The Experts below are selected from a list of 732900 Experts worldwide ranked by ideXlab platform
Chin-ping Yang - One of the best experts on this subject based on the ideXlab platform.
-
novel organosoluble poly amide imide imide s synthesized from new tetraimide dicarboxylic acid by condensation with 4 4 oxydiphthalic anhydride 1 4 bis 4 amino 2 trifluoromethylphenoxy benzene trimellitic anhydride and various aromatic diamines
Journal of Applied Polymer Science, 2006Co-Authors: Chin-ping Yang, Yaping Chen, Eamor M WooAbstract:A new monomer of tetraimide-dicarboxylic acid (IV) was synthesized by starting from ring-opening addition of 4,4′-oxydiphthalic anhydride, trimellitic anhydride, and 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene at a 1:2:2 molar ratio in N-methyl-2-pyrrolidone (NMP). From this new monomer, a series of novel organosoluble poly(amide-imide-imide)s with inherent viscosities of 0.7–0.96 dL/g were prepared by triphenyl phosphite activated polycondensation from the tetraimide-diacid with various aromatic diamines. All synthesized polymers were readily soluble in a variety of organic solvents such as NMP and N,N-dimethylacetamide, and most of them were soluble even in less polar m-cresol and pyridine. These polymers afforded tough, transparent, and flexible films with tensile strengths ranging from 99 to 125 MPa, elongations at break from 12 to 19%, and initial moduli from 1.6 to 2.4 GPa. The thermal properties and stability were also good with glass-transition temperatures of 236–276°C and thermogravimetric analysis 10 wt % loss temperatures of 504–559°C in nitrogen and 499–544°C in air. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2854–2864, 2006
-
novel organosoluble and colorless poly ether imide s based on 3 3 bis 4 3 4 dicarboxyphenoxy phenyl phthalide dianhydride and aromatic bis ether amine s bearing pendent trifluoromethyl groups
Journal of Polymer Science Part A, 2006Co-Authors: Chin-ping YangAbstract:A novel series of colorless and highly organosoluble poly(ether imide)s were prepared from 3,3-bis[4-(3,4-dicarboxyphenoxy)phenyl]phthalide dianhydride with various fluorinated aromatic bis(ether amine)s via a conventional two-stage process that included ring-opening polyaddition to form the poly(amic acid)s followed by cyclodehydration to produce the polymer films. The poly(ether imide)s showed excellent solubility, with most of them dissoluble at a concentration of 10 wt % in amide polar solvents, in ether-type solvents, and even in chlorinated solvents. Their films had a cutoff wavelength between 358 and 373 nm, and the yellowness index ranged from 3.1 to 9.5. The glass-transition temperatures of the poly(ether imide) series were recorded between 237 and 297 °C, the decomposition temperatures at 10% weight loss were all above 494 °C, and the residue was more than 54% at 800 C in nitrogen. These films showed high tensile strength and also were characterized by higher solubility, lighter color, and lower dielectric constants and moisture absorption than an analogous nonfluorinated polyimide series.
