生物基2,5-呋喃二甲酸聚酯的研究进展

2,5-呋喃二甲酸聚酯是以生物质平台化合物2,5-呋喃二甲酸为主要单体的生物基聚酯。该文主要介绍2,5-呋喃二甲酸聚酯的研究进展,对2,5-呋喃二甲酸聚酯的性能、合成方法、合成用催化剂及其共聚改性研究进行对比分析和讨论。2,5-呋喃二甲酸聚酯的玻璃化转变温度、热稳定性、杨氏模量和抗拉强度与对苯二甲酸聚酯的相应性能接近。同时,2,5-呋喃二甲酸聚酯及其共聚物对CO_2、O_2和H_2O的阻隔性能优于对苯二甲酸聚酯,在许多领域是聚酯PET等材料的潜在替代物,受到了业界的广泛重视。然而,较低的断裂伸长率是2,5-呋喃二甲酸聚酯应用的瓶颈问题。共聚改性是改善2,5-呋喃二甲酸聚酯力学性能的有效方法之一,已有的共聚改性单体在改善2,5-呋喃二甲酸聚酯的断裂伸长率时使共聚物的杨氏模量和玻璃化转变温度大幅下降,合成具有较高断裂伸长率、较高杨氏模量和较高玻璃化转变温度的2,5-呋喃二甲酸聚合物是国内外学者亟待解决的难题,也是2,5-呋喃二甲酸聚酯共聚改性领域的重要研究方向。     

酯交换-熔融缩聚法合成PEF工艺及性能研究

以2,5-呋喃二甲酸二甲酯(DMFD)和乙二醇为原料,通过酯交换-熔融缩聚法合成了聚呋喃二甲酸乙二醇酯(PEF),研究了催化剂用量、酯交换温度及缩聚温度对反应速率的影响,利用红外(FTIR)和核磁(NMR)对合成的PEF结构进行了表征,并对合成的PEF进行了差示扫描量热(DSC)和热失重(TGA)测试.研究结果表明,酯...     

低色度2,5-呋喃二甲酸异辛酯的合成

采用酰氯法来制备低色度2,5-呋喃二甲酸异辛酯,首先是酰氯的制备,考察了酰化试剂、温度及时间对2,5-呋喃二甲酰氯产率的影响;然后制备2,5-呋喃二甲酸异辛酯,考察了催化剂对直接酯化法制备的2,5-呋喃二甲酸异辛酯色度的影响,温度、时间对酰氯法制备的2,5-呋喃二甲酸异辛酯产率的影响,并对两种方法制备的酯的色度进行了比较。结果表明,在90℃,1.5 h条件下,以固体光气为酰化试剂时,2,5-呋喃二甲酰氯产率最高为91.9%;采用直接酯化法制备的2,5-呋喃二甲酸异辛酯色度均大于500 APAH,而酰氯法制备的2,5-呋喃二甲酸异辛酯的色度为30~40 APAH,且在90℃,1 h条件下,产率最高为98.1%。与直接酯化法相比,酰氯法具有反应温度低、醇用量少、产品色度低等优点,具有良好的工业应用前景。     

生物基2,5-呋喃二甲酸(FDCA)及聚酯(PEF)的性能与应用

2,5-呋喃二甲酸(FDCA)是一种具有重要价值的生物基平台化合物,由FDCA制备的聚酯PEF具有与PET相比具有更为出众的力学和热性质,且阻气性能更好,被称为新一代的聚酯,生物基FDCA及其下游产品均显示出重要的应用价值,PEF被公认为生物塑料市场前途光明的一个新材料。综述了生物基2,5-呋喃二甲酸(FDCA)及聚酯(PEF)的性能特点与一些重要的用途,并对其开发前景做了展望。     

氯化亚铁催化合成呋喃-2,5-二甲酸及其二甲酯

以氯化亚铁为催化剂,呋喃、四氯化碳和甲醇回流反应10 h合成了呋喃-2,5-二甲酸二甲酯,产率97.5%;呋喃-2,5-二甲酸二甲酯经碱性条件下水解、酸化合成了呋喃-2,5-二甲酸,总产率90.7%。     

