19022-06-1Relevant articles and documents
Chiral bio-nanocomposites based on thermally stable poly(amide-imide) having phenylalanine linkages and reactive organoclay containing tyrosine amino acid
Mallakpour, Shadpour,Dinari, Mohammad
, p. 1021 - 1029 (2013/07/27)
Montmorillonite clay modified with the bio-active trifunctional l-tyrosine amino acid salt was used as a reactive organoclay (OC) for the preparation of poly(amide-imide) (PAI)/OC hybrid films. One of the functional groups of the l-tyrosine as the swelling agent formed an ionic bond with the negatively charged silicates, whereas the remaining functional groups were available for further reaction with polymer matrix. The soluble PAI with amine end groups including phenylalanine amino acid was synthesised under green condition using molten tetra-butylammonium bromide by direct polymerization reaction of chiral diacid and 2-(3,5-diaminophenyl)benzimidazole. PAI/OC bio-nanocomposites films containing different contents of OC were prepared via solution intercalation method through blending of OC with the PAI solution. X-ray diffraction and transmission electron microscopy revealed that the dispersion of silicate layers in the PAI created an exfoliated structure as a result of using the trifunctional groups of the swelling agent. The structure and thermal behavior of the synthesised materials were characterized by a range of methods, including X-ray diffraction, Fourier transform infrared spectroscopy, 1H-NMR, electron microscopy, elemental and thermogravimetric analysis techniques. Thermogravimetric analysis results indicated that the addition of OC into the PAI matrix was increased in the thermal decomposition temperatures of the resulted bio-nanocomposites.
Investigating the nanostructure and thermal properties of chiral poly(amide-imide)/Al2O3 compatibilized with 3-aminopropyltriethoxysilane
Mallakpour, Shadpour,Dinari, Mohammad
, p. 3865 - 3872 (2013/09/02)
Novel chiral poly(amide-imide) (PAI)/Al2O3 nanocomposites were prepared via incorporating surface modified Al 2O3 nanoparticles into polymer matrices for the first time. In the process of preparing the nanocomposites, severe aggregation of Al2O3 nanoparticles could be reduced by surface modification and γ-aminopropyltriethoxysilane. The optically active PAI chains were formed from the polycondensation reaction of N,N′- (pyromellitoyl)-bis-phenylalanine diacid with 2-(3,5-diaminophenyl)- benzimidazole in green condition. The obtained polymer and inorganic metal oxide nanoparticles were used to prepare chiral PAI/Al2O3 nanocomposites through ultrasonic irradiation. The resulting nanoparticle filled composites were also characterized by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and thermogravimetric analysis (TGA) techniques. TGA thermographs confirmed that the heat stability of the prepared nanoparticle-reinforced composites was improved. Mechanical properties showed that the film containing 10 wt% of modified Al2O3 had a tensile strength of the order of 83.6 MPa, relative to the 64.3 MPa of the pure PAI.
Synthesis, characterization and fuel cell application of polyimides
Lee, Minju,Khan, Sher B.,Seo, Kwangwon,Lee, Jin-Woo,Akhtar, Kalsoom,Han, Haksoo,Asiri, Abdullah M.
, p. 655 - 659 (2013/03/13)
Proton conducting polyimides containing pendant benzimidazole groups have been synthesized by different ratios of 5-(1H-benzimidazol-2-yl)-benzene-1-3- diamine (DABI) and oxydianiline (ODA) in the presence of oxydianiline (ODPA). All the polymers were str
