The method of obtaining calcium polysulfide solutions by the interaction of calcium oxide and sulfur in a solvent, characterized in that, in order to intensify, reduce the reaction temperature and increase the yield of the target product, the process is carried out with a continuous flow of hydrogen sulfide gas into the solution at a temperature of the reaction mass of 50-80 ° C.Подробнее
The composition for producing sulfur concrete, containing quartz sand and a composition of elemental sulfur and sulfur modifier previously prepared at 140 ° C, characterized in that it contains quartz sand, 70% of which is milled, and as a modifier of sulfur - polyorganopolysulfide with unsaturated carbon-carbon bonds in the organic radical correspondingПодробнее
The plasticizer for PVC compositions, which is a mixture of esters with a predominant content of terephthalic acid 2-ethylhexyl ester, characterized in that, to obtain a plasticizer, a terephthalic acid, previously dried by azeotropic distillation, is watered as a source of terephthalic acid and an alcohol fraction - a by-product of terephthalic acid and an alcoholic fraction, obtained by distillation of the bottoms of the distillation of 2-ethylhexanol at a pressure of 10-20 mm Hg. and a vapor temperature of 145-185 ° C.
The method of producing a dioctyl terephthalate plasticizer, which includes the esterification of terephthalic acid with 2-ethylhexanol in the presence of a titanium alkoxide catalyst with a further solvent distillation, characterized in that technical terephthalic acid, which is a semi-product of the production of purified terephthalic acid, is used as a raw material, while the reaction mass containing a suspension of technical terephthalic acid and 2-ethylhexanol in a mass ratio of 1: 1.7 ÷ 2.8, is boiled at a temperature of 180 ÷ 200 ° C with simultaneous distillation of the azeotropic mixture of 2-ethylhexanol and water until the complete cessation of water release, then the solvent is distilled off at a temperature of 100 ÷ 195 ° C and a vacuum of 16 ÷ 20 mm Hg.Подробнее
The method of alkaline hydrolysis of polyethylene terephthalate (PETP) waste with obtaining terephthalic acid, including the hydrolysis of PETP with sodium hydroxide in a solvent when heated, followed by adding water to the reaction mass until complete dissolution of the formed disodium salt of terephthalic acid, separation of the aqueous layer from the solvent, precipitation of terephthalic acid from the aqueous solution of concentrated hydrochloric acid followed by filtration, washing and drying of terephthalic acid, characterized in that a cheap by-product of flotoreagent oxal T-92 is used as a solvent for alkaline hydrolysis, while PETP waste is used in flakes of 3-5 mm in size, reagents are taken in a PETP: NaOH: flotation reagent oxal T-92 = 1: (0.5-0.8) :( 4-6) and the process of hydrolysis is carried out at a temperature of 130-150 ° C and atmospheric pressure for 3-5 hours.Подробнее