-
new soluble poly amide imide imide s based on tetraimide dicarboxylic acid condensed from 4 4 oxydiphthalic anhydride 2 2 bis 4 4 aminophenoxy phenyl sulfone and p aminobenzoic acid and various aromatic diamines
European Polymer Journal, 2002Co-Authors: Chin-ping Yang, Ruei-shin Chen, Chishu WeiAbstract:Abstract A new-type tetraimide-dicarboxylic acid ( I ) was synthesized starting from the ring-opening addition of p-aminobenzoic acid, 4,4′-oxydiphthalic anhydride, and 2,2-bis[4-(4-aminophenoxy)phenyl]sulfone (BAPS) at a 2:2:1 molar ratio in N-methyl-2-pyrrolidone (NMP), followed by cyclodehydration to the diacid I . A series of poly(amide–imide–imide)s ( III a–i ) with inherent viscosities of 0.71–0.99 dl/g was prepared by triphenyl phosphite-activated polycondensation from the tetraimide-diacid I with various aromatic diamines ( II a–i ) in a medium consisting of NMP, pyridine, and calcium chloride. All of the polymers were readily soluble in a variety of organic solvents such as NMP, N,N-dimethyl acetamide, dimethyl sulfoxide, and even in less polar m-cresol. Compared with those of the corresponding poly(amide–imide)s IV a–i , the solubilities of poly(amide–imide–imide)s III a–i were greatly improved. Most of the polymers III afforded tough, transparent, and flexible films, which had a tensile strength ranging from 94 to 100 MPa, elongation at break from 7 to 9%, and initial tensile modulus from 2.0 to 2.3 GPa. The glass transition temperature of polymers was recorded at 265–291 °C. They had 10% weight loss at a temperature above 550 °C and left more than 50% residue even at 800 °C in nitrogen.
-
synthesis and properties of organosoluble poly amide imide imide s based on tetraimide dicarboxylic acid condensed from 4 4 hexafluoroisopropylidene diphthalic anhydride 4 4 oxydianiline and trimellitic anhydride and various aromatic diamines
Journal of Polymer Science Part A, 2002Co-Authors: Chin-ping Yang, Ruei-shin Chen, Mingjui WangAbstract:A novel tetraimide dicarboxylic acid was synthesized with the ring-opening addition of 4,4′-(hexafluoroisopropylidene)diphthalic anhydride, 4,4′-oxydianiline, and trimellitic anhydride in a 1/2/2 molar ratio in N-methyl-2-pyrrolidone followed by azeotropic condensation to tetraimide dicarboxylic acid. A series of poly(amide imide imide)s (PAIIs) with inherent viscosities of 0.8–1.1 dL/g were prepared from tetraimide dicarboxylic acid with various aromatic diamines by direct polycondensation. Most of the PAIIs were readily soluble in a variety of amide polar solvents and even in less polar m-cresol and pyridine. Solvent-cast films had tensile strengths ranging from 99 to 106 MPa, elongations at break ranging from 8 to 13%, and initial moduli ranging from 2.0 to 2.3 GPa. The glass-transition temperatures of these PAIIs were recorded at 244–276 °C. They had 10% weight losses at temperatures above 520 °C in air or nitrogen atmospheres. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1092–1102, 2002
-
synthesis and properties of poly amide imide s containing a n methylcarbazole group
Colloid and Polymer Science, 2000Co-Authors: Chin-ping Yang, Ruei-shin Chen, C.-c. ChangAbstract:A new dicarboxylic acid monomer containing the N-methylcarbazole and imide structures, 3,6-bis(trimellitimido)-N-methylcarbazole (I), was prepared from the condensation of 3,6-diamino-N-methylcarbazole (c) and trimellitic anhydride. The diamine c was synthesized in three steps starting from the methylation of carbazole, followed by nitration and catalytic hydrazine reduction. A series of N-methylcarbazole-containing poly(amide–imide)s were synthesized by direct polycondensation from the diimide–diacid I with various aromatic diamines. These poly(amide–imide)s had inherent viscosities of 0.66–1.47 dl/g and were readily soluble in a variety of organic solvents, including N-methyl-2-pyrrolidone and N,N-dimethylacetamide (DMAc). Transparent, flexible, and tough films of these polymers could be cast from DMAc solutions, and these films exhibited excellent mechanical strength. The glass-transition temperatures of these poly(amide–imide)s were in the range 317–362 °C. All the poly (amide–imide) did not degrade noticeably below 480 °C in nitrogen, and the 10% weight loss temperatures and char yields at 800 °C were above 520 °C and 60% in nitrogen, respectively, indicating high thermal stability.
Philippe Michaud - One of the best experts on this subject based on the ideXlab platform.