生物基PEF的合成及其等温结晶动力学研究

以生物基2,5-呋喃二甲酸二甲酯(DMFD)和乙二醇(EG)为原料,乙二醇锑为催化剂,利用酯交换法制备了生物基聚2,5-呋喃二甲酸乙二醇酯(PEF)。研究了生物基PEF的结构及热稳定性和结晶性能,应用等温结晶动力学研究了生物基PEF的结晶行为。结果表明:当DMFD与EG的摩尔比为1.8时,酯交换和缩聚反应最佳,核磁共振氢谱和傅里叶变换红外光谱测试结果表明合成的物质为目标产物PEF;生物基PEF具有与石油基聚对苯二甲酸乙二醇酯(PET)等聚酯相似的热稳定性,但其玻璃化转变温度(T_g)为90.7℃大于石油基PET的T_g,熔点(T_m)为211.6℃低于石油基PET的T_m;生物基PEF的等温结晶动力学研究表明,在150～170℃时,其Avrami指数为2.21～2.54,结晶度为20.8%～27.7%,结晶速率常数为(4.40～32.00)×10~(-3),表观活化能为43.98 kJ/mol,其中,165℃进行保温冷结晶时,生物基PEF结晶速率达到最大,但与石油基PET相比,生物基PEF结晶速率很慢。     

生物基2,5-呋喃二甲酸及其聚酯合成研究进展

如何通过高效、廉价的方法制备2,5–呋喃二甲酸(2,5-FDCA)及其聚合物已成为近几年的研究热点。重点介绍了2,5-FDCA的合成路线、聚2,5–呋喃二甲酸乙二醇酯(PEF)及其共聚酯的研究进展,并对其进行了分析。分析结果表明,目前2,5-FDCA的合成以5–羟甲基糠醛(HMF)氧化路线为主,其中催化剂采用贵金属,价格比较昂贵,建议对高效低价的新型催化剂体系进行开发。另外,为提高材料的各种性能,研究FDCA基聚酯改性的高性能产品,对经济、社会发展有着重大应用价值。     

2,5-呋喃二甲酸的研究进展及展望

本文介绍了生物质基平台研发的意义和2,5-呋喃二甲酸对整个一条产业链的带动作用。对国内外在该领域的研究情况与取得的成果、2,5-呋喃二甲酸制备路线的选择,以及2,5-呋喃二甲酸未来的发展趋势做了展望。     

宁波材料所在生物基PET合成方面取得新进展

正中科院宁波材料所朱锦研究员带领的生物基高分子材料团队通过以生物基芳香单体2,5-呋喃二甲酸与乙二醇共聚,采用熔融缩聚法,制备了一系列分子结构中呋喃环含量不同的生物基芳香聚酯——聚呋喃二甲酸乙二醇酯(PEF)(又称生物基PET),其特性黏数控制在0.75~0.98 d L/g之间。TGA和DSC研究表明,生物基芳香聚酯的Tg明显提高,PEF的Tg比PET提高了18℃,熔融温度降低了40℃,强度和模量提高了40%。材料气体阻隔性测试表明,PEF的CO2阻隔性比PET提高了14.8倍,O2阻隔性比PET提高了6.8倍。由于生物基芳香聚酯     

合成3,4-二取代呋喃-2,5-二甲酸的简便方法

报道了一种合成标题化合物的简便方法。在KOH的作用下,1,2-二羰基化合物二水合三聚乙二醛、草酸二乙酯或二苯乙二酮与二甘醇酸二甲酯在环己烷中回流6～8h,缩合成呋喃-2,5-二甲酸、3,4-二羟基呋喃-2,5-二甲酸和3,4-二苯基呋喃-2,5-二甲酸,产率为73.4%～98.6%。     

聚(2,5-二甲基对苯乙炔)前聚物的合成及表征

以对二甲苯为原料,经三步化学反应合成聚（２,５－二甲基－１,４－亚苯基－１′,２′－乙二撑－１′－氯化二乙锍盐）,讨论了温度、气氛和溶剂对聚合反应的影响。产品的结构由ＩＲ和１ＨＮＭＲ光谱得到确认     

Fully bio‐based polyesters derived from 2,5‐furandicarboxylic acid (2,5‐FDCA) and dodecanedioic acid (DDCA): From semicrystalline thermoplastic to amorphous elastomer

