Tea Datashvili

Becton, Dickinson and Company (BD) | BD · BD Medical

We have created inorganic-organic hybrid composites and antibiocorrosive coatings based on an epoxy modified with silicon-containing polyepoxies and bioactive coordination compounds. The scratch resistance was determined using a conical diamond indenter with linearly increased load. Repetitive scratching along the same groove (sliding wear determin...

In 1920, the Nobel laureate Hermann Staudinger recognized that natural and man-made polymers are produced according to the same blueprint: a very large number of small monomer molecules are linked together to produce high-molecular-weight macromolecules (Staudinger, Ber. Deutschen Chem. Ges. 53:1073–1085, 1920).

The goal of the work was improvement of mechanical and tribological properties of high density polyethylene (HDPE) while finding use for wood sawdust (wood flour). Two chemical modification methods have been used for wood sawdust treatment to improve compatibility between the HDPE matrix and wood sawdust. Traditional silane coupling was used as a f...

Quantitative "structure-properties" relationships (QSRR/QSAR) based on experimental data for the construction of models of dependences of the physical properties of bioactive nitrogen-containing compounds with bioactive spatial carbocyclic groups on molecular structures were studied. Several sets of molecular descriptors were used. The presence of...

This book introduces the most recent innovations in natural polymer applications in the food, construction, electronics, biomedical, pharmaceutical, and engineering industries. The authors provide perspectives from their respective range of industries covering classification, extraction, modification, and application of natural polymers from variou...

The effects of octadecylamine functionalised reduced graphene oxide (FRGO) on the frictional and wear properties of diglycidyl ether of bisphenol A epoxy are studied using pin on disc tribometry. The nanocomposites are prepared by adding 0.1, 0.2, 0.5 and 1.0 wt-% of FRGO to the epoxy. The addition of FRGO increases by more than an order of magnitu...

Carbon nanotubes (CNTs) and sepiolite (SEP) were modified in order to improve their compatibility with the polypropylene (PP) matrix. Carboxylic groups were introduced into the CNTs through an oxidative treatment and aliphatic chains were incorporated on SEP by ion exchange of a cationic surfactant. Maleic anhydride grafted polypropylene (PPgMA) wa...

Thermoelectric (TE) devices, both TE generators (TEGs) and TE coolers (TECs), have short service lives as TE materials undergo degradation from sublimation, oxidation and reactions in corrosive environments at high temperatures. We have investigated four high-temperature polymers (HTPs) as candidates for TE element coatings and/or TE device fillers...

This work is part of a program on composites used in thermoelectric devices. Tribological properties of dynamic vulcanizate blends of polypropylene and ethylene-propylene-diene rubber filled with 5 wt% of microscale powder have been studied. The microscale thermal-shock-resistant ceramic filler contains α-Al2O3, mullite (3Al2O3 · 2SiO2 or 2Al2O3SiO...

Biodegradation of synthetic and natural materials by various microorganisms affects a wide range of industrial processes and techniques. One of the modern ways to protect of the synthetic and natural materials from the action of aggressive microorganisms is a creation of novel antibiocorrosive covers with high bioactivity and multivectorial and dir...

We have created hybrids of functionalized single wall carbon nanotubes (fSWCNTs) and also multiwall CNTs (fMWCNTs) with PBT/PTMO, a block copolymer of semicrystalline poly(butyl terephthalate) (PBT) with amorphous oxytetramethylene (PTMO). For both single wall (SW) and multiwall (MW) carbon nanotubes (CNTs) tensile modulus and strain at break as a...

The effectiveness of reinforcement of a polymer is known to depend on the strength of the interfaces between the reinforcement and the matrix. We have used polystyrene and a styrene– butadiene–styrene (SBS) copolymer as matrixes and ceramic boehmite c-AlO(OH) as reinforce-ment. We have applied boehmite both untreated and treated with sulphonic acid...

Chitosan is an amino polysaccharide found in nature, which is biodegradable, nontoxic and biocompatible. It has versatile features and can be used in a variety of applications including films, packaging, and also in medical surgery. Recently a possibility to diversify chitosan properties has emerged by combining it with synthetic materials to produ...

We have decided to investigate whether addition of nickel (Ni) to a thermoplastic elastomer (TPE) will make TPE properties better for demanding applications. We have found that Ni particles moved well during low (100°C) temperature blending, with the polymer providing more uniform particle dispersion. In contrast, at 160°C, lower viscosity prevente...

Dynamic vulcanizate blends of polypropylene (PP) and ethylene–propylene-diene rubber (EPDM) were filled with 5wt% of micro-scale ceramic powder. To overcome the difficulty of particles dispersion and adhesion, the filler was modified through grafting using three kinds of organic molecules. A combination of Raman data with thermogravimetric analysis...

Steel fibers change the properties of hardened concrete significantly. However, addition of fibers to fresh concrete results in a loss of workability. Self-compacting concrete (SCC) is an innovative concrete that is able to flow under its own weight, completely filling formwork and achieving full compaction without vibration. We have studied compos...

We have investigated two thick film copper compositions used in thermoelectric device fabrication. Dynamic mechanical analysis, thermal mechanical analysis, tensile testing, Vickers microhardness, optical microscopy and scratch testing were performed. The small grain samples have much smaller microindentation areas and much higher hardness than lar...

