Characterization and thermal stability of PMR polyimides using 7-oxa-bicyclo[2,2,1]hept-5-ene-2, 3-dicarboxylic anhydride as end caps

An anhydride monomer containing ether oxide bridge,7-oxa-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic anhydride (ONA),was successfully synthesized by Diels-Alder reaction of furan and maleic anhydride.The ONA was also studied as an end-cap for the polymerization of monomer reactant(PMR) type polyimides.Three molecular weight levels of the ONA end-capped PMR resins were evaluated.The effects of process conditions of these novel PMR resins on thermal and mechanical properties were investigated.It was demonstrated that the imidized prepolymers using the end-cap have good processability,and the cured polyimide specimens exhibited good thermal stability.The initial decomposition temperature, T_d(ca.580℃) and glass transition temperature,T_g(330℃) of the novel resin(PI-20),prepared under optimum process conditions,compare favorably with the T_d(ca.620℃) and T_g(ca.348℃) of the state-of-the-art resin(PI’-20),respectively.     

含三氟甲基聚酰亚胺的合成与性能研究

通过在4,4′-二氨基二苯醚(4,4-′ODA)单体中引入三氟甲基合成了一种新型二胺单体2-三氟甲基-4,4′-二氨基二苯醚(3FODA),该单体具有良好的溶解性和高的反应活性,使用3FODA替代4,4′-二氨基二苯甲烷(MDA)制备了PMR热固性聚酰亚胺树脂.树脂溶液高浓度低粘度,具有室温下良好的储存稳定性;树脂具有很好的加工性能,成型后的模压件显示了优异的热性能和耐热氧化稳定性,玻璃化转变温度在336~379℃之间;此外树脂具有较好的电性能和较低的吸水率.     

Characterization of novolac resins based on p-tert-butylphenol by PMR spectroscopy

The direct silylation of tert-butylphenol formaldehyde resins with N,O-bis(trimethylsily)acetamide (BSA) has allowed a more complete analysis of these resins to be made with proton magnetic resonance (PMR) spectrometry. A quantitative determination of mixtures of the monomer, dimer, trimer, and tetramer may be carried out at 100 MHz.     

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     

Chain extension of ketonic resins

Chain extensions of cyclohexanone-formaldehyde (CF) and acetophenone-formaldehyde (AF) resins via their hydroxyl groups were studied. The chain extension was regulated by the ratio of hydroxyl groups/reactive reagents. Dimethyl dichlorosilane, phosphorus oxychloride, toluene-2, 4-diisocyanate, phthalic anhydride, tetrahydro phthalic anhydride, trimellitic anhydride, 4, 4'-oxydiphthalic anhydride were used as chain extender reagent. It has been shown that solubilites, melting point and molecular weight of extended resins depended upon the characteristics of chain extender reagents.     

含氟苯乙炔苯胺封端聚酰亚胺的合成与性能研究

设计并合成了一种含氟苯乙炔苯胺封端剂4-苯乙炔基-3-三氟甲基苯胺(3FPA),使用3FPA与4,4′-(六氟异丙基)双邻苯二甲酸二酐(6FDA)和对苯二胺(p-PDA)制备了计算分子量为5000的聚酰亚胺树脂3FPA-PI-50,并对树脂溶液、树脂模塑粉和树脂模压件的制备与性能进行了研究,实验结果表明3FPA-PI-50树脂溶液具有良好的储存稳定性,成型后树脂具有优异的热性能和热氧化稳定性,后固化后树脂玻璃化转变温度为404℃,5%热失重温度大于530℃.此外树脂具有低的介电常数和吸水率.     

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.     

Investigation of the stereochemistry of adducts of aryloxyfurans with maleic acid derivatives by PMR spectroscopy

The stereochemistry of adducts of aryloxyfurans with maleic acid derivatives was studied by PMR spectroscopy. It was shown that adducts with maleic anhydride are produced only in the form of exo isomers, whereas adducts with N-phenyl-maleinimide are isolated from the reaction in the form of mixtures of endo and exo forms. Bromination of the adducts was realized. The orientation of the bromine atoms in the bromination products was established by PMR spectroscopy: The bromine atoms in the dibromo derivative of the adduct with maleic anhydride are cis-oriented (endo-4-Br, endo-5-Br), whereas the bromine atoms have a trans configuration (endo-4-Br, exo-5-Br) in the dibromo derivative of the adduct with N-phenylmaleinimide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 613–615, May, 1984.     

