V. Yu. Senichev

New high-density environmentally clean polyurethane materials with binary plasticizers

Thermal and physicomechanical properties of thermoplastic polyurethane binders plasticized with mixtures of low-melting diurethanes with low-molecular-weight liquids were studied. Regular trends in the effect of components of mixed plasticizers on the properties of polyurethane thermoplastics filled with finely dispersed tungsten were revealed.

High-dense polymeric compositions based on the thermoplastic polyuretanes

The results of investigating the properties of high-dense pollution-free hybrid composites on the basis of the new type of polyurethane thermoplastics with the low-melting diurethane plasticizer are represented. The material is shown appropriate for the processing at low temperature. Strengthening of such materials is shown caused by the crystallization of the low-melting plasticizer.

Structure and properties of segmented polyurethane-ureas with dissimilar soft blocks

Structure and properties of segmented polyurethane-ureas with mixed nonpolar and polar soft segments were studied. Advantages of elastomers based on mixtures of oligobutadiene and oligoether diisocyanates in providing high strength properties combined with frost resistance are demonstrated.

Characteristics of polyether urethanes with mixed soft segments, prepared by two- and three-step procedures

A three-step procedure for preparing polyurethanes with mixed polyether segments was suggested. It involves preparation of the “inverse” prepolymer by the reaction of one of oligodiisocyanates with 1,4-butanediol taken in a double excess, followed by the reaction with the other oligodiisocyanate. Polyurethanes with alternating poly(tetramethylene oxide) and poly(propylene oxide) soft segments were prepared by this procedure. Such materials surpass polyurethanes prepared from a mixture of oligodiisocyanates in the strength and softening point of the hard phase. In contrast to poly(tetramethylene oxide) urethane, elastomers with mixed polyether segments do not crystallize.

Structure and Properties of Polyurethane-Ureas Prepared from Blends of Thermodynamically Incompatible Oligomer Diisocyanates

The structure and properties of materials based on oligo(divinyl-isoprene) and oligoether diisocyanates cured with an aromatic diamine were studied.

Tetrablock Copolymers Based on Oligoether Diols, 2,4-toluene diisocyanate, Isophorone Diisocyanate, and Methylene-bis-о-chloroaniline

Tetrablock polyurethane ureas with mixed soft segments and dissimilar hard urethane urea blocks, based on oligo(propylene oxide)diol, oligo(tetramethylene oxide)diol, 2,4-toluene diisocyanate, isophorone diisocyanate, and methylene-bis-o-chloroaniline as a low-molecular-mass chain extender were synthesized and studied. The fragmentary ordering of the polymer chains of the new polyurethane urea was proved by rheokinetic data. The structure–property relationship for the polymer was found. The new polyurethane ureas surpass in the true strength the available diblock polyurethane ureas with poly(propylene oxide) soft segments by a factor of 1.5. The strength properties of the new tetrablock polyurethane ureas only weakly depend on the strain rate varied in the range 0.56–0.006 s–1.

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.

Fast-Curing Silanized Polyetherurethane Sealants

The possibility of shortening the curing time of glue sealants based on silanized polyetherethanes has been studied. It is shown that fast-curing sealants with high physicomechanical characteristics can be obtained using the domestic commercially available SM-18 binder blended with a synthesized prepolymer based on oligoethers and diisocyanates.

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.