E. R. Volkova

Polyurethane adhesive composition cured at room temperature

The influence of polyfunctional hydroxyl-containing oligomer on the rheological, physicomechanical, and adhesive properties of polyurethane composite based on multicomponent oligomer blend and polyisocyanate is investigated. The kinetics of curing is investigated by the viscometric method, and the composition lifetime is determined. It is shown that the polyurethanes under investigation can be used as fast-curing adhesive composites of cold curing operating in a temperature interval of up to +90°C.

Elastic and moisture-resistant compounds based on mixtures of oligotetraurethane diepoxide, epoxy-diane resin, and aromatic diamine

Elastic and cold-resistant compounds based on oligodiene tetraurethane diepoxide and ED-20 epoxy-diane resin were obtained. The structure of compounds formed upon curing of the reaction mixture with aromatic diamine was studied. The advantages of new compounds in terms of physicomechanical and adhesion properties compared to a compound containing no ED-20 resin are demonstrated.

Processes of mass transfer of low-molecular-weight liquids in crosslinked elastomers

Experimental and theoretical works devoted to the study of diffusion phenomena of the transfer of plasticizers and organic solvents in polymeric materials are reviewed. Current theoretical models describing diffusion processes in deformed solids and polymeric materials are analyzed from the viewpoint of their ability to describe the transfer of plasticizers in elastomers. Current notions of mass transfer processes in crosslinked elastomers are supplemented by results obtained in recent years.

Preparation and Properties of Frost-Resistant Room-Temperature-Curable Compounds Based on Oligoethertetraurethane Diepoxides of Various Chemical Structures

New polytetraurethane diepoxides were prepared from oligo(tetramethylene oxide)diols of various molecular masses, various diisocyanates, and glycidol. High-strength frost-resistant cold-curable elastic compounds were prepared on their basis. The use of aminoethylpiperazine as a curing agent allows the cured materials to be prepared in 24 h at room temperature. The elastomers based on isophorone diisocyanate exhibit higher mechanical and thermal characteristics than those based on 2,4-toluene diisocyanate, which is due to higher degree of microphase segregation of soft and hard blocks of elastomers based in isophorone diisocyanate.

The Effect of the Isocyanate–Hydroxyl Ratio on the Structure and Properties of Hard Polyurethanes

A comprehensive study has been carried out of the structure and rheological and physicomechanical properties of low-temperature curing polyurethane compositions based on polyisocyanate and a blend of hydroxyl-containing oligomers of different reactivity. The maximum curing rate and strength parameters (tensile strength and Young’s modulus) have been shown to be achieved at the ratio of the reacting groups NCO : OH = 1.1.

Influence of the molecular mass of soft segments on the thermodynamic stability and physicomechanical properties of plasticized polyether urethane

The physicomechanical properties and thermodynamic stability of segmented polyether urethane containing poly(tetramethylene oxide) segments of different molecular masses (М ∼ 1000, 1400, 1950) and plasticized with di(2-ethylhexyl) sebacate were analyzed in relation to the molecular mass of the soft segments, and the glass transition point of the soft phase of the polymer was determined. Based on the results obtained, a rapid method was suggested for experimental determination of the osmotic pressure (up to ∼1000 kPa) in the polymer–plasticizer system. The possibilities of preparing thermodynamically stable plasticized materials of high strength (up to 22–26 MPa) with the glass transition point as low as–95 to–100°С were demonstrated.

Effect of plasticization on the stability of the physicomechanical properties of polyetherurethane in a humid medium

The moisture uptake by segmented poly(tetramethylene oxide)urethanes with different content of a low-polarity plasticizer, di(2-ethylhexyl) sebacate, and the mechanical behavior of these materials in a humid atmosphere were studied. Plasticization appreciably improves the physicomechanical properties and frost resistance of the microheterogeneous polyurethane. The modification of the polyetherurethane by the low-polarity plasticizer is advantageous for ensuring high strength characteristics of the elastomer in a humid atmosphere. The extent of recovery of the polyurethane properties on drying was estimated. The polyurethane plasticized with di(2-ethylhexyl)sebacate can be used in items operated in highly humid air.

A high-strength technological compound on the basis of oligobutane diendiol, isophorone diisocyanate, and aromatic diamine

Abstract2,4-Toluene diisocyanate is substituted with isophorone diisocyanate during the synthesis of polybutadiene urethane urea. The obtained polydiene urethane urea is shown to be superior to the physicomechanical and rheological properties of the traditional material synthesized with the use of 2,4-toluene diisocyanate. It is established that polybutadiene urethane urea is more than twice as good as steel adhesion to polydiene urethane epoxy compounds.

Studies of elastomer swelling process in liquid mediums

The diffusion kinetics of the absorption of organic solvents in the system of a layer of boundedly swelling material joined with hard, warp-free foundation has been studied. It has been shown that the system can be used for the theoretical and experimental study of strain behavior of polymeric coatings in contact with physically aggressive media.