Synthesis and characterization of novel poly(amide urea)s, materials with outstanding mechanical properties (original) (raw)
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Synthesis and characterization of a novel polyamidoamine–cyclodextrin crosslinked copolymer
Carbohydrate Research, 2011
A series of dodecylbenzene sulphonic acid (DBSA) doped poly(aniline-co-m-aminoacetophenone) copolymer composites of different compositions were synthesized in micellar solution of DBSA to obtain nanosphere morphology with enhanced processability. The plausible mechanism for the formation of poly(aniline-com-aminoacetophenone)-DBSA copolymer composite has been presented. These DBSA doped copolymer composites were characterized by UV-Visible, FTIR spectroscopy and XRD analysis techniques. UV-Vis absorption spectrum of the composites showed 325 and 637 nm which corresponds to the p-p* and n-p* transition. In FTIR spectroscopy a broad band around 2,924 cm-1 corresponds to C-H vibration of DBSA indicating good agreement with the characteristic bands of DBSA. The sharp band at 1,292 cm-1 is assigned to C-N stretching mode of vibration of N-Ph-N units. The X-ray diffraction of composites reveals that these composites are amorphous in nature. The number of diffraction peaks decreased with increase in the m-aminoacetophenone content. It indicates that these composites are amorphous in nature. Morphological studies (SEM) reveal that these composites have a spherical morphology with the average size of 100-200 nm. These composites exhibit electrical conductivity value of 0.744 9 10-3 S/cm and enhanced solubility than polyaniline. Moreover, at the presented work, the DBSA doped copolymer composites were obtained in high yields by keeping an oxidant to co-monomer ratio of 1:1.
Synthesis and Characterization of Novel Poly(Arylene Ether)s from 1,3‐bis(4‐Hydroxyphenyl) Benzene
Journal of Macromolecular Science, Part A, 2004
A series of dodecylbenzene sulphonic acid (DBSA) doped poly(aniline-co-m-aminoacetophenone) copolymer composites of different compositions were synthesized in micellar solution of DBSA to obtain nanosphere morphology with enhanced processability. The plausible mechanism for the formation of poly(aniline-com-aminoacetophenone)-DBSA copolymer composite has been presented. These DBSA doped copolymer composites were characterized by UV-Visible, FTIR spectroscopy and XRD analysis techniques. UV-Vis absorption spectrum of the composites showed 325 and 637 nm which corresponds to the p-p* and n-p* transition. In FTIR spectroscopy a broad band around 2,924 cm -1 corresponds to C-H vibration of DBSA indicating good agreement with the characteristic bands of DBSA. The sharp band at 1,292 cm -1 is assigned to C-N stretching mode of vibration of N-Ph-N units. The X-ray diffraction of composites reveals that these composites are amorphous in nature. The number of diffraction peaks decreased with increase in the m-aminoacetophenone content. It indicates that these composites are amorphous in nature. Morphological studies (SEM) reveal that these composites have a spherical morphology with the average size of 100-200 nm. These composites exhibit electrical conductivity value of 0.744 9 10 -3 S/cm and enhanced solubility than polyaniline. Moreover, at the presented work, the DBSA doped copolymer composites were obtained in high yields by keeping an oxidant to co-monomer ratio of 1:1.
