The correspondence of detachment characteristics and acid-base interaction measures

A quantitative estimate for the intensity of interphase acid-base interactions is proposed based on the acid and base parameters of the free surface energy of polymer adhesives and substrates of a different nature. An interaction between acid-base and strength characteristics of adhesive compounds is established. An increase in the adhesive strength with an increase in the difference between the surface acid and base properties of connected materials is revealed for a number of compounds (polyolefine-metal, rubber mixtures-brass, and Thiokol compounds-glass).     

Influence of the nature of a curing agent on the peculiarities of formation of vulcanization networks in polysulfide sealants

The molecular mobility of vulkanizates of liquid thiokols cured with various vulcanizing agents was studied by the NMR method in a wide temperature interval. The influence of the nature of vulcanizing agents and the structure of the forming vulcanization network on the change in the character of molecular mobility in vulcanizates of polysulfide oligomers was established. The correlation of effective (υ_eff) and chemical (υ_ch) densities of vulcanization networks of thiokol sealants with parameters of the NMR spectrum of the latter was found. The influence of the nature of a curing agent on the peculiarities of the formation of vulcanization networks of polysulfide oligomers is discussed.     

Modification of siloxane rubber with aminoethers of boric acid

A modifying effect of amino esters of boric acid on polydimethyl/methylvinyl siloxane caoutchouc and resin based on them was studied. It is shown that small amount of this type of modifying agent leads to a marked increase in viscosity of the compositions, and improved mechanical and thermal properties of the vulcanizates. With increasing the amount of the modifying agent they begin to show properties of a plasticizer.     

Influence of maleic anydrate on properties of incongealable sealants based on butyl rubber

The possibility of using butyl rubber modified by maleic anhydrate as an adhesive additive and obtaining incongealable composites on its basis are shown.     

The possibility of using radiation-reclaimed butyl rubber in the building industry

Studies are performed to demonstrate the possibility of the valuable replacement of butyl rubber by a radiation-induced degradation product for the production of different waterproofing and roofing materials in the building industry. The efficiency of using nitroso compounds, such as p-dinitrobenzene and quinol ether, as vulcanizing agents is investigated. It is shown that a reclaimed product obtained at an irradiation dose of 20 Mrad may be used as an efficient adhesive additive. The addition of such a reclaimed product to a solution-born mastic in an amount of 30 mass parts per 100 mass parts of rubber substantially enhances the adhesion to concrete, steel, polyethylene, etc. other properties remaining unchanged.     

Properties of Bitumens Modified by Thermoplastic Elastomers

The possibilities of modification of bitumens by blend thermoplastic elastomers (TPEs) with predominantly maximum long main chains are studied. The evaluation of their properties shows that the blend TPEs display a stronger effect in low-viscosity bitumens, which is associated with improved compatibility of TPEs in bitumens, as evidenced by convergence of the solubility parameters of TPEs and of the aliphatic part of the malthene fraction of bitumens. The relaxation properties of the modified bitumens allow us to judge their stability under operating conditions, to evaluate this effect quantitatively, and to determine the activation energy of the relaxation process.     

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.     

The influence of thixotropic additives on the properties of sealants based on oligoester urethane thiol

The influence of thixotropic additives on the viscosity and thixotropy of sealants based on oligoester urethane thiol was examined. It was found that the fumed A-175 silica aerosil is the most efficient as a thixotropic additive for the sealants based on oligoester urethane thiol. The introduction of glycols along with the aerosil or hydrated silicon dioxide makes it possible to vary widely the viscosity and thixotropy of the sealant compositions based on oligoester urethane thiol.