-
low molecular weight poly imide amide s obtained by copolycondensation of 4 4 methylenedi phenyl isocyanate trimellitic anhydride and benzoic acid in n methyl 2 pyrrolidone 3 absolute number average molecular weights and glass transition temperatures
Macromolecular Chemistry and Physics, 1997Co-Authors: Nathalie Sinteszydowicz, Quang Tho Pham, Jacque Dubois, Philippe MichaudAbstract:In depth study of low molecular weight poly(imide-amide)s (PIA) obtained by copolycondensation of 4,4'-methylenedi(phenyl isocyanate), trimellitic anhydride and benzoic acid by 1 H and 13 C NMR spectroscopy and size-exclusion chromatography allows the determination of their absolute number-average molecular weights M n,abs . Viscosimetric measurements reveal that, dissolved in N-methyl-2-pyrrolidone, these low molecular weight PIAs should be semi-rigid because of the presence of very short crystalline chains. By using the semi-empirical Fox-Flory relation, the extrapolated glass transition temperature equals 300 °C for high molecular weight.
-
low molecular weight poly imide amide s obtained by copolycondensation of 4 4 methylenedi phenyl isocyanate trimellitic anhydride and benzoic acid in n methyl 2 pyrrolidone 2 structural defects observed by 1h and 13c nmr
Macromolecular Chemistry and Physics, 1996Co-Authors: Nathalie Sinteszydowicz, Quang Tho Pham, Philippe MichaudAbstract:The in depth examination (by 1 H and 13 C NMR, DSC, SEC and TGA) of the low-molecular-weight poly(imide-amide)s synthesized with the mixture [4,4'-methylenedi(phenyl isocyanate) (M) + trimellitic acid anhydride (T) + benzoic acid (B)] in N-methyl-2-pyrrolidone (NMP) at temperatures lower than 180°C allowed the identification and quantitative determinations of all the unexpected and relatively stable structures. While amide functions are readily synthesized, the formation of imide from anhydride and isocyanate functions passes through 4-amido-1,2-benzenedicarboxylic acid (T i ), 1,4-di-amido-2-benzenecarboxylic acid (T) and disubstituted urea (u). At 180 °C T i completely disappears but traces of T and u remain ; thus, the formation of imide can never reach its theoretical quantity. Traces of moisture in NMP may play the role of catalyst in the formation of imide, and reaction mechanisms are proposed.
-
low molecular weight poly imide amide s obtained by copolycondensation of 4 4 methylenedi phenyl isocyanate trimellitic acid anhydride and benzoic acid in n methyl 2 pyrrolidone 1 the microstructure studied by 1h and 13c nmr
Macromolecular Chemistry and Physics, 1993Co-Authors: Nathalie Sinteszydowicz, Quang Tho Pham, Philippe MichaudAbstract:Low-molecular-weight poly(imide-amide)s (PIA) obtained by polycondensation at 180°C of 4,4'-methylenedi(phenyl isocyanate), trimellitic acid anhydride and benzoic acid were studied by 1 H and 13 C NMR. Complementary 1 H and 13 C information was used to determine the distribution of II, IA, AA sequences and to show that the repartition of imide (I) and amide (A) groups along the chains is random. According to the composition of the monomer mixture, a slight deficiency of I is reproducibly observed. Non-reacted benzoic acid is found, and unexpected traces of urea and amic acid groups are present in the PIA chains
Nathalie Sinteszydowicz - One of the best experts on this subject based on the ideXlab platform.
