Aliphatic Dianhydride Research Articles

Synthesis of an Aliphatic Dianhydride Monomer and Its Colourless, Low Dielectric Constant Aliphatic Polyimides

Synthesis of an Aliphatic Dianhydride Monomer and Its Colourless, Low Dielectric Constant Aliphatic Polyimides

Dynamic Aliphatic Polyester Elastomers Crosslinked with Aliphatic Dianhydrides.

Chemically crosslinked elastomers are a class of polymeric materials with properties that render them useful as adhesives, sealants, and in other engineering applications. Poly(γ-methyl-ε-caprolactone) (PγMCL) is a hydrolytically degradable and compostable aliphatic polyester that can be biosourced and exhibits competitive mechanical properties to traditional elastomers when chemically crosslinked. A typical limitation of chemically crosslinked elastomers is that they cannot be reprocessed; however, the incorporation of dynamic covalent bonds can allow for bonds to reversibly break and reform under an external stimulus, usually heat. In this work, we study the dynamic behavior and mechanical properties of PγMCL elastomers synthesized from aliphatic dianhydride crosslinkers. The crosslinked elastomers in this work were synthesized using the commercially available crosslinkers, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride and three-arm hydroxy-telechelic PγMCL star polymers. Stress relaxation experiments on the crosslinked networks showed an Arrhenius dependence of viscosity with temperature with an activation energy of 118 ± 8 kJ/mol, which agrees well with the activation energy of transesterification exchange chemistry obtained from small molecule model studies. Dynamic mechanical thermal analysis and rheological experiments confirmed the dynamic nature of the networks and provided insight into the mechanism of exchange (i.e., associative or dissociative). Tensile testing showed that these materials can exhibit high strains at break and low Young's moduli, characteristic of soft and strong elastomers. By controlling the exchange chemistry and understanding the effect of macromolecular structure on mechanical properties, we prepared the high-performance elastomers that can be potentially reprocessed at moderately elevated temperatures.

Flexible thin films based on poly(ester imide) materials for optoelectronic applications

AbstractA series of high‐performance poly(ester imide)s bearing cycloaliphatic moieties was manufactured by a two‐step procedure via solution polycondensation of an aromatic–aliphatic dianhydride containing preformed ester units and cyclohexanone ring in the main chain, with various aromatic diamines. The new dianhydride monomer, namely 2‐oxocyclohexane‐1,3‐bis[4,4′‐bis(trimellitate)benzylidene] dianhydride, was synthesized by the reaction between 2,6‐bis(4‐hydroxybenzylidene)cyclohexanone and trimellitic anhydride chloride. The chemical structure of the resulting dianhydride was confirmed by means of Fourier transform infrared, 1H NMR and 13C NMR spectroscopies. The poly(ester imide)s from the series exhibited water uptake capacity in the range 3.45–10.09%. The onset temperatures, corresponding to the first detected thermal weight loss in the samples, ranged from 367 to 441 °C. Besides the cycloaliphatic moieties coming from the dianhydride monomer, the other aliphatic segments present in the diamine structures were responsible for improved optical performance in the resulting poly(ester imide)s, the transmittance being higher than 80% at 684 nm. © 2021 Society of Industrial Chemistry.

Synthesis of highly transparent and thermally stable copolyimide with fluorine‐containing dianhydride and alicyclic dianhydride

ABSTRACTThe development of optical films is highly desirable for applications in flexible displayers. In this work, a copolyimide (co‐PI) film with high thermal stability and high transparency was prepared by the copolymerization of 2,2′‐bis(trifluoromethyl)‐4,4′‐diaminodiphenyl ether, cyclobutanetetracarboxylic dianhydride, and 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA). The effects of aliphatic dianhydride and fluorine dianhydride monomers on the optical, thermal, and mechanical properties of the co‐PIs were discussed in detail based on the experimental results and theoretical simulations. We found that the preparation of polyimide (PI) based on the combination of two dianhydrides could obtain the PI film with excellent comprehensive performance due to nonconjugated structure and strong electron‐withdrawing effect. Through the structure and composition optimization, a PI film of PI‐6FDA‐70 with Tg of 300 °C, Td10% more than 500 °C, the average transparency of 90% and the elongation at the breakage more than 8% was prepared. Such molecular design provides a practical approach to develop high‐performance colorless PI films. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48603.

