TY  - JOUR
AU  - Tomić, Milos
AU  - Dunjić, Branko
AU  - Nikolić, Marija S.
AU  - Trifković, Kata
AU  - Stanković, Nadezda
AU  - Pavlović, Vladimir
AU  - Bajat, Jelena
AU  - Djonlagić, Jasna
PY  - 2019
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/5068
AB  - In the present study the commercial multifunctional fatty acid polyamidoamine (PAA) was for the first time simultaneously applied as a curing agent and clay modifier for epoxy/clay nanocomposites (NC) based on diglycidyl ether of bisphenol A. The montmorillonite (Cloisite (R) Na+) was modified with different quantities of partially and fully protonated polyamidoamine. The NCs with 0.5 wt% novel organoclay were prepared by solution intercalation method. The major aims of this paper are investigations of the effects of the composition of PAA modified clays on structure, mechanical, barrier properties and corrosion stability on steel substrates of NCs were studied. The thermogravimetric, flame photometry and X-ray diffraction analyses confirmed the efficient modification of clay surface with polyamidoamine, predominantly located within layers. The NCs exhibited an intercalated/exfoliated morphology and the presence of free amino groups and increased content of modifier facilitated dispersion of clay particles within the polymer matrix, as shown by electron microscopy techniques (SEM, TEM). Under an optimized loading of PAA (molar quantity of total amino groups per clay cation exchange capacity of 1.75), the layers in stacks were separated by 5.0 nm and high number of individual layers was present in NC. Clay modified by PAA with free amino groups showed increased storage modulus in the rubbery state, glass transition temperature of NCs, while dumping factor was decreased. The tensile test confirmed that introduction of flexible modifier on the epoxy/clay interface lead to increase in the ultimate tensile strenght and elongation at break by 31% and toughness up to 83%. The electrochemical impedance spectroscopy and permeability tests proved the pronounced barrier effect of clay particles against corrosive species and water vapor when high dispersion degree of clay in NC was achieved.
PB  - Elsevier Science Sa, Lausanne
T2  - Progress in Organic Coatings
T1  - Polyamidoamine as a clay modifier and curing agent in preparation of epoxy nanocomposites
EP  - 321
SP  - 311
VL  - 131
DO  - 10.1016/j.porgcoat.2019.02.037
ER  - 

@article{
author = "Tomić, Milos and Dunjić, Branko and Nikolić, Marija S. and Trifković, Kata and Stanković, Nadezda and Pavlović, Vladimir and Bajat, Jelena and Djonlagić, Jasna",
year = "2019",
abstract = "In the present study the commercial multifunctional fatty acid polyamidoamine (PAA) was for the first time simultaneously applied as a curing agent and clay modifier for epoxy/clay nanocomposites (NC) based on diglycidyl ether of bisphenol A. The montmorillonite (Cloisite (R) Na+) was modified with different quantities of partially and fully protonated polyamidoamine. The NCs with 0.5 wt% novel organoclay were prepared by solution intercalation method. The major aims of this paper are investigations of the effects of the composition of PAA modified clays on structure, mechanical, barrier properties and corrosion stability on steel substrates of NCs were studied. The thermogravimetric, flame photometry and X-ray diffraction analyses confirmed the efficient modification of clay surface with polyamidoamine, predominantly located within layers. The NCs exhibited an intercalated/exfoliated morphology and the presence of free amino groups and increased content of modifier facilitated dispersion of clay particles within the polymer matrix, as shown by electron microscopy techniques (SEM, TEM). Under an optimized loading of PAA (molar quantity of total amino groups per clay cation exchange capacity of 1.75), the layers in stacks were separated by 5.0 nm and high number of individual layers was present in NC. Clay modified by PAA with free amino groups showed increased storage modulus in the rubbery state, glass transition temperature of NCs, while dumping factor was decreased. The tensile test confirmed that introduction of flexible modifier on the epoxy/clay interface lead to increase in the ultimate tensile strenght and elongation at break by 31% and toughness up to 83%. The electrochemical impedance spectroscopy and permeability tests proved the pronounced barrier effect of clay particles against corrosive species and water vapor when high dispersion degree of clay in NC was achieved.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Progress in Organic Coatings",
title = "Polyamidoamine as a clay modifier and curing agent in preparation of epoxy nanocomposites",
pages = "321-311",
volume = "131",
doi = "10.1016/j.porgcoat.2019.02.037"
}

Tomić, M., Dunjić, B., Nikolić, M. S., Trifković, K., Stanković, N., Pavlović, V., Bajat, J.,& Djonlagić, J.. (2019). Polyamidoamine as a clay modifier and curing agent in preparation of epoxy nanocomposites. in Progress in Organic Coatings
Elsevier Science Sa, Lausanne., 131, 311-321.
https://doi.org/10.1016/j.porgcoat.2019.02.037

Tomić M, Dunjić B, Nikolić MS, Trifković K, Stanković N, Pavlović V, Bajat J, Djonlagić J. Polyamidoamine as a clay modifier and curing agent in preparation of epoxy nanocomposites. in Progress in Organic Coatings. 2019;131:311-321.
doi:10.1016/j.porgcoat.2019.02.037 .

Tomić, Milos, Dunjić, Branko, Nikolić, Marija S., Trifković, Kata, Stanković, Nadezda, Pavlović, Vladimir, Bajat, Jelena, Djonlagić, Jasna, "Polyamidoamine as a clay modifier and curing agent in preparation of epoxy nanocomposites" in Progress in Organic Coatings, 131 (2019):311-321,
https://doi.org/10.1016/j.porgcoat.2019.02.037 . .

