Sealing compositions based on butyl rubber modified by reactive oligomers

The possibility of production of hot melt type reactive sealants based on butyl rubber and silaneterminated urethane semipolymers was determined.     

Zinc–Nickel Electroplating from Alkaline Electrolytes Containing Amino Compounds

As found from polarization curves, in alkaline solutions, depending on the potential sweep rate, the action of brighteners based on a polymeric tetraalkylammonium salt (PTAS) can decrease or increase the hydrogen evolution overpotential. In the presence of Zn(II) complexes, the inhibiting action of PTAS on the cathodic hydrogen evolution increases. Some PTAS-based brighteners that ensure production of Zn–Ni alloy coatings uniform in thickness and composition from alkaline electrolytes are proposed. The degree of alloying of Zn–Ni coatings can be controlled by modifying the electrolyte with amino compounds.     

Preparation,properties, and applications of elastomeric compositions vulcanized by dinitroso-generating systems

New two-component materials of “cold” vulcanization are prepared on the basis of isoprene rubber. These materials can be used, in particular, in recipes of adhesive and sealing compositions.     

New alternative to liquid thiokol in commercial sealants

The main types of polysulfide oligomers are described. The strong and weak points of liquid thiokols are considered. The synthesis of polyester urethane thiol (AR polymer) is described. AR polymer sealants are shown to have several advantages compared with thiokol sealants. The main developments by OOO Polymix Kazan in the area of synthesized new types of thiol oligomers and derived sealants are presented.     

Effect of calcium carbonate on the properties of noncuring sealants based on butyl rubber and thermoplastics

The effect of the content, dispersity, and surface polarity of calcium carbonate on the physicomechanical and rheological properties of filled noncuring hot melt sealant formulations based on butyl rubber and various thermoplastics was examined. In the formulations based on nonpolar polymers, the cohesion strength and viscosity increase with an increase in the content and dispersity of calcium carbonate, with the strongest reinforcing effect observed with hydrophobized grades of calcium carbonate. With an increase in the polarity of the polymer base, untreated natural carbonate (chalk) becomes more efficient.     

The effect of the molecular weight of polyester on the properties of silane terminated polyurethane sealants

The properties of silane terminated polyurethane sealants produced using polyesters of different molecular weights have been studied. The relationship between the molecular weight of polyester with STP oligomer polarity, degree of swelling, and physicomechanical and adhesive properties of sealants has been established. It is shown that the polarity of oligomer and properties of sealants are reduced with increasing molecular weight of polyester.     

Stress Relaxation in Polymer-Modified Bitumens

The efficiency of BNK-40/180 bitumen modification with a blended thermoelastoplast and its components is studied by measuring the kinetics of the stress relaxation in melts. Asphaltene agglomerates are disclosed to be the main kinetic units of the stress relaxation in bitumens and bitumen–polymer compositions. The efficiency of bitumen modification with polymers is mainly affected by the solubility of the latter in the malthene fraction and their adsorption on asphaltenes. The experiments performed made it possible to estimate the behavior of modified bitumens at low shear rates corresponding to the extreme conditions of their use.     

Structure and properties of thiokol sealants modified with organosilanes

The effect of functionalized organosilanes on the properties of sealants based on liquid Thiokol NVB-2 was examined. The role of these agents in formation of the vulcanization network and of chemical bonds with the substrates was analyzed.     

Application of the acid-base approach to explain adhesive properties of modified rubber coatings

The influence of the content and composition of polymeric petroleum resins (PPRs) on the properties of incongealable sealants based on butyl rubber was studied. It was shown that the introduction of PPR B grade increases the adhesion ability of these sealants to duralumin. It was concluded that use of the acid-base approach is a good tool for explaining the nature of adhesive relationships.