Papers by Keyword: Butyl Rubber

Abstract: The article compiled a mathematical model of the cationic copolymerization of isobutylene and isoprene using a catalyst AlCl3 in a CH3Cl solution, including the reactions of initiation, chain growth, chain transfer to the monomer, and chain termination. The molecular weight characteristics of butyl rubber synthesized in methyl chloride using a catalytic system based on aluminum trichloride have been investigated. Relationships are obtained for calculating the moments of the molecular weight characteristics of butyl rubber. The effect of the concentration of the initiator on the conversion versus time was investigated.

Abstract: The paper uses waste from the production of synthetic rubbers, industry, various clays for effective ways to solve the socio-economic and environmental problems of preserving natural resources and preventing environmental pollution. The construction materials industry faces the most important task-the search for non-deficit raw materials that allow partially or completely eliminate expensive conditioned polymers, rubbers and obtain cheaper mastic roofing materials while maintaining their high physical, mechanical and operational properties. Thermomechanical curves of composite materials based on synthetic rubbers with additives were studied. It is shown that the softening of samples of roofing materials No. 325 and No. 326 begins at , 20 % deformation is achieved, respectively, at – (No. 325) and + (No. 326), a sharp increase in deformation is observed, respectively, with a loss of strength: 40 % (No. 325) and 20 % (No. 326). Based on these materials, reinforced mastic roofs have been developed, which have low values of crack resistance. The coefficient of water resistance depends on the base, i.e. the reinforcing materials.

Abstract: Experimental studies on the effect of frequency and temperature on the dynamic mechanical properties of filled composites are studied poorly and require further research. The purpose of theresearch is to study the effect of heavy fillerbarite (BaSO₄), on the dynamic characteristics of a highly filled composite based on butyl rubber, and to compare the efficiency of barite in the composite with similar light filler. The conclusions are made on the basis of a comparative analysis of the temperature-frequency dependences of the loss tangent and the storage modulusat various percentages of filler, obtained by the DMA method. It has been established that while increasing barite concentration the elasticity of the composite material decreases, the glass transition temperature shifts upwards, and the reverse occurs in the zone of highly elastic state of the composite: the higher the barite concentration, the higher the damping properties. The authors provided a rationale that the heavy filler shows the effect only in the highly elastic zone if compared with the light one. The article is of practical value for the development of new vibration insulation materials.

Abstract: The characterization of microstructure and basic properties of domestic butyl rubber 1751 ( IIR 1751) was performed with different testing , such as 1H-NMR spectrum, gel permeation chromatography, dynamic mechanical analysis, thermal gravimetric analysis and differential scanning calorimeter. And the comparison with Butyl 268 and Butyl 301 was made. The results showed that IIR1751 had a narrower molecular mass distribution, lower number-average molecular mass and lower weight-average molecular mass. The unsaturation degree of IIR1751 was close to Butyl 268 and Butyl 301. Its thermal stability was higher than the other and its ash content and volatile matter content was lower. Its glass transition temperature was same to Butyl 268’s, which was slightly higher than the Butyl 301. Dispersion of carbon black in IIR1751 vulcanizates was poor, but IIR1751 vulcanizates had good processing property, had a longer scorch safety period and fast curing rate. Its fatigue performance was good and its mechanical properties can achieve a better balance.

Abstract: Butyl rubber was synthesis by solution process in hexane-chloromethane mixed solvent using ethylaluminium sesquichloride/water as initiating system The product has comparable properties with BK1675(solution process) and EXXON268（slurry process）in terms of molecular, molecular distribution, unsaturated degree as well as processing properties of Mooney viscosity, vulcanization, tensile properties. The solution method will open up a new way to produce butyl rubber in China.

Abstract: The carbon fibers / rubber composite films were fabricated by compression molding method with butyl rubber (IIR) as matrix and carbon fiber as reinforced material. The mechanical properties and electromagnetic shielding effect of the thin films at different conditions were measured by the WDW electronic universal testing machine according the national standard GB13022-91 and the far-field EMC shielding effectiveness test fixture (DN1015 type) respectively. The results show that the good mechanical properties of composite films with mess ratio of IIR and carbon black of 1:6 and vulcanizing time of 1.5h were obtained at the same other condition that the tensile strength reached 534.65MPa, the elongation rate reached 87.26% and the yield point stress up to124.85MPa. Meanwhile, it is also found that the electromagnetic shielding effect of the thin films shows negative growth at low frequency area ranging from 1MHz to 300MHz. Whereas, the shielding effect increases with frequency at 300MHz ~ 1.5GHz, and the SE value is up to -25dB ~-35dB.

Abstract: Scaling of the real and the imaginary part of dynamic moduli with frequency, for fully cured elastomer materials as gum and active carbon black filled butyl rubbers, is considered experimentally and theoretically. For gum rubber in different ranges of frequency complete agreement with G''-scaling predicted by the Rouse theory is obtained. Obtained slopes for all G' and G'' of filled rubber are much lower.