-
low molecular weight poly imide amide s obtained by copolycondensation of 4 4 methylenedi phenyl isocyanate trimellitic anhydride and benzoic acid in n methyl 2 pyrrolidone 3 absolute number average molecular weights and glass transition temperatures
Macromolecular Chemistry and Physics, 1997Co-Authors: Nathalie Sinteszydowicz, Quang Tho Pham, Jacque Dubois, Philippe MichaudAbstract:In depth study of low molecular weight poly(imide-amide)s (PIA) obtained by copolycondensation of 4,4'-methylenedi(phenyl isocyanate), trimellitic anhydride and benzoic acid by 1 H and 13 C NMR spectroscopy and size-exclusion chromatography allows the determination of their absolute number-average molecular weights M n,abs . Viscosimetric measurements reveal that, dissolved in N-methyl-2-pyrrolidone, these low molecular weight PIAs should be semi-rigid because of the presence of very short crystalline chains. By using the semi-empirical Fox-Flory relation, the extrapolated glass transition temperature equals 300 °C for high molecular weight.
-
low molecular weight poly imide amide s obtained by copolycondensation of 4 4 methylenedi phenyl isocyanate trimellitic anhydride and benzoic acid in n methyl 2 pyrrolidone 2 structural defects observed by 1h and 13c nmr
Macromolecular Chemistry and Physics, 1996Co-Authors: Nathalie Sinteszydowicz, Quang Tho Pham, Philippe MichaudAbstract:The in depth examination (by 1 H and 13 C NMR, DSC, SEC and TGA) of the low-molecular-weight poly(imide-amide)s synthesized with the mixture [4,4'-methylenedi(phenyl isocyanate) (M) + trimellitic acid anhydride (T) + benzoic acid (B)] in N-methyl-2-pyrrolidone (NMP) at temperatures lower than 180°C allowed the identification and quantitative determinations of all the unexpected and relatively stable structures. While amide functions are readily synthesized, the formation of imide from anhydride and isocyanate functions passes through 4-amido-1,2-benzenedicarboxylic acid (T i ), 1,4-di-amido-2-benzenecarboxylic acid (T) and disubstituted urea (u). At 180 °C T i completely disappears but traces of T and u remain ; thus, the formation of imide can never reach its theoretical quantity. Traces of moisture in NMP may play the role of catalyst in the formation of imide, and reaction mechanisms are proposed.
-
low molecular weight poly imide amide s obtained by copolycondensation of 4 4 methylenedi phenyl isocyanate trimellitic acid anhydride and benzoic acid in n methyl 2 pyrrolidone 1 the microstructure studied by 1h and 13c nmr
Macromolecular Chemistry and Physics, 1993Co-Authors: Nathalie Sinteszydowicz, Quang Tho Pham, Philippe MichaudAbstract:Low-molecular-weight poly(imide-amide)s (PIA) obtained by polycondensation at 180°C of 4,4'-methylenedi(phenyl isocyanate), trimellitic acid anhydride and benzoic acid were studied by 1 H and 13 C NMR. Complementary 1 H and 13 C information was used to determine the distribution of II, IA, AA sequences and to show that the repartition of imide (I) and amide (A) groups along the chains is random. According to the composition of the monomer mixture, a slight deficiency of I is reproducibly observed. Non-reacted benzoic acid is found, and unexpected traces of urea and amic acid groups are present in the PIA chains
Sheng-huei Hsiao - One of the best experts on this subject based on the ideXlab platform.
-
thermally stable and organosoluble poly amide imide s based on the imide ring preformed dicarboxylic acids derived from 3 4 oxydianiline with trimellitic anhydride and 6fda
Journal of Macromolecular Science Part A, 2017Co-Authors: Yungchung Chen, Sheng-huei HsiaoAbstract:ABSTRACTA diimide-dicarboxylic acid (DIDA) (I) was prepared from the condensation reaction of trimellitic anhydride (TMA) and 3,4′-oxydianiline (3,4′-ODA) in a 2:1 molar ratio, and another new tetraimide-dicarboxylic acid (TIDA) (II) was synthesized by condensation from 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), TMA, and 3,4′-ODA in a 1:2:2 molar ratio. Two series of aromatic poly(amide-imide)s (PAI) IVa-k and Va-k were synthesized by Yamazaki phosphorylation polyamidation reactions of DIDA I and TIDA II, respectively, with various aromatic diamines. Due to highly random segmental sequence for both series in the polymer chain and the incorporation of 6FDA moieties for the V series, all the polymers were readily soluble in many organic solvents and could be casted into transparent, flexible, and tough films with good mechanical properties. Glass-transition temperature (Tgs) of the IV series and V series were recorded in the range of 242–274°C and 264–295°C. In addition, almost all the poly...
