maleic anhydride and then phthalic anhydride were formed. The experimental results supported the reaction scheme according to which the activation of n-pentane occurred with the elimination of a methyl group and the formation of C₄ unsaturated hydrocarbons. The oxidation of these latter led to the formation of maleic anhydride. The Diels-Alder reaction between maleic anhydride and C₄ unsaturated hydrocarbons is the main path of phthalic anhydride formation.