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 Home > Production > By product groups > Saturated and unsaturated polyester resins > Saturated polyester resins (polyols)
Saturated polyester resins (polyols) Polyesters containing active hydroxyl groups - OH which are normally called “polyols” form a separate group. They are used as a base raw material in production of foamed polyurethanes, epoxy resins, resins for paint-and-lacquer materials. Properties of the products, their application and processing methods depend both on composition and structure of the polyesters and on the composition and structure of the compounds with which they react to produce final products. Foamed polyurethanes are formed by the reaction between NCO- and OH- groups. NCO-group carriers are isocyanates , OH-group carriers are polyols. Chemical reaction starts when isocyanates and polyols are mixed; reaction rate is dependant on the catalyst. This chemical reaction is exothermic. During the reaction the material is foamed due to intensive evaporation of low-boiling compounds pre-introduced into the system. The process is optimized by qualitative and quantitative selection of catalytic additives. Thus, foamed PU process includes the following stages: preparation of feed mixtures, mixing, casting the reactive composition into the mold or compressed-air spraying on a prepared surface. The following key points are fixed during foamed PU formation: - starting time Tstart – time from start of the mixing to beginning of the foaming; - gelation time Tgel – time during which the foaming mass becomes gelled and stops being flowing; - growth time Tgrowth – time from the start of mixing to the moment when volume of the foaming mass stops to increase- density at free foaming. To date “Khimpostavschik” has developed various grade polyols to produce goods from rigid foamed PU by molding, spraying, and injection which are widely used in all areas of the construction industry. They are light but sufficiently strong foamed plastics which are characterized by very low thermal conductivity, low permeability, good adhesion to paper, metal, wood, plaster, and ruberoid. Major applications of rigid foamed PU in civil construction are: insulation of cooling chambers, pipelines, walls, roofs, basements, ceilings, residential and industrial premises, saunas, baths; manufacture of isothermal and refrigerator vans, chambers, sandwich panels, insulation blocks for various applications; sealing of panel joints in houses / of door and window openings. Rigid foamed PU is also used for rock reinforcement, in production of pre-formed insulation and pre-insulated pipes.
“Khimpostavschik” has mastered technology of production of polyol to be used in manufacture of goods from filled foamed PU. These goods are distinguished by high mechanical strength (compression breaking strength is 8,5 kgf/cm2), high heat resistance without any significant sacrifice in heat insulation properties. Use of cheap fillers allows to significantly bring down cost of the goods. Low density of the product (150 kg/m3) and good mechanical strength permit to characterize this material as a new type construction material for civil construction and for use in production of dies.
The grades mentioned below are freon-base polyols. Currently we are developing carbon dioxide type grades.
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Saturated and unsaturated polyester resins |
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