ANALYSIS OF THE INFLUENCE OF THE NATURE OF THE FILLER SURFACE ON THE PROPERTIES OF HYBRID ORGANIC-INORGANIC NANOCOMPOSITES BASED ON EPOXY OLIGOMER

2021 ◽  
Vol 43 (3) ◽  
pp. 190-197
Author(s):  
V.D. MYSHAK ◽  
◽  
V.V. SEMINOG ◽  
N.V. KOZAK ◽  
◽  
...  
Keyword(s):  
Thermal Properties ◽  
Chemical Nature ◽  
Epoxy Oligomer ◽  
Sorption Process ◽  
Hydroxyl Groups ◽  
Epoxy Nanocomposites ◽  
Filler Surface ◽  
Highly Dispersed ◽  
Inorganic Nanocomposites ◽  
Epoxy Groups

The aim of this work was to investigate the influence of the chemical nature of the filler surface on the properties of hybrid organo-inorganic nanocomposites based on epoxy oligomer ED-20 in the presence of nanoscale functional filler of inorganic origin - aerosil, with different surface nature. The influence of the chemical nature of the surface of highly dispersed aerosil on the thermal properties of nanocomposites based on epoxy oligomer ED-20 has been studied. The peculiarities of the process of thermooxidative destruction have been studied. It is shown that the introduction of highly dispersed aerosil in the amount of 0.5% in the epoxy matrix does not lead to changes in the thermal properties of composites, and the nanofiller in the amount of 5% improves thermal stability of composites. The kinetics of the curing process of epoxy nanocomposites was studied by IR-spectroscopy. The influence of the presence of functional groups on the nanofiller surface on rate and the degree of conversion of epoxy groups was determined. The presence of hydroxyl groups on the surface of A-300 contributes to the rate of conversion of epoxy groups to a greater extent, compared with aerosil with a modified surface, which contains on the surface methyl groups capable of blocking reactive groups. It is established that the rate of conversion of epoxy groups in the presence of aerosil decreases in the range of ED-20 > ED-20 + A-300 > ED-20 + AM-300. The sorption properties of epoxy nanocomposites have been studied. It is established that the sorption process proceeds at a higher rate when the matrix is filled with unmodified aerosil. The mechanism of influence of the chemical nature of the filler surface and content on formation and properties of epoxy nanocomposites is discussed.

scholarly journals OLIGOMERIC SILSESQUIOXANES COMBINING AZO- AND FLUORESCENT DYES IN ORGANIC SHELL

2019 ◽  
Vol 85 (4) ◽  
pp. 71-80
Author(s):  
Mariana Gumenna ◽  
Nina Klimenko ◽  
Alexandr Stryutsky ◽  
Alexandr Shevchuk ◽  
Viktor Kravchenko ◽  
...  
Keyword(s):  
Absorption Band ◽  
Rhodamine B ◽  
Fluorescent Dyes ◽  
Hydroxyl Groups ◽  
Uv Spectrum ◽  
Absorption Bands ◽  
Organic Shell ◽  
Similar Band ◽  
Inorganic Nanocomposites ◽  
Epoxy Groups

A method for the synthesis of reactive oligomeric silsesquioxanes, combining fragments of azo dye 4-(phenylazo)phenol and fluorescent dye Rhodamine B in various proportions in an organic shell was developed. These compounds were obtained by the reaction between the oligosilsesquioxane nanoparticles consisting of a mixture of linear, branched, ladder and polyhedral structures with epoxy groups in an organic frame (OSS–Ep) and the dyes. The structure of the synthesized substances was characterized by the methods of IR and 1H NMR spectroscopy. The UV-Vis spectra of OSS–Pp–Rh in DMF solution contain absorption bands characteristic of both acidic (560 and 350 nm) and lactone (in the range of 318–326 nm) forms of Rhodamine B. The absorption band of 4-(phenylazo) phenol fragments corresponding to π−π* transition is observed at 348 nm and overlaps the absorption band of Rhodamine B at 350 nm.The intensity of the absorption bands of fragments of various dyes depends on their content in organic frame of the silsesquioxane core. The intensity of the absorption bands at 348 nm and at 560 nm increases with an increase in the content of 4-(phenylazo)phenol and Rhodamine B correspondingly.It should be noted that when using DMF as a solvent the absorption band corresponding to acidic form of Rhodamine B at 560 nm in the UV-Vis spectra of the compounds obtained is more intense than similar band in the spectrum of the original Rhodamine B. Therefore, the attachment of Rhodamine B to the silsesquioxane core of oligomeric silsesquioxanes mixture does not have a significant effect on the position of absorption maxima in the UV-spectrum and prevents dye’s fragments from converting to the colorless lactone form. In the fluorescence spectra of OSS–Pp–Rh obtained using DMF as a solvent a peak at λ max = 592 nm (λex= 520 nm) is observed. The position of the fluorescence peak and its intensity in the spectra at the same optical density of the medium practically do not depend on the ratio of fragments of 4-(phenylazo)phenol and Rhodamine B in organic frame of OSS–Pp–Rh.  The combination of two different chromophores in organic shell of the silsesquioxane core broadens the range of absorbed light and the change of their ratio allows to adjust the absorption intensity in a certain area. The presence of hydroxyl groups makes it possible to introduce the obtained compounds into the composition of polymeric organic-inorganic nanocomposites by covalent bonding.