Polyethylene is already one of the most commonly used polymers due to its solvent resistance and easy processing. Low-density polyethylene (LDPE) also has excellent flexibility and resilience. However, the mechanical properties of LDPE are often poor. We added the inexpensive ceramic filler Boehmite to LDPE, simultaneously improving mechanical prop...

Mechanical and tribological behavior of several dynamic vulcanizate blends of polypropylene (PP) with ethylene-propylene-diene rubber (EPDM) was examined and compared with those of uncrosslinked blends. Vulcanization was performed using two types of organic peroxides combined with (meth)acrylate coagent. The effect of different types and concentrat...

Wood is a structural material outperforming all other materials combined in the total annual tonnage used worldwide. We point out the role of wood in the development of 'green' technologies. To provide a perspective, we discuss forests and woodlands in the past and their role in the growth of civilization. Wood structure is explained. The role of w...

A novel method of isolation of polycyclic aromatic hydrocarbons (PAHs) from three Georgian petroleum fields has been developed. PAHs are classified as carcinogenic compounds and monitored worldwide in a wide range of environments including drinking water, waste water, furnace emissions, soil, hazardous waste extracts and in air over major cities. O...

In previous work crosslinked copolymers were prepared from cinnamoyloxy ethyl methacrylate (CEMA) and several monomers feed ratios of octadecyl acrylate (ODA). Networks so produced are both flexible and porous; we now report their swelling efficacies as a function of temperature in toluene and in crude petroleum. Network characteristics is presente...

Effect of interfacial interactions on mechanical properties of composites of low-density polyethylene reinforced with micrometric Boehmite powders were studied in combination with two silane coupling agents vinyltri(2-methoxyethoxy)-silane (VTMES)-SCA 972 and 3-(trimethoxysilyl)-propylmethacrylate (3MPS)-SCA 989. Samples were prepared via melt mixi...

Various amounts of nano size silica particles prepared by a sol-gel process were added to epoxy+ amine systems. We have investigated tribological properties including friction and sliding wear resistance of hybrids so obtained, and also relationships between different tribological properties and surface topography. The thermal degradation behavior...

Tribological properties of composites of low density polyethylene (LDPE) reinforced with 1, 5, 10, 20 wt% micrometric Boehmite (B) and/or preheated Boehmite (HB) powders were studied in combination with two silane coupling agents (SCAs): vinyltri(2-methoxyethoxy)-silane (VTMES)-SCA 972 and 3-(trimethoxysilyl)-propylmethacrylate (3MPS)-SCA 989. When...

Poly(methyl acrylate) (PMA) + SiO2 composites were synthesized via a sol-gel reaction. The base acrylic copolymers with a content of alkoxysilane groups were prepared by co-polymerization of methylacrylate (MA) with 3-(trimethoxysilyl) propylmethacrylate (3MPS) or vinyltrimethoxysilane (VTMS); the products were cocondensed with tetraethylorthosilic...

Polymerizable organic silane molecules 3-(trimethoxysilyl)propylmethacrylate (3MPS) and vinyltri(2-methoxyethoxy)silane (VTMES) have been introduced onto surfaces of high purity Boehmite (a commercial alumina) via hydroxyl groups on the oxides in order to obtain organic-inorganic hybrid “macromonomers”. Changes of surface characteristics have been...

Tribological properties of blends of melamine-formaldehyde resin (MFR) with low density polyethylene (LDPE) containing 1, 5, 10, 20, 25 wt% MFR were investigated. We have determined sliding wear by multiple scratching along the same groove using a micro scratch tester. Instantaneous penetration depth is lowered by the MFR addition to LDPE. However,...

From economical point of view wear is of the most important aspects of viability of an industrial enterprise. Mobile components in structures undergo wear and need to be replaced. This is particularly important for polymer based materials (PBMs). New methods have to be developed for wear mitigation in PBMs. Several such methods are under investigat...

Blends were prepared using a Brabender preparation station and compression moulding. Characterisation included differential scanning calorimetry ( DSC), thermogravimetric analysis ( TGA), Fourier transform infrared spectroscopy ( FTIR), environmental scanning electron microscopy ( ESEM) and atomic force microscopy ( AFM). Thermal analysis, AFM and...

UV curable, hard and transparent hybrid inorganic-organic coatings with covalent links between the inorganic and the organic networks were prepared using organically crosslinked heteropolysiloxanes based on the sol-gel process. The materials were applied onto polyester sheets and UV cured. The deposition was followed by a thermal treatment to impro...

Melamine + formaldehyde resin (MFR) was synthesized and blended with a low density polyethylene (LDPE). Tribological, thermal and morphological properties of LDPE + MFR blends containing 1, 5, 10, 20, 25 wt. % MFR were investigated. After preparing the blends with a Brabender preparation station and a compression molding machine, the following prop...

The process of isolation of C5-C10 n-paraffins from the straight-run gasoline fraction of the Samgori (Georgia) commercial oil on the CaA zeolite (adsorbate composition, degree of recovery) was studied depending on various factors: the adsorption temperature, feed space velocity, desorption pressure, and feedstock : adsorbent mass ratio. It was fou...

The process of isolation of individual (C3-C8) n-alkanes from close-cut fractions of straight-run gasoline of the Samgori (Georgia) commercial oil on the CaA zeolite was studied. The possibility of obtaining n-pentane, n-hexane, n-heptane, and n-octane with a purity of 98.4-99.7 wt% was shown. It was found that the purity of n-alkanes obtained comp...