-
synthesis and characterization of electrochromic poly amide imide s based on the diimide diacid from 4 4 diamino 4 methoxytriphenylamine and trimellitic anhydride
European Polymer Journal, 2010Co-Authors: Sheng-huei Hsiao, Gueysheng Liou, Yichun Kung, Yiju LeeAbstract:Abstract A dicarboxylic acid bearing two preformed imide rings, namely 4,4′-bis(trimellitimido)-4″-methoxytriphenylamine ( 3 ), was prepared by the condensation of 4,4′-diamino-4″-methoxytriphenylamine ( 2 ) and two molar equivalents of trimellitic anhydride (TMA). A new family of aromatic poly(amide–imide)s (PAIs) containing the electroactive triphenylamine (TPA) unit were prepared by the triphenyl phosphite activated polycondensation of the diimide-diacid 3 with various aromatic diamines. All the polymers were readily soluble in many organic solvents and could be solution-cast into tough and flexible polymer films. They displayed high glass-transition temperatures (269–313 °C) and good thermal stability, with 10% weight-loss temperatures in excess of 521 °C in nitrogen and char yields at 800 °C in nitrogen higher than 68%. Cyclic voltammograms of the PAI films cast onto an indium–tin oxide (ITO)-coated glass substrate exhibited one reversible oxidation redox couple at 0.91–0.93 V vs. Ag/AgCl in acetonitrile solution. The polymer films revealed a good electrochemical and electrochromic stability, with a color change from colorless neutral form to blue oxidized form at applied potentials ranging from 0.0 to 1.2 V. The PAIs containing the TPA unit in both imide and amide segments showed multicolor electrochromism: pale yellow in the neutral state, green in the semi-oxidized state, and deep blue in the fully oxidized state.
-
synthesis and properties of new organosoluble and alternating aromatic poly ester amide imide s with pendant phosphorus groups
Journal of Polymer Science Part A, 2001Co-Authors: Gueysheng Liou, Sheng-huei HsiaoAbstract:New phosphorus-containing aromatic diesteramines, 1,4-bis(4-aminobenzoyloxy)-2-(6-oxido-6H-dibenz〈c,e〉〈1,2〉oxaphosphorin-6-yl)naphthalene (p-3) and 1,4-bis(3-aminobenzoyloxy)-2-(6-oxido-6H-dibenz〈c,e〉〈1,2〉oxaphosphorin-6-yl)naphthalene (m-3), were synthesized by the reaction of 2-(6-oxido-6H-dibenz〈c,e〉〈1,2〉oxaphosphorin-6-yl)-1,4-naphthalenediol with 4-nitrobenzoyl chloride and 3-nitrobenzoyl chloride, respectively, followed by catalytic reduction. Two series of phosphorus-containing aromatic poly(ester-amide-imide)s with inherent viscosities of 0.94–2.00 and 0.41–0.56 dL/g were prepared via low-temperature solution polycondensation from p-3 and m-3, respectively, with three imide ring-preformed diacid chlorides. All the poly(ester-amide-imide)s were amorphous and readily soluble in many organic solvents such as N,N-dimethylacetamide (DMAc) and N-methyl-2-pyrrolidone (NMP). Transparent, tough, and flexible films of these polymers were cast from DMAc or NMP solutions. Their casting films possessed a tensile strength range of 118–181 MPa, an elongation to break of 5–11%, and an initial modulus range of 2.41–4.46 GPa. They had useful levels of thermal stability associated with relatively high glass-transition temperatures (264–286 °C) and 10% weight-loss temperatures in excess of 450 °C in nitrogen or air. The limiting oxygen indices of these polymers were 41–46. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1786–1799, 2001
-
synthesis and characterization of new aromatic poly amide imide s derived from 1 4 bis 4 aminophenoxy 2 t butylbenzene and various bis trimellitimide s