Curing characteristics, kinetics, and thermal properties of multifunctional fluorene benzoxazines containing hydroxyl groups

2020 ◽  
Vol 138 (13) ◽  
pp. 50131
Author(s):  
Xuan‐Yu He ◽  
Ting Wang ◽  
Zhong‐Cheng Pan ◽  
Abdul Qadeer Dayo ◽  
Jun Wang ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Hydroxyl Groups ◽  
Curing Characteristics

Comparative study of single‐layer graphene and single‐walled carbon nanotube‐filled epoxy nanocomposites based on mechanical and thermal properties

2018 ◽  
Vol 40 (S2) ◽  
pp. E1840-E1849 ◽  
Author(s):  
Muhammad Razlan Zakaria ◽  
Muhammad Helmi Abdul Kudus ◽  
Hazizan Md Akil ◽  
Mohd Zharif Mohd Thirmizir ◽  
Muhammad Fadhirul Izwan Abdul Malik ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Carbon Nanotube ◽  
Comparative Study ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Mechanical And Thermal Properties ◽  
Epoxy Nanocomposites ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Layer Graphene

Erosion-wear, mechanical and thermal properties of silica filled epoxy nanocomposites

2017 ◽  
Vol 120 ◽  
pp. 42-53 ◽  
Author(s):  
J. Abenojar ◽  
J. Tutor ◽  
Y. Ballesteros ◽  
J.C. del Real ◽  
M.A. Martínez
Keyword(s):  
Thermal Properties ◽  
Mechanical And Thermal Properties ◽  
Erosion Wear ◽  
Epoxy Nanocomposites

Role of alumina filler on thermal properties of carbon-epoxy nanocomposites

2021 ◽  
Author(s):  
B.R. Lokesh Yadhav ◽  
C. Chandan ◽  
T. Raghavendra ◽  
B. Suresha ◽  
H.K. Govinda Raju
Keyword(s):  
Thermal Properties ◽  
Epoxy Nanocomposites

Study of the microstructure of low-molecular rubbers

2021 ◽  
Vol 87 (11) ◽  
pp. 26-32
Author(s):  
A. A. Pushkareva ◽  
O. A. Vozisova ◽  
M. A. Leuhina ◽  
L. L. Khimenko ◽  
A. N. Ilyin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Comparative Analysis ◽  
Low Temperature ◽  
Ir Spectroscopy ◽  
Rheological Properties ◽  
Polymer Chain ◽  
Epoxy Oligomer ◽  
Hydroxyl Groups ◽  
Structural Units

The oligomer microstructure, reflecting the configuration of the elementary units (cis-1,4-, trans-1,4-, and 1,2-) and their distribution order in the polymer chain, decisively affects the physicochemical and rheological properties of the oligomer. Parameters of microstructure-dependent transitions (glass transition) characterize the oligomer behavior under abnormal low-temperature conditions. We present the results of studying the microstructure of low-molecular rubbers. We determined the content of cis-1,4- and trans-1,4-structural links of poly-divinyl-isoprene-urethane-epoxy oligomer. The structure of polybutadiene HTPB-IV with terminal hydroxyl groups was analyzed using NMR and IR spectroscopy. A comparative analysis of the microstructure of the poly-divinyl-isoprene-urethane-epoxy oligomer and low molecular rubbers with a known content of structural units has been carried out. The obtained results can be used to obtain oligomers with the desired physicochemical and mechanical properties.

Synthesis of Epoxy Nanocomposites

2021 ◽  
pp. 225-260
Author(s):  
Tamara F. Irzhak ◽  
Vadim I. Irzhak
Keyword(s):  
Carbon Nanotubes ◽  
Functional Properties ◽  
Mutual Effect ◽  
High Reactivity ◽  
Formation Processes ◽  
Epoxy Nanocomposites ◽  
Epoxy Oligomers ◽  
Composite Formation ◽  
Curing Agents ◽  
Epoxy Groups

The formation processes of epoxy nanocomposites with carbon (nanotubes, graphene, and graphite), metal-containing, and aluminosilicate (montmorillonite and halloysite tubes) fillers are considered. A high reactivity of epoxy groups and a thermodynamic miscibility of epoxy oligomers with many substances make it possible to use diverse curing agents and to accomplish curing reactions under various technological conditions. Epoxy nanocomposites are designed to realize to the same extent the unique functional properties of nanoparticles: electric, magnetic, optical, chemical, and biological. The mutual effect of both a matrix and nanoparticles on the composite formation is discussed.

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