Thermal, combustion and optical properties of new polyimide/ODA-functionalized Fe3O4 nanocomposites containing xanthene and amide groups

A new soluble polyimide was successfully synthesized via direct poly-condensation reaction between aromatic diamine containing xanthene group and aliphatic dianhydride. Multifunctional polyimide including xanthene derivatives, amide groups and high content of aromatic rings as well as aliphatic linkages was designed and synthesized. The polyimide was characterized by size exclusion chromatography, Fourier transform infrared spectroscopy and nuclear magnetic resonance (1H NMR). Fe3O4 nanoparticles were functionalized by 4,4′-oxydianiline (ODA). Polyimide/Fe3O4 nanocomposites were prepared by covalently embedding the ODA-functionalized Fe3O4 (ODA-Fe3O4) containing amine groups (5 and 8 mass% of the nanoparticle). This functionality not only gave specific characteristics to Fe3O4 nanoparticles but also improved the interphase interaction between the nanoparticles and the polyimide matrix through covalent attachment. For comparison, nanocomposites using unmodified Fe3O4 nanoparticles also were prepared. The TEM analysis showed better dispersion of ODA-Fe3O4 within the polyimide matrix, which arising from formation of covalent bonding between ODA-functionalized Fe3O4 and the polyimide chains. Moreover, magnetic, optical, combustion and thermal properties of the polyimide and the corresponding nanocomposites were studied. Thermo gravimetric analysis results indicated improving on thermal properties of the polyimide nanocomposites as compared with the neat polyimide. According to microscale combustion calorimetry (MCC) analysis, 73.5% reduction in the peak heat release rate value was achieved by introducing 8 mass% of ODA-Fe3O4 in the polyimide matrix. Moreover, MCC analysis showed that ODA-Fe3O4 have better efficiency on improving the flame retardancy of the polyimide as compare with unmodified Fe3O4 nanoparticles.

Semi‐aromatic polyimide/Ag nanocomposite derived from vanillin

ABSTRACTThe development of bioprecursor polyimide/Ag nanocomposites (PI/Ag NCs) is reported in this investigation. Semiaromatic bioprecursor PI was successfully synthesized through direct polycondensation reaction between aromatic diamine containing pyridine ring and aliphatic dianhydride. Aromatic diamine as a monomer was synthesized using a renewable resource, vanillin. The main attractive aspects of this PI are the renewable origin of the diamine, presence of pyridine and high aromatic rings content, as well as aliphatic content on the polymer backbone. The structure of synthesized monomer and PI were proven by FTIR, and nuclear magnetic resonance. The PI/Ag NCs containing 3, 5, and 7 wt % of Ag nanoparticles (Ag NPs) were prepared through solution technique and the resulting NCs were characterized by Fourier transform infrared spectra, wide angle X‐ray diffraction, transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). TEM results showed that the Ag NPs were dispersed homogeneously in the PI matrix on nanoscale. TGA results indicated improving in thermal properties of PI/Ag NCs compared to the neat PI due to the interaction between the PI matrix and the Ag NPs. Antibacterial activity of PI/Ag NCs was tested by the disk diffusion method using Escherichia coli as model strain of gram‐negative bacteria. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44001.

Poly(ethylene glycol) derivatives containing periodic side-chain carboxyl groups: synthesis and characterization

The aim was the synthesis of chain-extended poly(ethylene glycol) (PEG) derivatives containing periodic side-chain carboxyl groups. The chain extension of PEG diols with pyromellitic dianhydride was performed in toluene or dimethylformamide solution and in bulk. The degree of chain extension (DoCE) was between 6 and 21, the highest value being recorded when the reaction was performed using low-molecular-weight PEG. The recorded limited increase of molecular weight could be at least partially attributed to the rather low reactivity of the aromatic dianhydride. To overcome this issue, a more reactive aliphatic dianhydride, ethylenediaminetetraacetic dianhydride (EA), was tested. However, the reaction of PEG with EA only afforded a DoCE of 2.5. Appreciably higher DoCE values were obtained when EA was reacted with bisamino-terminated PEG. Independent of prepolymer and dianhydride structure, all chain-extended products displayed less of a tendency to crystallization than the starting prepolymer, very likely due to interference by anhydride residues. The low in vitro cytotoxicity of the chain-extended polymers and the presence of carboxyl groups point to their possible use in biomedical applications, particularly in controlled drug release and tissue engineering. © 2014 Society of Chemical Industry

Synthesis and characterization of fully aliphatic polyimides from an aliphatic dianhydride with piperazine spacer for enhanced solubility, transparency, and low dielectric constant

A new series of fully aliphatic polyimide (API) based on a novel aliphatic dianhydride monomer-2,20-(1,4-piperazinediyl)-disuccinic anhydride (PDA), in which two units of succinic anhydride have been connected by an aliphatic heterocyclic piperazine spacer that possesses aminomethylene (-NCH2) moiety in the aliphatic/alicylic backbone capable of inducing charge transfer (CT) interactions in the polyimide network, was successfully synthesized. The APIs were soluble in common polar organic solvents. The polyimide films of PDA with alicyclic diamines were almost colorless. T10 (temperature of 10% weight loss) of APIs were ranged from 299–418 C and Tg of API3-API6 were in the temperature range of 170 to 237 C. The light-colored polyimide films of API3-API6 possessed good mechanical properties with tensile strength of 54–72 Mpa, tensile modulus of 1.6–2.3 Gpa and elongation at break of 4–9%. The polyimide films of API3-API6 were highly flexible and freestanding which is quite rare in fully APIs. The dielectric constant of one of the synthesized API (API4) was as low as 2.14. VC 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 00, 000–000