Materials Chemistry and Physics, 2000Co-Authors: Chin-ping Yang, Sheng-huei Hsiao, Hueiwen YangAbstract:Abstract A series of novel t-butyl group-containing poly(amide–imide)s III a – m were synthesized by the direct polycondensations of 1,4-bis(4-aminophenoxy)-2-t-butylbenzene (BAP-tBB) with various aromatic bis(trimellitimide)s II a – m in N-methyl-2-pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. Poly(amide–imide)s III having inherent viscosities between 0.67 and 1.77 dl g−1 were obtained in quantitative yields. Most of the resulting polymers were readily soluble in polar solvents such as NMP and N,N-dimethylacetamide. All of the soluble poly(amide–imide)s afforded transparent, flexible, and tough films. The glass transition temperatures of these polymers were in the range of 243–300°C, and the 10% weight loss temperatures were above 490°C in nitrogen. The properties of poly(amide–imide)s III were compared with those of the corresponding poly(amide–imide)s III′ prepared from the bis(trimellitimide) of BAP-tBB and various aromatic diamines.
-
synthesis and evaluation of novel polyimides derived from spirobichroman diether anhydride
Journal of Polymer Science Part A, 1997Co-Authors: Sheng-huei Hsiao, Chingyen YangAbstract:A spirobichroman structure-containing diether anhydride (SBCDA), 6,6'-bis (3,4-dicarboxyphenoxy ) -4,4,4',4,7,7'-hexamethyl-2,2'-spirobichroman dianhydride, was prepared by the nucleophilic nitrodisplacement of 4-nitrophthalonitrile with the phenolate ion of 6,6'-dihydroxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichroman, followed by alkaline hydrolysis of the intermediate tetranitrile and dehydration of the resulting tetraacid. A series of high molecular weight poly(ether imide)s with inherent viscosities between 0.45 and 1.28 dL/g were synthesized from SBCDA and various aromatic diamines via a conventional two-stage procedure that included ring-opening polyaddition in N,N-dimethylacetamide (DMAc) to give poly(amic acid)s, followed by thermal cyclization to poly(ether imide)s. The intermediate poly(amic acid)s had inherent viscosities of 0.70-1.50 dL/g. Except for the poly(ether imide) obtained from p-phenylenediamine, the other poly(ether imide)s were soluble in various organic solvents and could be solution-cast into transparent, flexible, and tough films. These poly(ether imide)s had glass transition temperatures in the range 175-262°C and showed no significant decomposition below 420°C, with 10% weight loss being recorded above 446°C in nitrogen or air.
Shadpour Mallakpour - One of the best experts on this subject based on the ideXlab platform.
-
the effect of the coupling agents kh550 and kh570 on the nanostructure and interfacial interaction of zinc oxide chiral poly amide imide nanocomposites containing l leucine amino acid moieties
Journal of Materials Science, 2014Co-Authors: Shadpour Mallakpour, Maryam MadaniAbstract:In this article, a series of optically active poly(amide–imide)/zinc oxide nanocomposites (PAI/ZnO NCs) with different ZnO contents were prepared by ultrasonic technique. For better dispersion of nanoparticles (NPs) in the PAI matrix, their surface was modified with two different silane coupling agents. Then, the effects of two linkers on dispersity of NPs, thermal stability and UV–Visible spectra of resulting NCs were investigated. The morphological structures, thermal, and UV properties of the prepared NCs with two different coupling agents were studied by X-ray diffraction, transmission electron micrograph, field emission scanning electron microscopy, thermogravimetric analysis, and UV–Visible analysis. These data demonstrated that the surface-modified ZnO NPs were homogeneously dispersed in the PAI matrix. However, in the case of KH570 the better dispersity is more pronounced.
