Two carborane-containing resol phenolic resins（P1 and P2） with high boron content were synthesized via the reaction of carborane bisphenols（1 and 2） with formaldehyde in the presence of alkaline. HRMS results indi...Two carborane-containing resol phenolic resins（P1 and P2） with high boron content were synthesized via the reaction of carborane bisphenols（1 and 2） with formaldehyde in the presence of alkaline. HRMS results indicate that P1 is mainly composed of hydroxymethylated o-carborane bisphenols, the Mw of which was restrained around 500 due to the strong steric hindrance of o-carborane bisphenol. In contrast, the molecular weight of P2 was well regulated under various reaction conditions. The obtained resins were characterized with spectroscopic techniques including FTIR, 1H-NMR, ^13C-NMR, and 11B-NMR, which gave satisfactory results. TGA studies show that P2 shows char yield of 88.9% and 92.9% at 900 ℃ under nitrogen and air respectively. The imported carborane cage endows phenolic resin with ultrahigh char yield. Particularly, the char yield of the obtained carborane-containing phenolic resin under air is higher than that under nitrogen. FTIR and XRD confirm that the carborane cage could react with oxygen to form B2O3 at elevated temperatures, which postpones the thermal decomposition of phenolic resin and accounts for the high char yield.展开更多
This article describes the synthesis of a series of aromatic amide-amines and their potential use as epoxy hardeners. These amines were synthesized by the reaction of L-phenylalanine （PA） with diamines of different ...This article describes the synthesis of a series of aromatic amide-amines and their potential use as epoxy hardeners. These amines were synthesized by the reaction of L-phenylalanine （PA） with diamines of different structures i.e. 1,4- phenylene diamine （PD）, 1,5-diamino naphthalene （N）, 4,4＇-（9-fluorenyllidene）-dianiline （F）, 4,4＇-diaminodiphenyl sulphide （DS） and 3,4＇-oxydianiline （O） in a stoichiometric ratio （I ：1）. Structural characterization of synthesized amide-amines was done with the help of elemental analysis and spectroscopic techniques viz. FT-IR, 1H-NMR and 13C-NMR. An epoxy blend was prepared by mixing tris（glycidyloxy） phosphine oxide （TGPO） with conventional epoxy i.e. diglycidyl ether of bisphenol-A （DGEBA） in an equivalent ratio of 2：3 to incorporate phosphorous into the main chain. The curing kinetics of the epoxy blend with synthesized aromatic amide-amines was investigated by non-isothermal DSC technique using multiple heating rate method （5, 10, 15 and 20 K/min.）. The activation energies were determined by fitting the experimental data into Kissinger and Ozawa kinetic models. The activation energies obtained through Ozawa method were slightly higher than those of Kissinger method but were comparable. However, both the energies were found to be dependent on the structure of amines. The thermal stability and weight loss behavior of isothermally cured thermosets were also investigated using thermogravimetric analysis （TGA） in nitrogen atmosphere. All the samples showed improved thermal stability in terms of char yield than using only amines as hardeners.展开更多
The curing behavior of diglycidyl ether of bisphenol-A(DGEBA) with aromatic diamide-diimide-diamines having aryl ether,sulfone and methylene linkages was studied by differential scanning calorimetry(DSC).Nine diamide-...The curing behavior of diglycidyl ether of bisphenol-A(DGEBA) with aromatic diamide-diimide-diamines having aryl ether,sulfone and methylene linkages was studied by differential scanning calorimetry(DSC).Nine diamide-diimide-diamines of varying structure were synthesized by reacting 1 mole of dianhydride with 2 moles of L-cysteine(S) in a mixture of acetic acid and pyridine(3:2 V/V) followed by activation with thionyl chloride(SOCl_2) and then condensation with excess of diamines.Structural characterization...展开更多
A novel epoxy-imide resin based on diglycidyl ether of bisphenol-A and N-（4-hydroxyphenyl）terahydrophthalic anhydrideimide（HTAM） was synthesized. The structural characterization of the epoxy-imide resin was conduc...A novel epoxy-imide resin based on diglycidyl ether of bisphenol-A and N-（4-hydroxyphenyl）terahydrophthalic anhydrideimide（HTAM） was synthesized. The structural characterization of the epoxy-imide resin was conducted by FT-IR spectra. 4,4＇-diaminodiphneylmethane（DDM） was used as a curing agent for the epoxy-imide resin. The thermal properties of the cured resin were evaluated with dynamic mechanical analyses（DMA） and thermogravimetric analysis（TGA）. The results showed that the cured resin exhibited a high glass transition temperature（Tg） of 186 ℃ when the molar amount of HTAM was 0.04 mol in the resin. The yields of the cured resin at 800 ℃ raised from 16.45% to 19.41%. The flexural properties were also measured, the flexural strength raised from 79.4 to 95.7 MPa, and the flexural modulus exhibited from 2.6 to 3.0 GPa.展开更多