Journal of Polymers and The Environment, 2006
Biodegradable polymers are one of the most 3 promising ways to replace non-degradable polymers. 4 But, to be a real alternative to classical synthetic 5 polymers and find applications, biopolymer (biode-6 gradable polymer) properties have to be enhanced. 7 Nano-biocomposites, which are obtained by incorpo-8 ration of nanofillers into a biomatrix, are an interesting 9 way to achieve these improvements. Modified and 10 unmodified montmorillonites have been introduced 11 into a biodegradable aromatic copolyester, poly(butyl-12 ene adipate-co-terephthalate) (PBAT). Structural 13 characterization, thermal and mechanical tests have 14 been carried out to understand better the relations 15 between the nanofillers structuring and the final nano-16 biocomposite properties. Main results show that clay 17 incorporation and the obtained intercalated structures 18 improve PBAT properties (enhanced thermal stability, 19 increased stiffness) and thus may increase the attrac-20 tiveness of this biopolymer. 21 Keywords Nano-biocomposites AE Biodegradable 22 polymer AE Poly(butylene adipate-co-terephthalate) AE 23 Layered silicates AE Montmorillonite 24 Introduction 25 Nowadays, most of the short-term application materi-26 als (e.g., packaging) are based on synthetic polymers. This situation is not entirely adequate because most of these long-lasting polymers produced from petrochemicals are not biodegradable and are a significant source of environmental pollution. Thus, reaching the conditions of conventional plastic replacements by degradable polymers is of major interest for different actors of the socio-economical life. However till now, biopolymers (biodegradable polymers) have not found extensive applications [1]. To be more attractive, some properties OF biopolymers have to be enhanced. Preparations of blends or conventional composites are among the possible routes to improve polymers properties [2]. A new area of composites called nanocomposites, in which the reinforcing material has nanometric scale, has emerged and seems to be very promising. For instance, at low level of nanofillers incorporation (less than 5 wt%) [3-4], the reinforcement efficiency of nanocomposites can match that of conventional composites with 40-50 wt% of loading with classical fillers. This improvement is due to the dispersion of nanoscale fillers into the matrix, which results in a high surface area with high interactions between nanofillers and the polymer matrix. The addition of nanofillers into a biodegradable polymer matrix leads to the creation of a novel class of materials, called nano-biocomposites which combine nano-materials with an environmental approach. Recent studies have been previously reported for the elaboration and characterization of these nano-materials, based on polylactide [5-7], poly(3-hydroxybutyrate)[8] and corresponding copolymers [9], plasticized starch [10-12], poly(butylene succinate) [13] or poly(ecaprolactone) [14-18]. Various nano-reinforcements are currently under investigation. The most intensive researches concern
International Journal of Scientific Research in Science and Technology, 2019
Nanocomposite of copolymer of N-Methyl pyrrole (NMPy) and N, N-Dimethyl aniline (NDMA) doped with HCl was synthesized by chemical oxidative polymerization. APS was used as oxidant. The sample was characterized by FTIR, TGA, XRD and four probe method. FTIR confirms the formation of copolymer and its structure. XRD analysis shows the amorphous nature of polymer nanocomposite. The electrical conductivity of sample was measured by using four probe method. Size and surface morphology were demonstrated by SEM.
Composites Part A-applied Science and Manufacturing, 2007
The synthesis of composites of n-dodecylbenzene sulfonate-doped polyaniline (PANI-DBSA) and poly(styrene-metal acrylate) ionomers is presented. The ionomers of lithium, sodium and potassium were prepared by emulsion polymerization at different styrene-tometal acrylate weight ratios. The composites made with the potassium ionomer exhibit the largest conductivity due to the higher content of acid groups that allows stronger interactions with the PANI chains compared to the Na and Li ionomers. IR spectroscopy suggests that hydrogen bonding interactions take place between PANI-DBSA chains and that amine salt groups form by chemical reactions between the amine groups of PANI and the acid groups of the ionomer. X-ray diffraction reveals that the ionomer affects the structural ordering of PANI-DBSA. All the PANI-DBSA-ionomer composites show higher thermal stability than the PANI-DBSA material. SEM shows a characteristic agglomerate morphology in all the composites. The composite showing the highest electrical conductivity was mixed with poly(n-butyl methacrylate) (PBMA) by extrusion and the films obtained have higher electrical conductivity than that of films of the same system without ionomer.
Chemical synthesis and characterization of aniline and o-anthranilic acid copolymer
European Polymer Journal, 2008
The chemical co-polymerization of aniline with o-anthranilic acid (AA) to form copolymer films has been made in aqueous hydrochloric acid medium. The copolymer films were monitored by using the quartz crystal microbalance (QCM) technique. The effect of AA and its concentrations on the film formation was investigated. The results were justified by measuring the UV-Vis absorption spectra for the in situ copolymer films grown onto glass slides immersed into the polymerization media and the in situ UV-Vis absorption spectra for the copolymer in the bulk during the co-polymerization. The conductivity for the copolymer films and powder pellets at different molar ratios of aniline/AA were measured. Also, the IR spectra, X-ray diffraction and the thermal gravimetric analysis for the copolymer powder formed in the bulk in the absence and presence of AA were measured and discussed. It is found that the presence of AA affects the yield, induction period, depletion time and growth rate of the film formation. It also affects the crystallinity, and conductivity as well as the solubility of the polymer. Finally, the dopant weight fraction (w) associated with the copolymer was determined. It is almost half the value determined for the polymer in absence of AA.