A serials of fully bio‐based poly(ethylene dodecanedioate‐2,5‐furandicarboxylate) (PEDF) were synthesized from Dodecanedioic acid (DDCA), 2,5‐Furandicarboxylic acid (2,5‐FDCA), and ethylene glycol through a two‐step procedure consisted of transesterification and polycondensation. After their chemical structures were confirmed by Nuclear Magnetic Resonance and Fourier Transform Infrared Spectroscopy, their thermal, mechanical, and biodegradation properties were investigated in detail. Results showed that the chemical composition of PEDFs could be easily controlled by the feeding mole ratio of DDCA to FDCA and they possessed the characteristic of random copolyester with the intrinsic viscosity ranged from 0.82 to 1.2 dL/g. With the varied mole ratio of DDCA to FDCA, PEDFs could be changed from semicrystalline thermoplastic to the completely amorphous elastomer, indicated by the elongation at break ranged from 4 for poly(ethylene 2,5‐furandicarboxylate) to 1500% for amorphous PEDF‐40. The amorphous PEDF‐30 and PEDF‐40 showed satisfactory shape recovery after cyclic tensile test, which was the typical behavior for elastomer. Enzymatic degradation test indicated that all the PEDFs were biodegradable and the degradation rate was heavily affected by their chemical compositions. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46076.     

Polymerizations of nitrogen-containing heterophanes by vapor deposition method,transformation to polymeric films bearing a conjugated structure,and their properties

Summary The polymerizations of three nitrogen-containing heterophanes such as [2.2](2,5)pyridinophane (1), [2.2](2,5)pyrazinophane (2) and N, N-dimethyl-[2.2](2,5)pyrrolophane (3) by the vapor deposition method were carried out. Compounds1, 2 and3 gave poly(2,5-pyridinediyl-ethylene), poly(2,5-pyrazinediylethylene), and poly(N-methyl-2,5-pyrrolediyl-ethylene) as tough films, respectively. The transformation of the ethylene unit in the polymer films to the vinylene one by the dehydrogenation reaction using 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) failed in the former two polymeric films and succeded to a certain extent in the latter one. The electrical conductivity of a poly(N-methyl-2,5-pyrrolediyl-vinylene) film obtained by the dehydrogenation reaction was measured to be 4×10^-4 S/cm at room temperature and increased up to 1×10^-2 S/cm on doping with iodine.     

Chemosynthesis and characterization of fully biomass‐based copolymers of ethylene glycol, 2,5‐furandicarboxylic acid,and succinic acid

Poly(ethylene 2,5‐furandicarboxylate‐co‐ethylene succinate) (PEFS) copolymers of 2,5‐furandicarboxylic acid (FDCA) and succinic acid with 11.98–91.32 mol % FDCA composition were synthesized via melt polycondensation in the presence of ethylene glycol using tetrabutyl titanate as a catalyst. PEFSs' molecular weight, thermal properties, and molar composition were determined by Fourier transform infrared spectroscopy, gel permeation chromatography, intrinsic viscosity, ¹H NMR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and wide‐angle X‐ray diffraction (WAXD) measurements. From experimental conditions, we obtained random copolymers with number‐average molecular weights exceeding 25,600, determined by GPC and ¹H NMR analyses. DSC analysis revealed that PEFS copolymers' melting temperatures differed depending on EF units' percentage. TGA studies confirmed that all PEFS copolymers' thermal stability exceeded 300°C. From WAXD analysis, it is observed that the PEFS copolymer crystal structure was similar to that of PES when EF unit was 11.98 mol % and to that of PEF when EF units were 74.35 and 91.32 mol %. These results benefit this novel biodegradable copolymer to be used as a potential biomaterial. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1415‐1420, 2013     

Biaxial Orientation of Poly(ethylene 2,5‐furandicarboxylate): An Explorative Study

The biaxial orientation behavior of poly(ethylene 2,5‐furandicarboxylate) (PEF) is studied in comparison to poly(ethylene terephthalate) (PET). PEF is a polyester that can be produced through similar steps as PET but using 100% biobased 2,5‐furandicarboxylic acid instead of terephthalic acid. This work highlights the stress–strain behavior of PEF during biaxial orientation at various temperatures. Strain hardening and strain‐induced crystallization in the oriented PEF samples generally appeared at higher stretch ratios for PEF than for PET at comparable molecular weight, while somewhat lower degrees of crystallinity are reached in PEF. Shrinkage in oriented PEF is found to be on par with PET in the region of the glass transition. Higher modulus and improved barrier properties, compared to PET, are found in the oriented materials when sufficiently high stretch ratios are applied in biaxial orientation.     