-
the effect of carboxylated multi walled carbon nanotubes on reinforcement efficiency of thiazole bearing poly amide imide composites
Designed Monomers and Polymers, 2014Co-Authors: Shadpour Mallakpour, Amin ZadehnazariAbstract:Multi-walled carbon nanotube (MWCNT)/amino acid-based poly(amide-imide) (PAI) composites containing pendant thiazole moiety were successfully prepared through ultrasonication-assisted solution blending. In order to improve the compatibility between the PAI and MWCNTs, carboxylated MWCNTs were used in this study. The mechanical and thermal properties and cross-sectional morphology of the composites were investigated. The incorporation of MWCNTs–(COOH)n improved the mechanical properties of the composites compared with that of neat PAI. An improvement in thermal properties of the MWCNT/PAI composites was also observed. This synergetic enrichment in mechanical and thermal properties of the composites is due to the increased interfacial interactions resulted from the improved dispersion state and entanglement of polymer chains, as revealed by electron microscopy observation.
-
design and characterization of chiral and thermally stable nanostructure poly amide imide s containing different trimellitylimido amino acid based diacids and 4 4 methylenebis 3 chloro 2 6 diethylaniline units
Polymer-plastics Technology and Engineering, 2013Co-Authors: Shadpour Mallakpour, Kazem BanihassanAbstract:In this study new chiral nanostructure poly(amide-imide)s (PAI)s were synthesized via direct polycondensation of different trimellitylimido-amino acid-based diacids and 4,4′-methylenebis(3-chloro-2,6-diethylaniline), using tetra-n-butylammonium bromide and triphenyl phosphite as a green media. The formation of these nanostructure PAIs was confirmed by 1H-NMR, Fourier transform infrared spectroscopy, specific rotation, elemental analysis, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and thermo gravimetric analysis techniques. The FE-SEM micrographs and XRD patterns showed that, the obtained PAIs are nanostructured with different shapes and noncrystalline polymers.
-
chiral poly amide imide carbon nanotube bionanocomposites containing hydroxyl pendant groups and l phenylalanine amino acid synthesis preparation of thin films and thermomechanical behavior
Soft Materials, 2013Co-Authors: Shadpour Mallakpour, Amin ZadehnazariAbstract:Nanocomposites (NC)s of carboxyl functionalized multi-walled carbon nanotubes (f-MWCNTs) that reinforced poly(amide-imide) have been created via a simple solution casting technique. X-ray diffraction, FT-IR spectroscopy, transmission electron microscopy, and field emission scanning electron microscopy were carried out to characterize the composites. The thermal stability of the NCs was improved due to the enhanced interfacial interaction and good dispersion between the polymer matrix and modified CNTs. The reinforcing effect of the content of MWCNTs on the mechanical properties of the NCs has been evaluated, and it is found that the tensile properties were increased with the increasing content of f-MWCNTs.
-
optically active poly amide imide tio2 bionanocomposites containing l isoleucine amino acid moieties synthesis nanostructure and properties
Polymer-plastics Technology and Engineering, 2013Co-Authors: Shadpour Mallakpour, Abdolvahid BaratiAbstract:In the present investigation, novel poly(amide-imide) (PAI)/titanium dioxide (TiO2) bionanocomposites were prepared via ultrasonic irradiation process using TiO2 nanoparticles modified by γ-aminopropyltriethoxyl silane. Optically active PAI containing L-isoleucine natural amino acid was synthesized in tetrabutyl ammonium bromide/triphenyl phosphite mixture and used as a polymer matrix. The nanostructure characterization results confirmed that the surface of TiO2 nanoparticle has sufficient compatibility with PAI through the link of the coupling agent between TiO2 and polymer. Through TEM photographs, it can be found that the surface modified TiO2 nanoparticles with nanodiametric size of less than 40 nm, uniformly dispersed in the PAI matrix.