Journal of Polymer Science Part A-polymer Chemistry, 2005
Poly[isobutyl methacrylate-co-butanediol dimethacrylate-co-3-methacrylylpropylheptaisobutyl-T8-polyhedral oligomeric silsesquioxane] [P(iBMA-co-BDMA-co-MA-POSS)] nanocomposites with different crosslink densities and different polyhedral oligomeric silsesquioxane (MA-POSS) percentages (5, 10, 15, 20, and 30 wt %) were synthesized by radical-initiated terpolymerization. Linear [P(iBMA-co-MA-POSS)] copolymers were also prepared. The viscoelastic properties and morphologies were studied by dynamic mechanical thermal analysis, confocal microscopy, and transmission electron microscopy (TEM). The viscoelastic properties depended on the crosslink density. The dependence of viscoelastic properties on MA-POSS content at a low BDMA loading (1 wt %) was similar to that of linear P(iBMA-co-MA-POSS) copolymers. P(iBMA-co-1 wt % BDMA-co-10 wt % MA-POSS) exhibited the highest dynamic storage modulus (E′) values in the rubbery region of this series. The 30 wt % MA-POSS nanocomposites with 1 wt % BDMA exhibited the lowest E′. However, the E′ values in the rubbery region for P(iBMA-co-3 wt % BDMA-co-MA-POSS) nanocomposites with 15 and 30 wt % MA-POSS were higher than those of the parent P(iBMA-co-3 wt % BDMA) resin. MA-POSS raised the E′ values of all P(iBMA-co- 5 wt % BDMA-co-MA-POSS) nanocomposites in the rubbery region above those of P(iBMA-co-5 wt % BDMA), but MA-POSS loadings < 15 wt % had little influence on glass-transition temperatures (Tg's) and slightly reduced Tg values with 20 or 30 wt % POSS. Heating history had little influence on viscoelastic properties. No POSS aggregates were observed for the P(iBMA-co-1 wt % BDMA-co-MA-POSS) nanocomposites by TEM. POSS-rich particles with diameters of several micrometers were present in the nanocomposites with 3 or 5 wt % BDMA. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 355–372, 2005
Polyaniline–DBSA/polymer blends prepared via aqueous dispersions
Synthetic Metals, 2000
. Stable polyaniline-dodecyl benzene sulfonic acid PANI-DBSA aqueous dispersions were obtained by a unique method of aniline polymerization in the presence of DBSA, through an anilinium-DBSA complex appearing as solid needle-like particles, in an aqueous Ž . medium. The average size of the PANI primary particles, determined by small angle X-ray scattering SAXS , is 18.7 nm. These primary particles form aggregates, which further cluster into ; 50 mm agglomerates. PANI-DBSArpolymer blends were obtained by mixing an aqueous PANI-DBSA dispersion with an aqueous emulsion of the matrix polymer, followed by water evaporation. These blends exhibit Ž . electrical conductivity already at a very low PANI-DBSA content 0.5 wt.% . The conductivity level of the various blends depends on the PANI content, on the surfactant present in the polymer matrix emulsion, and it is practically independent of the polymer matrix Ž nature. Thus, a similar structuring mechanism prevails in these blends, irrespective of the polymer matrix contrary to solution and melt . blends . The PANI-DBSA particles strongly segregate within the polymer matrix, already in the combined aqueous dispersion, and upon drying, a very fine conductive network is formed. This strong segregation tendency leads to a conductive network formation already at low PANI-DBSA contents, thus generating the conductive blends. q
Synthesis and properties of novel poly(coumarin-amide)s
Journal of Applied Polymer Science, 2009
A novel monomer diacid, 6,6′-methylenebis(2-oxo-2H-chromene-3-carboxylic acid), was synthesized and used in a direct polycondensation reaction with various aromatic diamines in N-methyl-2-pyrrolidone solution containing dissolved LiCl and CaCl2, using triphenyl phosphite and pyridine as condensing agents to give a series of novel heteroaromatic polyamides containing photosensitive coumarin groups in the main chain. Polyamide properties were investigated by DSC, TGA, GPC, wide-angle X-ray scattering, viscosity, and solubility measurements. The copolymers were soluble in aprotic polar solvents, and their inherent viscosities varied between 0.49 and 0.78 dL g−1. The weight-average and number-average molecular weights, measured by gel permeation chromatography, were 27,500–43,900 g mol−1 and 46,500–66,300 g mol−1, respectively, and polydispersities in the range of 1.48–1.69. The aromatic polyamides showed glass-transition temperatures (Tg) ranging from 283 to 329°C and good thermal properties evidenced by no significant weight loss up to 380°C and 10% weight loss recorded above 425°C in air. All the polyamides exhibited an amorphous nature as evidenced by wide-angle X-ray diffraction and demonstrated a film forming capability. Water uptake values up to 3.35% were observed at 65% relative humidity. These polymers exhibited strong UV-vis absorption maxima at 357–369 nm in DMSO solution, and no discernible photoluminescence maxima were detected by exciting with 365 nm. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010