基金financially supported by the Fundamental Research Funds for the Central Universities(No.JD-1512)
文摘Two carborane-containing resol phenolic resins（P1 and P2） with high boron content were synthesized via the reaction of carborane bisphenols（1 and 2） with formaldehyde in the presence of alkaline. HRMS results indicate that P1 is mainly composed of hydroxymethylated o-carborane bisphenols, the Mw of which was restrained around 500 due to the strong steric hindrance of o-carborane bisphenol. In contrast, the molecular weight of P2 was well regulated under various reaction conditions. The obtained resins were characterized with spectroscopic techniques including FTIR, 1H-NMR, ^13C-NMR, and 11B-NMR, which gave satisfactory results. TGA studies show that P2 shows char yield of 88.9% and 92.9% at 900 ℃ under nitrogen and air respectively. The imported carborane cage endows phenolic resin with ultrahigh char yield. Particularly, the char yield of the obtained carborane-containing phenolic resin under air is higher than that under nitrogen. FTIR and XRD confirm that the carborane cage could react with oxygen to form B2O3 at elevated temperatures, which postpones the thermal decomposition of phenolic resin and accounts for the high char yield.
文摘This article describes the synthesis of a series of aromatic amide-amines and their potential use as epoxy hardeners. These amines were synthesized by the reaction of L-phenylalanine （PA） with diamines of different structures i.e. 1,4- phenylene diamine （PD）, 1,5-diamino naphthalene （N）, 4,4＇-（9-fluorenyllidene）-dianiline （F）, 4,4＇-diaminodiphenyl sulphide （DS） and 3,4＇-oxydianiline （O） in a stoichiometric ratio （I ：1）. Structural characterization of synthesized amide-amines was done with the help of elemental analysis and spectroscopic techniques viz. FT-IR, 1H-NMR and 13C-NMR. An epoxy blend was prepared by mixing tris（glycidyloxy） phosphine oxide （TGPO） with conventional epoxy i.e. diglycidyl ether of bisphenol-A （DGEBA） in an equivalent ratio of 2：3 to incorporate phosphorous into the main chain. The curing kinetics of the epoxy blend with synthesized aromatic amide-amines was investigated by non-isothermal DSC technique using multiple heating rate method （5, 10, 15 and 20 K/min.）. The activation energies were determined by fitting the experimental data into Kissinger and Ozawa kinetic models. The activation energies obtained through Ozawa method were slightly higher than those of Kissinger method but were comparable. However, both the energies were found to be dependent on the structure of amines. The thermal stability and weight loss behavior of isothermally cured thermosets were also investigated using thermogravimetric analysis （TGA） in nitrogen atmosphere. All the samples showed improved thermal stability in terms of char yield than using only amines as hardeners.
文摘The curing behavior of diglycidyl ether of bisphenol-A(DGEBA) with aromatic diamide-diimide-diamines having aryl ether,sulfone and methylene linkages was studied by differential scanning calorimetry(DSC).Nine diamide-diimide-diamines of varying structure were synthesized by reacting 1 mole of dianhydride with 2 moles of L-cysteine(S) in a mixture of acetic acid and pyridine(3:2 V/V) followed by activation with thionyl chloride(SOCl_2) and then condensation with excess of diamines.Structural characterization...
基金Funded by the National Natural Science Foundation of China(No.51572205)the National Natural Science Foundation of Hubei Province,China(No.2014CFB854)the Equipment Pre-Research Joint Fund of EDD and MOE(No.6141A02033209)
文摘A novel epoxy-imide resin based on diglycidyl ether of bisphenol-A and N-（4-hydroxyphenyl）terahydrophthalic anhydrideimide（HTAM） was synthesized. The structural characterization of the epoxy-imide resin was conducted by FT-IR spectra. 4,4＇-diaminodiphneylmethane（DDM） was used as a curing agent for the epoxy-imide resin. The thermal properties of the cured resin were evaluated with dynamic mechanical analyses（DMA） and thermogravimetric analysis（TGA）. The results showed that the cured resin exhibited a high glass transition temperature（Tg） of 186 ℃ when the molar amount of HTAM was 0.04 mol in the resin. The yields of the cured resin at 800 ℃ raised from 16.45% to 19.41%. The flexural properties were also measured, the flexural strength raised from 79.4 to 95.7 MPa, and the flexural modulus exhibited from 2.6 to 3.0 GPa.