Synthesis and Characterization of Organosoluble Polysiloxaneimides Derived from Siloxane-containing Aliphatic Dianhydride and Various Aromatic Diamines

A new siloxane-containing monomer, 5,51- exo-(1,1,3,3,5,5-hexamethyl-trisiloxane -1,5-diyl) bisbicyclo[2,2,1]heptene-2,3- endo-dicarboxylic anhydride (3) was synthesized by the hydrosilylation reaction of 1,1,3,3,5,5-hexamethyl-trisiloxane (1) and cis-5-norbornene- endo-2,3-dicarboxylic anhydride (2). A series of organosoluble polysiloxaneimides (PI 5a-e) was prepared from the dianhydride 3 and several aromatic diamines 4 by a one-step high-temperature polycondensation method and the structures were characterized by IR and NMR. The effects of the main chain siloxane groups on the properties of PIs were evaluated by solubility, thermal stability and dielectric properties in addition to optical and water adsorption. The PIs were readily soluble in polar aprotic solvents such as NMP, DMAc and CHCl 3 at room temperature, except PI 5a, which was only soluble in polar amide type solvents at elevated temperature. PIs 5a-e had glass transition temperatures between 138 and 251°C in N2 and the 5% weight loss temperature ranged from 460 to 470°C under air. The PIs could be cast into flexible and tough films from DMAc solution. The films had tensile strengths of 44—52 MPa, tensile moduli of 0.56—0.68 GPa and elongations at break from 5.8—7.9%. The PI films exhibited good optical UV-vis transparency with wavelength cutoff of 269—289 nm and transmittances over 90% at 400 nm, and dielectric constants of about 2.76—2.65 with low water adsorption (0.3—0.4%).

Novel high-Tg poly(amine-imide)s bearing pendent N-phenylcarbazole units: synthesis and photophysical, electrochemical and electrochromic properties

A new carbazole-derived, triphenylamine-containing aromatic diamine monomer, 4,4′-diamino-4″-N-carbazolyltriphenylamine, was successfully synthesized by the caesium fluoride-mediated condensation of N-(4-aminophenyl)carbazole with 4-fluoronitrobenzene, followed by palladium-catalyzed hydrazine reduction. A series of novel poly(amine-imide)s 6a–6g with pendent N-phenylcarbazole units having inherent viscosities of 0.17–0.56 dL g−1 were prepared from the newly synthesized diamine monomer and seven commercially available tetracarboxylic dianhydrides via a conventional two-step procedure that included a ring-opening polyaddition to give polyamic acids, followed by chemical or thermal cyclodehydration. The polymers of the series were amorphous and most of them could afford flexible, transparent, and tough films with good mechanical properties. All the poly(amine-imide)s had useful levels of thermal stability associated with high glass-transition temperatures (303–371 °C), 10% weight-loss temperatures in excess of 543 °C, and char yields at 800 °C in nitrogen higher than 60%. The poly(amine-imide)s 6e–6g exhibited a UV-vis absorption maximum at around 300 nm in NMP solution. The poly(amine-imide) 6g derived from an aliphatic dianhydride was optically transparent in the visible region and fluoresced violet–blue at 403 nm in NMP with 4.54% quantum yield higher than the wholly aromatic 6e and 6f. The hole-transporting and electrochromic properties were examined by electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the poly(amine-imide) films on an indium-tin oxide (ITO)-coated glass substrate exhibited a reversible oxidation wave at 1.05 V and an additional irreversible oxidation wave at 1.39 V versus Ag/AgCl in acetonitrile solution. The polymer films revealed excellent stability of electrochromic characteristics, with a color change from neutral pale yellowish to green doped form at applied potentials ranging from 0.00 to 1.15 V.

Synthesis of aliphatic-aromatic polyimides by two-step polymerization of aliphatic dianhydride and aromatic diamine

Aliphatic-aromatic polyimides were synthesized by polycondensation reaction in solvent. The effects of variables such as the kind of solvent, reaction time and temperature, and monomer concentration were investigated in detail on the reaction of 1,2,3,4-butanetetra-carboxylic dianhydride and 4,4′-diaminodiphenylmethane. The viscos-ities of polyimides were between 0.22 and 0.46 dL/g. The polyimides were soluble in some aprotic polar solvents, such as N,N′-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), dimethylsulfoxide (DMSO), and N,N′-dimethylformamide (DMF). They began to decompose at 380–410°C in air, and 10% weight loss temperatures were 430–450°C. © 1996 John Wiley & Sons, Inc.