Thermal behaviour of cardanol-based benzoxazines

A novel benzoxazine monomer (Bz-C) based on agrochemical renewable resource—cardanol (by-product of cashew nut tree, Anacardium occidentale) was synthesized. Bz-C, a liquid monomer, was used as reactive diluent for the solventless synthesis of bisphenol-A benzoxazine monomer (Bz-A). Benzoxazine monomer based on cardanol and bisphenol-A in 3:1, 1:1 and 1:3 blend ratio were prepared by this method. The resins had Brookfield viscosity at 316 K in the range of 145–81,533 mPa s. The resins were characterized by ¹H-NMR, FTIR and elemental analysis. Curing characteristics were studied by DSC analysis. Thermal stability of cured resins was found to improve with increase in Bz-C content in the blends.     

Perspective thermally stable thermoset binders for polymer composite materials

Brief review of the modern state in the field of thermally stable thermoset resins used as binders for engineering polymer composites in presented. Synthesis, processing, properties, and application of such materials are discussed. The list of binders includes polyimide PMR resins, oligoimides with reactive end groups, bismaleimides, and phthalonitrile resins.     

Étude de la compatibilité d'un système polyamide/phase caoutchoutique modifiée par l'anhydride maléique—I. Étude de la modification de la phase caoutchoutique par l'anhydride maléique

The study deals with the variation of physical properties of a blend (50/50 polyethylene/terpolymer ethylene-propylene-diene monomer) due to chemical modification by maleic anhydride. This compound is generally used as a rubbery domain in polyamide resins. The chemical modification induces cross-linking the amount of which is clearly revealed by the variation of the elastic modulus and the residual deformation of the samples. The crystallization ratio of the polyethylene, measured by differential scanning calorimetry, is also related to the chemical modification. This effect may be due to an increase in the miscibility of the two constituents of the blend.     

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.     

Studies on the curing kinetics of epoxy resins using mixture of nadic/or maleic anhydride and 4,4′-diaminodiphenyl sulfone

Curing kinetics of diglycidyl ether of bisphenol-A (DGEBA) in the presence of maleic anhydride (MA)/or nadic anhydride (NA) or mixture of MA/NA: 4,4′-diaminodiphenyl sulfone (DDS) in varying molar ratios were investigated using differential scanning calorimetry. Curing behaviour of DGEBA in the presence of varying amounts of DDS:MA/NA was evaluated by recording DSC scans at heating rates of 5, 10, 15 and 20°C min⁻¹. The peak exotherm temperature depends on the heating rate, structure of the anhydride as well as on the ratio of anhydride: DDS. Thermal stability of the isothermally cured resins was evaluated by thermogravimetry. The char yield was highest in case of resins cured using mixture of DDS:MA (0.75:0.25; sample EM-1) and DDS:NA (0.75:0.25, sample EN-1).     

Phosphorus-containing imide resins. III

Three imide monomers were prepared by reacting maleic anhydride; 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride, bis(m-aminophenyl) methyl phosphine oxide, and tris(m-aminophenyl) methyl phosphine oxide, and tris (m-aminophenyl) phosphine oxide. The characterization was done by elemental analysis and infrared spectroscopy (IR). These monomers were soluble in acetone. Their thermal polymerization was investigated by differential scanning calorimetry (DSC). The temperature of the exothermic peak position was influenced by the presence of free amino group in the monomer and was about 50°C higher in monomers that did not contain amino group. Anaerobic char yield of imide monomers cured at 270 ± 2°C for 30 min ranged from 58 to 64%. Graphite cloth laminate fabricated from one of these resins had a limiting oxygen index of 100.     

适用于RTM成型聚酰亚胺材料研究进展

综述了适用于RTM成型耐高温聚酰亚胺材料的研究进展，主要包括降冰片烯酸酐（NA）封端的PMR聚酰亚胺树脂和使用苯乙炔基封端剂合成的酰亚胺低聚物，在这其中采用苯乙炔基封端剂合成的酰亚胺低聚物具有低的熔体粘度和良好的熔体稳定性，固化交联后的聚合物及树脂基复合材料具有良好的热性能和力学性能。本文介绍了上述聚合物化学合成、结构与性能之间的关系，并对适用于RTM成型耐高温聚酰亚胺材料的应用进行了简单介绍。     

SYNTHESES AND ADSORPTION PROPERTIES OF PHENOL-FORMALDEHYDE-TYPE CHELATING RESINS BEARING THE FUNCTIONAL GROUP OF TARTARIC ACID