TY  - JOUR
AU  - Tomić, Milog
AU  - Dunjić, Branko
AU  - Nikolić, Marija S.
AU  - Maletaskić, Jelena
AU  - Pavlović, Vladimir
AU  - Bajat, Jelena
AU  - Djonlagić, Jasna
PY  - 2018
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/4750
AB  - The major aims of this paper are the investigation of the effects of the mixing procedure and the montmorillonite (Mt) surface modification on the structure (optical microscopy, XRD, TEM, SEM), rheological, mechanical properties (DMA, tensile test) and corrosion stability (electrochemical impedance spectroscopy) of clay mineral/epoxy nanocomposite (CPN). Two series of CPN samples were prepared based on diglycidyl ether of bisphenol A (DGEBA) and polyamidoamine curing agent with three organophilic Mt and sodium-montmorillonite (1 wt%). Mt were mixed with DGEBA solution in the powder (direct mixing) and in the form of dispersions, preswollen in a commercial coating thinner (solution intercalation). The commercial Mt (Cloisite 30B) modified by quaternary alkylammonium ions bearing hydroxyl groups and especially Mt functionalized by primary (HDA(+)-Mt) alkylammonium ions, at loadings close to cation exchange capacity (CRC), were significantly swollen by thinner and further uniformly dispersed into CPN. Meanwhile, low gel volumes in thinner were found for more hydrophobic Mt (Cloisite 15A). The compatibility of Mt with solvents was well described by solubility and Flory-Huggins interaction parameters. In contrast to the direct incorporation of Mt powders in CPN, swelling enhanced intercalation of epoxy matrix into Mt, and for HDA(+)-Mt based CPN interlayer spacing reached 4.4 nm. The usage of HDA(+)-Mt organoclay and solution intercalation procedure provided the highest enhancement in rheological parameters (G', G", of Mt/epoxy dispersions and glassy storage modulus, Young's modulus and barrier properties of cured CPN.
PB  - Elsevier Science Bv, Amsterdam
T2  - Applied Clay Science
T1  - Dispersion efficiency of montmorillonites in epoxy nanocomposites using solution intercalation and direct mixing methods
EP  - 63
SP  - 52
VL  - 154
DO  - 10.1016/j.clay.2017.12.047
ER  - 

@article{
author = "Tomić, Milog and Dunjić, Branko and Nikolić, Marija S. and Maletaskić, Jelena and Pavlović, Vladimir and Bajat, Jelena and Djonlagić, Jasna",
year = "2018",
abstract = "The major aims of this paper are the investigation of the effects of the mixing procedure and the montmorillonite (Mt) surface modification on the structure (optical microscopy, XRD, TEM, SEM), rheological, mechanical properties (DMA, tensile test) and corrosion stability (electrochemical impedance spectroscopy) of clay mineral/epoxy nanocomposite (CPN). Two series of CPN samples were prepared based on diglycidyl ether of bisphenol A (DGEBA) and polyamidoamine curing agent with three organophilic Mt and sodium-montmorillonite (1 wt%). Mt were mixed with DGEBA solution in the powder (direct mixing) and in the form of dispersions, preswollen in a commercial coating thinner (solution intercalation). The commercial Mt (Cloisite 30B) modified by quaternary alkylammonium ions bearing hydroxyl groups and especially Mt functionalized by primary (HDA(+)-Mt) alkylammonium ions, at loadings close to cation exchange capacity (CRC), were significantly swollen by thinner and further uniformly dispersed into CPN. Meanwhile, low gel volumes in thinner were found for more hydrophobic Mt (Cloisite 15A). The compatibility of Mt with solvents was well described by solubility and Flory-Huggins interaction parameters. In contrast to the direct incorporation of Mt powders in CPN, swelling enhanced intercalation of epoxy matrix into Mt, and for HDA(+)-Mt based CPN interlayer spacing reached 4.4 nm. The usage of HDA(+)-Mt organoclay and solution intercalation procedure provided the highest enhancement in rheological parameters (G', G", of Mt/epoxy dispersions and glassy storage modulus, Young's modulus and barrier properties of cured CPN.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Applied Clay Science",
title = "Dispersion efficiency of montmorillonites in epoxy nanocomposites using solution intercalation and direct mixing methods",
pages = "63-52",
volume = "154",
doi = "10.1016/j.clay.2017.12.047"
}

Tomić, M., Dunjić, B., Nikolić, M. S., Maletaskić, J., Pavlović, V., Bajat, J.,& Djonlagić, J.. (2018). Dispersion efficiency of montmorillonites in epoxy nanocomposites using solution intercalation and direct mixing methods. in Applied Clay Science
Elsevier Science Bv, Amsterdam., 154, 52-63.
https://doi.org/10.1016/j.clay.2017.12.047

Tomić M, Dunjić B, Nikolić MS, Maletaskić J, Pavlović V, Bajat J, Djonlagić J. Dispersion efficiency of montmorillonites in epoxy nanocomposites using solution intercalation and direct mixing methods. in Applied Clay Science. 2018;154:52-63.
doi:10.1016/j.clay.2017.12.047 .

Tomić, Milog, Dunjić, Branko, Nikolić, Marija S., Maletaskić, Jelena, Pavlović, Vladimir, Bajat, Jelena, Djonlagić, Jasna, "Dispersion efficiency of montmorillonites in epoxy nanocomposites using solution intercalation and direct mixing methods" in Applied Clay Science, 154 (2018):52-63,
https://doi.org/10.1016/j.clay.2017.12.047 . .