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Introduction of unsaturated polyester resin

Jun 06, 2020

The unsaturated resin refers to a polymer compound containing an unsaturated double bond produced by a polycondensation reaction of a dibasic acid and a diol. The earliest resins discovered by humans are fats extracted from the secretions of trees, such as rosin, etc. This is why there is a "tree" before "fat". "Polyester" is a class of polymer compounds containing ester bonds distinguished from resins such as "phenolic" and "epoxy". This polymer compound is produced by polycondensation reaction of dibasic acid and diol, and when this polymer compound contains unsaturated double bond, it is called unsaturated polyester. This unsaturated polyester dissolves It is called unsaturated polyester resin when it becomes a viscous liquid among monomers with polymerization ability (generally styrene).

Therefore, the unsaturated polyester resin can be defined as a linear polymer compound containing unsaturated dibasic acid or glycol formed by polycondensation of a dibasic acid and a diol dissolved in a monomer (usually styrene) and Into a viscous liquid. Unsaturated polyester resin, which accounts for 75% of the resins we use every day.

Because the unsaturated polyester resin is a thermosetting resin, when it is under the action of heat or initiator, it can be cured into an insoluble and insoluble polymer network polymer. However, this polymer has very low mechanical strength and cannot meet most of the requirements. When reinforced with glass fiber, it can become a composite material, commonly known as "glass fiber reinforced plastics" (English name Fiber Reinforced Plastics referred to as FRP). The mechanical strength of "FRP" and other aspects have been greatly improved compared with the resin casting body.

Unsaturated polyester resins are classified according to specific special varieties including winding resin, spray resin, RTM resin, pultrusion resin, SMC, BMC resin, flame retardant resin, food grade resin, anti-corrosion resin, air-drying resin, Polaroid board Resin, handicraft resin, button resin, agate resin, artificial stone resin, highly transparent resin crystal resin, putty resin, etc.

Unsaturated polyester resin is used as anti-aging flame retardant gel coat, heat-resistant gel coat, spray gel coat, mold gel coat, non-cracking gel coat, radiation-curing gel coat, high wear-resistant gel coat, etc. for FRP surface decoration.

According to the structure of unsaturated polyester resin, it can be divided into o-benzene type, m-benzene type, p-benzene type, bisphenol A type, vinyl ester type, etc.;

Unsaturated polyester resin can be divided into general-purpose type, anti-corrosion type, self-extinguishing type, heat-resistant type, low shrinkage type, etc. according to its performance;

Unsaturated polyester resins can be divided into resins for glass steel (FRP) and non-glass resins according to their main uses. The so-called glass fiber reinforced plastic products refer to various products made of resin with glass fiber and its products as reinforcing materials, also known as glass fiber reinforced plastics (referred to as FRP or glass steel); non-glass fiber reinforced plastic products are resins mixed with inorganic fillers or themselves Various products made using it are also called non-reinforced fiberglass products.

Application fields of unsaturated polyester resin

Construction field: cooling towers, cross-flow, counter-flow, jet towers with 8m3/h-3000m3/h, jet towers, air cylinders, fans, water collectors and other accessories. Doors, windows, light-weight buildings, grilles, mobile homes, cold storage, park kiosks, platforms, newsstands, etc.

Anti-corrosion products and projects such as glass steel tubes, tanks and troughs: including large, medium and small caliber pipes, pipe fittings, valves, storage tanks, storage troughs, grilles, silo filling plates, towers, chimneys, anti-corrosion ground and architectural anti-corrosion, etc.

FRP vehicles: train double-decker buses and parts, window frames, car bodies, bumpers, train vents, spring plates, etc.

FRP boats: including yachts, lifeboats, transportation boats, fishing boats, speed boats, sampans, breeding boats, assault boats, etc.

FRP amusement equipment: including large amusement machines, large water parks and children's parks.

FRP transportation equipment, labor protection and security supplies: including road signs, road signs, footbridges, lamps, cable boxes, measuring scales, helmets, kiosks, explosion-proof equipment, manhole covers, etc.

Glass fiber reinforced plastic sanitary equipment: bathtub, washstand, toilet, mirror frame, overall toilet, trash can.

Energy-saving fiberglass products; including axial fans, centrifugal fans, solar water heaters, wind turbines, etc.

FRP food container: high water tank, food transportation tank, beverage tank.

FRP city sculptures, fonts, crafts and bone-bonding crafts.

FRP furniture: including seats, fast dining tables, complete sets of furniture, telephone booths, counters, etc.

FRP electromechanical, mining, and textile products: including protective covers, grilles, dry-type transformers, transformers, high-voltage rods, computer rooms, electrical switches, SMC satellite antennas, mannequins, ventilation ducts, sliver cans, etc.

Fiberglass sports equipment and music and dance equipment: including tennis rackets, parallel bars, horizontal bars, springboards, rowing boats, props, etc.

UPR's non-FRP applications are roughly as follows:

Including crystal crafts, opaque various crafts, etc.

Buttons: various polyester button products.

Artificial stone: including artificial marble, artificial agate, artificial granite, etc.

Coating: including furniture coating, piano, TV, radio shell, sewing machine table and bicycle cover varnish.

Putty: Polyester putty for car repair, etc.

Others: including anchoring agent, electrical casting, toughening agent, adhesive, etc.