Several kinds of novel chelating resins bearing the functional group of tartaric acid (TTA-FQ-12, TTA-FQ-23, and TTA-FQ-34) were synthesized by reacting epoxy maleic anhydride, which was prepared through the oxidization reaction of maleic anhydride by hydrogen peroxide, with phenol-formaldehyde resin containing polyamine (FQ resins series). The effects of such factors as reaction time, reaction temperature and pH value on the loading capacity of TTA in resins were investigated. The results showed that the optimum reaction conditions are as follows: time 9-12h; temperature 90-105℃;pH value 6-10. The loading capacities of TTA can reach 0.15, 0.14, and 0.11 mmol/g^-1 when the functional group of FQ resin was -OCH2CH2NHC2H4NH2, -O(CH2CH2NH)2C2H4NH2 and -O(CH2CH2NH)3C2H4NH2), respectively. The structures of resins were characterized by FTIR spectra. The primary study on the adsorption properties of the resins for metal ions showed that there are two kinds of adsorption mechanisms i.e. ion exchange and chelate in the adsorption process. TTA-FQ resins have much higher adsorption selectivity for Pb^2 and Zn^2 than for Cu^2 and Ni^2 . These resins can probably be used for separating Pb^2 or Zn^2 in the mixture of metal ions or for treating wastewater containing heavy metal ions.     

Structural features of <Emphasis Type="Italic">N</Emphasis>-acylcytisines

N-Acyl cytisine derivatives were synthesized by acylation with acetic anhydride; benzoyl and o-bromo- and p-nitrobenzoyl chlorides; and crotonyl and cinnamoyl chlorides. The structures of the synthesized compounds were studied using IR, PMR, and x-ray structure analysis (XSA). PMR spectra of the N-acylcytisines in solution typically had two rotational isomers around the N12–CO bond. Conformational analysis was performed using XSA for the position of the acyl group relative to the cytisine core. Bond lengths and angles of the acyl groups involved in the conjugation were analyzed.     

A sol–gel polymerization method for creating nanoporous polyimide silsesquioxane nanostructures as soft dielectric materials

A sol–gel polymerization method was developed to make polyimide (PI) silsesquioxane (SSQ) nanoparticles as functional, soft dielectric materials. The surface functionalization of the polymer chain backbone and chain ends of poly(trimellitic anhydride chloride‐co‐4,4′‐methylenedianiline), PMR‐15 resin, with para‐(chloromethyl)‐phenylethyltrimethoxy silane yielded a novel sol–gel reactive sites functionalized PMR‐silane precursor. Upon base‐catalyzed hydrolysis and condensation of the PMR‐silane precursor, spherical, raspberry‐like PMR‐SSQ nanoparticles were obtained in considerably good yield. Controlling the particle size distribution was attempted upon adjusting the molar ratio between the silane precursor and the base, as well as in the presence of a catalytic amount of silica sols. Particle composition, thermal stability, and morphology were confirmed from Fourier transform infrared, thermogravimetric analysis, and scanning electron microscopy analyses. Nanoparticles, visualized under transmission electron microscopy exhibit a nanoporous structure. The Brunauer–Emmett–Teller analysis confirmed that the average pore dimension is ranged from 2 to 5 nm. The dielectric constant of PMR‐SSQ nanoparticles was as low as 1.95, compared to dielectric constants of 3.05 and 3.13 for PMR‐15 and PMR‐silane, respectively. Thus, the base‐catalyzed sol–gel polymerization of alkoxysilylated PI offers a novel synthetic path to make functional nanoporous PI nanostructures that possess ultralow dielectric constants. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 57, 562–571.     

低相对分子质量苯乙烯-马来酸酐交替共聚物的合成

将引发剂偶氮二异丁腈(AIBN)、共聚单体苯乙烯(St)和马来酸酐(MA)溶解于甲苯中,采用沉淀聚合法合成苯乙烯-马来酸酐共聚物(SMA).分别研究了反应温度、引发剂用量、反应时间、单体配比和单体浓度对聚合物得率和酸酐含量的影响.采用正交实验确定最优反应条件为:单体浓度20%,单体物质的量比为1∶1,引发剂用量为0.60%,反应温度为86℃,反应时间2h,产物得率为86.86%,酸酐含量为50.28%.并利用傅里叶变换红外光谱(FTIR)、核磁共振碳谱(~(13)C NMR)、凝胶渗透色谱(GPC)和热分析法分别研究聚合物的分子结构、相对分子质量及相对分子质量分布和热稳定性.结果表明产物是苯乙烯-马来酸酐交替共聚物,相对分子质量分布较窄,具有良好的热稳定性.     

193 nm深紫外光刻胶用成膜树脂的研究进展

本文综述了用于193 nm深紫外光刻胶的主体成膜树脂的种类及常用合成单体的研究进展,包括聚(甲基)丙烯酸酯体系、环烯烃-马来酸酐共聚物(COMA)体系、乙烯醚-马来酸酐共聚物(VEMA)体系、降冰片烯加成聚合物体系、环化聚合物体系、有机-无机杂化树脂体系以及光致产酸剂(PAG)接枝聚合物主链型等,并分析了目前关于曝光、分辨率和抗蚀刻性能方面存在的问题及未来的发展方向。