Aqueously soluble semi-aromatic copolyamides with dual-functional groups as sizing agent

A series of novel aqueously soluble semi-aromatic (co)polyamides, poly[(ethylenedioxy)bis(ethylene) terephthalamide]-ran-poly[(ethylenedioxy)bis(ethylene) (2,5-dihydroxy-3,6-diallyl)terephthalamide] (CRPAOT-x), were prepared via the solid-state Claisen rearrangement reaction of poly[(ethylenedioxy)bis(ethylene) terephthalamide]-ran-poly[(ethylenedioxy)bis(ethylene) 2,5-bis(allyloxy)terephthalamide] (APAOT-x), where x (= 0, 13, 25, 50, 75, and 100) represents the molar fraction of allyloxy containing unit. APAOT-x was obtained through the interfacial copolymerization of terephthaloyl chloride, 2,5-bis(allyloxy)terephthaloyl chloride, and 2,2′-(ethylenedioxy)bis(ethylamine). The reaction conditions including reactant concentration, temperature, and solvent were optimized. The chemical structures of the target (co)polyamides and their precursors were characterized by proton nuclear magnetic resonance (¹H NMR) and Fourier transform infrared spectroscopies. The incorporation of hydrophilic (ethylenedioxy)bis(ethylene) units greatly improved the polymer solubility. CRPAOT-x dissolved not only in polar organic solvents such as dimethylformamide, dimethyl sulfoxide, and N-methyl pyrrolidone but also in ammonia water. Due to the presence of hydroxyl groups and oxygen-rich aliphatic units, CRPAOT-x showed excellent affinity toward epoxy resins. The microbond test indicated that the aramid fibers sized by these dual-functional polymers exhibited remarkably enhanced interfacial shear strength in epoxy matrices. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47132.     

The effect of annealing on tensile properties of injection molded biopolyesters based on 2,5-furandicarboxylic acid

In this study, we investigate four polyesters based on 2,5-furandicarboxylic acid and different diols including 1,2-ethylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, and 1,6-hexylene glycol. Poly(ethylene 2,5-furanoate), poly(propylene 2,5-furanoate), poly(butylene 2,5-furanoate), and poly(hexylene 2,5-furanoate) (PHF) were characterized by thermogravimetric analysis, X-ray diffraction, differential scanning calorimeter, and tensile tests. In addition, the influence of annealing polyesters on their thermal and mechanical properties was investigated. For these reasons samples for the tensile test were prepared by injection molding. The tensile properties of injection molded samples were compared with samples that were additionally annealed after injection molding. All studied polyesters after heating treatment showed multiple melting behavior. The increase in the degree of crystallinity significantly influenced also the mechanical properties of the samples. It was found that the length of the aliphatic chain and degree of crystallinity plays a major role in the final properties of furan-based polyesters.     

Synthesis of conductive microspheres by radiation polymerization

A conductive monodisperse microspheres consisting of poly(ethylene glycol)dimethacrylate and methyloxycarbonyl-bicyclo[2.2.1]hepta-2,5-diene was synthesized by radiation induced polymerization. Ionic conductivity and relative dielectric constant were found to be greatly dependent on the content of poly(ethylene glycol)methacrylate in the copolymer. The diameter of the microspheres was 0.48-0.86 μm, in which the irradiation was carried out without stabilizer at a dose rate of 20 kGy/h with ⁶⁰Co γ-ray.     

Effect of the ionic conductivity of a polymer matrix on the electrooptical properties of polymer-dispersed liquid crystal films

Summary The influence of ionic conductivity on the electrooptical response was investigated. A new monomer of 2-(poly(ethylene glycol)oxycarbonyl)-bicyclo[2.2.1] hepta-2,5-diene (PEGOC-BCHD) was synthesized and polymerized. Polymer/liquid crystal composite films are composed of poly(PEGOC-BCHD), E8, and alkali metal salts. The ionic conductivities were measured as a function of the ratio of LiClO₄/ethylene oxide for various molecular weights of poly(ethylene glycol). The results indicate that the threshold field and response rise time can be reduced by increasing ionic conductivity of the matrix polymer. Liquid crystal droplets were observed in a continuous matrix phase in the form of ‘Swiss cheese’ morphology. Received: 13 March 1998/Accepted: 19 May 1998