Basic achievements of Department
The researchers of Department developed the methods of synthesis of initiators of radical polymerization - bifunctional azocompounds, containing amine, hydrazide, hydrazone, b-hydroxyamide and other functional groups. Diene and vinyl oligomers with the same functional groups were obtained with their use. Oligomerization of diene monomers in the non-solvent medium under the action of hydrogen peroxide was explored. The mechanism of polymerization for this process which supposes participation of polar solvent (alcohols, ketones, etc.) in the reaction of initiation was offered. This mechanism explains the influence of solvent on functionality distribution.
Oligodiene reactivity in the reactions with diisocyanates, epoxides, maleinimides was studied, and compositions, perspective for production of elastomeres, adhesives, coatings, potting compound and composite materials with fillers of a different nature were developed. Elastic coatings on the base of liquid rubbers for protection of technological equipment from influence of corrosive and abrasive solutions and pulps in chemical, shipbuilding and mining industries were created. Together with a number of the applied institutes, the methods of modification of synthetic rubbers and tire blends with liquid rubbers with end functional groups were developed. Tires passed the operating tests in which good results were shown.
The researchers of Department developed the methods of synthesis of reactive urethane-containing oligomers and a new practically important direction in oligomeric chemistry - the photochemistry initiated polymerization of oligomers and their compositions. The mechanism of the layer photoinitiated polymerization under the UV-irradiation and the influence of chemical nature of the composition components on its photosensitivity was studied. Oligourethaneacrylates, which along with reactive groups contain other, including photosensitive, groups were received. The ability of these oligomers to copolymerization with vinyl monomers under the action of heating and UV-irradiation opens wide possibilities of their practical application in different regions of engineering: for photopolymeric printing form production, coatings, optical adhesives, hybrid binders of two stage curing and other materials.
Applied developments
Department can offer the following applied developments of a different level of readiness for implementation in industry:
- technology of production of bis-structure azoinitiator with end hydrazide and hydrazone groups. Experimental party of hydrazide initiator have been produced
- resistant to hydroabrasive wear coatings for work with aggressive liquids and pulps in chemical and hydrometallurgical industry. Technology was worked through on the Experimental plant of Institute. The coatings are tested with success on the mining enterprises of Uzbekistan
- technology of production of oligodienes with end hydroxyl groups with the use of hydrogen peroxyde as an initiator. The product was earlier produced in the USSR. There is a technical documentation on building of workshop by productivity 500, 1000 and 5000 tons per year
- frost-resistant and water-resistant urethane-containing sealants, coatings, mastics, putties and adhesives for use in construction industry (roofing, floors, potting joints), road-building, municipal economy, etc. They are filled any kind of organic and mineral fillers;
- isolating materials with low dielectric permeability for open-frame encapsulating in radioelectronic industry
- modification of tire rubbers by liquid rubbers with hydrazide and hydrazone end groups with the purpose of improvement of their dynamic characteristics. There are the positive results of operating tests of tires.
Invitation to collaboration
We sincerely invite home and foreign scientists and production workers to contact us with the purpose of joint research conducting and applied developments. Such subjects, active developed in Department, can become the basis of joint projects:
DEVELOPMENT OF INITIATORS OF RADICAL POLYMERIZATION
A number of bis-structure initiators with different functional groups can be received from azo-bis-izobutyronitrile. Polymeric and oligomeric azoinitsiators on their base can be synthesized and cured with formation of polyurethane or related materials. Initiators with end hydrazide and hydrazone groups are especially perspective thanks to their very good physico-mechanical characteristics and high resistance to the hydroabrasive wear.
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HYDROGEN PEROXIDE AS INITIATOR OF RADICAL POLYMERIZATION
Presently this inexpensive and environmentally clean substance is not enough used for obtaining oligomers with end hydroxyl groups. Our developments on obtaining liquid diene rubbers showed that by the selection of the polymerization conditions and solvent oligomers of high quality with functionality near 2 can be obtained. We consider that with the use of hydrogen peroxide oligomers with end hydroxyl groups with the use of the most different monomers can be received. After the reaction of these oligomers with diisocyanates block-copolymers with various valuable properties can be obtained.
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MOLECULAR DESIGN OF POLYMERS BY MEANS ASSEMBLING OF BLOCKS CONTAINING REACTIVE GROUPS
Developed bis-strukture azoinitiators with functional groups allow to get oligomeric azoinitiators with the same end groups on the base of different monomers. Subsequent radical polymerization of other monomers under the action of these initiators allows to get block-copolymers of a different structure with various properties. In particular, by combination of carbochain (heterochain) and silicon blocks in one molecule, it is possible to save unique properties of silicon polymers (wide temperature range of exploitation, good dielectric properties, hydrophobicity, etc.) and remove their disadvantage main of which are low strength and deformation characteristics. There is a factory producing silicon materials in Ukraine, on which new silicon products can be manufactured.
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RECEIPT OF DEVULCANIZED RUBBER CRUMB AND MATERIALS WITH ITS USE
The novel method of production of devulcanized rubber crumb (DRC) with the use of a dispercer-extruder worm and rotor ("dekcher") uses the high temperature shear comminution of rubber wastes, above all worn automobile tires. DRC has a highly developed surface and allows to exchange to 90 % initial rubber in general mechanical rubber goods and to 20 % in tire blends. The machine is made in Ukraine. It wuld be very useful for the decision of the critical problem of environment contamination by rubber waste.
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USE OF LIQUID RUBBERS FOR IMPROVEMENT OF TIRE BLENDS
Wide investigations showed that liquid diene rubbers with end functional groups, especially with hydrazine and hydrazone ones, proved to be very effective additions to industrial synthetic rubbers. Such modification of tire rubbers substantially improves their dynamic properties. The broad data corpus may be to put at worker's disposal.
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OLIGOMERIC UV-CURING COMPOSITIONS
The filled photopolymeric compositions with active and homogeneous filler distribution in a polymeric matrix are intended for creation of images in polygraph and printed circuit boards, protective varnishes and paints in microelectronics and instrumental industry, in technology of decorative wares, etc. Specially chose dyes and fillers enable to regulate optical and color characteristics and create new decorative effects. Compositions were used on the enterprises of Ukraine, Byelorussia, Lithuania.
ENAMELS OF COLD CURING
The Melamine-alkyd enamels for motor industry and of surface coverage of the ML type allows to work with details in an 1 hour after laying. They contain more than 30 % of hard remainder that allows considerably to decrease their expenses.
AN UNIVERSAL APPARATUS FOR MEASURING SOLUTION PROPERTIES AT DILUTION
The universal apparatus of the wide setting for measuring solution properties at dilution is created. It can be easily automated on all cycle - from preparation of series of solutions up to endless dilution. The apparatus is very convenient for measuring properties in a broad concentration ranges and for finding characteristic values at unlimited dilution as well as for exact liquid mixture preparing. It provides a large economy of time and great reduction of intensity of labor. After procedure of certification an apparatus can be offered for the sale.
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STUDY OF POLYMERIC URETAN-CONTAINING SURFACE-ACTIVE AGENTS
The comprehensive study of physico-chemical and colloid properties of polymeric soaps of a new type is offered. The influence of urethane group which shows in water solution hydrophobic properties results in appearance of a range unexpected and useful properties.
A BURETTE WITH THE ENHANCED ACCURACY OF VOLUME MEASURING
The simple gadget of a vernier type for an ordinary glass burette is offered. It is considerable increases accuracy of volume reading at simultaneous facilitation of this procedure. Alternative application of device consists in marking more rare shading on a burette without reduction (or even increase) of accuracy of volume measuring.
