- Studies on mechanical, thermal and dynamic mechanical properties of functionalized nanoalumina reinforced sulphone ether linked tetraglycidyl epoxy nanocomposites
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The objective of the present work is to synthesize 1,4′-bis (4-amine-phenoxy) sulphone benzene epoxy resin (TGBAPSB) via 1,4′-bis (4-amine-phenoxy) sulphone benzene (BAPSB) and epichlorohydrin in order to obtain tetra functional epoxy with improved properties. The molecular structure of TGBAPSB epoxy resin was confirmed from FTIR and NMR spectral data and molecular weight was determined by GPC and epoxy equivalent weight (EEW) by titration method. The amino functionalized nanoalumina (F-nAl) was synthesized via the sol-gel method using 3-aminopropyltriethoxysilane and has been confirmed by FT-IR. TGBAPSB epoxy resin was further reinforced with varying weight percentages (1-5 wt%) of F-nAl and cured with diaminodiphenylmethane (DDM). The thermal and thermo-mechanical behaviour of TGBAPSB epoxy matrix and nanocomposites were analysed by TGA, DMA and DSC. The surface morphology of the epoxy nanocomposites was examined using XRD, TEM, SEM and AFM studies. Data obtained from mechanical, thermal and thermo-mechanical, dielectric and water absorption studies indicate a significant improvement in properties of the resultant epoxy nanocomposites, which appear to be ideal material for advanced high performance applications when compared to those of neat epoxy matrices. This journal is
- Duraibabu,Alagar,Kumar, S. Ananda
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- Synthesis and characterization of sulfone containing main chain oligobenzoxazine precursors
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The preparation of soluble and processable polybenzoxazine precursors capable of forming high performance networks is an important field of research with a broad spectrum of application. This study demonstrates an approach that utilizes aromatic sulfonediamine, bisphenol-A, and formaldehyde in Mannich-type polycondesation to prepare polybenzoxazine precursor. The structure of the oligomeric precursor (Mn = 2600) was confirmed by FTIR and 1H NMR spectral analysis. The precursor contained both sulfone and benzoxazine ring structures in the backbone. It was shown that small amount of ring-opened phenolic groups were also present. Thermally activated self-curing behavior of precursor in the absence of catalyst was studied by differential scanning calorimetry. Thermal properties of the cured polymers were also investigated by thermo gravimetric analysis.
- Altinkok, Cagatay,Kiskan, Baris,Yagci, Yusuf
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- Synthesis and characterization of novel bio-based benzoxazines from eugenol
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Polybenzoxazines are phenolic-like materials that possess dimensional and thermal stability, and they release no by-products during their polymerization. In this study, a new class of benzoxazine-containing monomers has been prepared from renewable resource (eugenol, a natural phenol obtained from clove oil), paraformaldehyde and various aromatic diamines. The structures of the monomers were supported by Fourier Transform Infrared (FT-IR), 1H-NMR and 13C-NMR spectral analysis, proving the existence of the benzoxazine ring containing eugenol moiety in its molecular structure. The monomers were polymerized/cured via ring-opening polymerization by heating as indicated by FT-IR and Differential Scanning Calorimetry (DSC). This is confirmed by the disappearance of the peaks due to oxazine ring (942 cm-1). The exothermic peak associated with curing was observed from 170°C to 250°C. The thermal and mechanical properties of the polybenzoxazines were investigated through thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The temperatures corresponding to 5% and 10% weight loss is from 240 to 295°C and from 290 to 340°C, respectively. The completely cured materials could achieve char yields up to 36.5% at 800°C in nitrogen atmosphere. DMA revealed that the glass transition temperatures of PBz-SUL and PBz-PHE were higher than that of PBz-DDS and PBz-OXY.
- Thirukumaran,Shakila,Muthusamy, Sarojadevi
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p. 7959 - 7966
(2014/02/14)
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- Functionalized Photoreactive Compounds
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The present invention concerns functionalized photoreactive compounds of formula (I), that are particularly useful in materials for the alignment of liquid crystals. Due to the adjunction of an electron withdrawing group to specific molecular systems bearing an unsaturation directly attached to two unsaturated ring systems, exceptionally high photosensitivities, excellent alignment properties as well as good mechanical robustness could be achieved in materials comprising said functionalized photoreactive compounds of the invention.
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- Thermoplastic resin composition and a method of molding the same
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This invention provides a thermoplastic resin composition comprising a thermoplastic resin and 0.1 to 100 parts by weight, per 100 parts by weight of the thermoplastic resin, of an imide compound prepared, e.g., by dehydration condensation of 1,2,3,4-butanetetracarboxylic acid or a monoanhydride or a dianhydride thereof with a primary amine, and a method of molding the resin composition.
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- Process for the preparation of 4,4'-bis(4-aminophenoxy)-diphenyl sulfone
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High purity 4,4'-bis(4-aminophenoxy)diphenyl sulfone is prepared from p-aminophenol, alkali metal hydroxide and 4,4'-dihalodiphenyl sulfone by using a molar ratio of alkali metal hydroxide: 4-aminophenol in the range of 1.0-1.1:1.0 and a molar ratio of 4-aminophenol: 4,4'-dihalodiphenyl sulfone in the range of 2.005-2.05:1.0 and by using a dialkylamide or N-alkyl lactam as a solvent. Pristine products (no-recrystallization) of 99.0% purity having melting points above 195° C. are obtained.
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- Synthesis of phthalonitrile resins containing ether and imide linkages
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Imide-containing phthalonitrile monomers are prepared from a phthalonitrile and an aromatic dianhydride. The monomer and a method for preparing the monomer is disclosed. These monomers are synthesized into heat resistant polymers and copolymers with aromatic ring structure incorporating imide and ether linkages. The synthesis of the high temperature thermosetting polymers and copolymers is also disclosed.
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