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Classification And Application Of Unsaturated Polyester Resin

Jun 17, 2020

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.;


According to its performance, it can be divided into general-purpose type, anti-corrosion type, self-extinguishing type, heat-resistant type, low shrinkage type, etc.;


According to its main purpose, it can be divided into two categories of resin for glass steel (FRP) and resin for non-glass steel. The so-called fiberglass products refer to various products made of resin with glass fiber and its products as reinforcement materials, also known as glass fiber reinforcement Plastic (referred to as FRP or FRP); non-FRP products are various products made by mixing resins with inorganic fillers or using them alone, also known as non-reinforced FRP products.


According to the specific special varieties, it includes winding resin, spray resin, RTM resin, pultrusion resin, SMC, BMC resin, flame retardant resin, food grade resin, anti-corrosion resin, air-drying resin, polaroid resin, handicraft resin, Button resin, agate resin, artificial stone resin, highly transparent resin crystal resin, putty resin, etc. 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. as FRP surface decoration.


UPR's FRP products are widely used in the following fields:


Construction field: cooling towers, cross-flow, counter-flow, jet towers, air cylinders, fans, water collectors and other accessories from 8 m3/h to 3000 m3/h. 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, warehouse filling plates, towers, chimneys, anti-corrosion grounds and anti-corrosion constructions


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.


Fiberglass crafts: urban 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 light textile products: including protective covers, grilles, dry-type transformers, transformers, high-voltage tie rods, computer rooms, electrical switches, SMC satellite antennas, copper foil plates, clothing models, ventilation ducts, sliver cans Wait.


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:


Casting crafts: including crystal crafts, various opaque 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.


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". It was not until the first synthetic phenolic resin was used in 1906 that a new era of synthetic resin was opened. In 1942, the American Rubber Company first put into production unsaturated polyester resins, and later called any unprocessed polymers as resins. But it has nothing to do with "trees".


Definition of unsaturated polyester resin


Resins are divided into two categories: thermoplastic resins and thermosetting resins.


The meltable resin that is solidified by heating, melting and cooling, and can be repeated repeatedly is called thermoplastic resin, such as polyvinyl chloride resin (PVC), polyethylene resin (PE), etc.;


After heating and curing, it is no longer reversible and becomes a solid that neither dissolves nor melts. It is called thermosetting resin, such as phenolic resin, epoxy resin, and unsaturated polyester resin.


"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. When this polymer compound contains unsaturated double bond, it is called unsaturated polyester. This unsaturated polyester dissolves In monomers with polymerization ability (generally styrene). When it becomes a viscous liquid, it is called unsaturated polyester resin (English name Unsaturated Polyester Resin referred to as UPR). Therefore, the unsaturated polyester resin can be defined as a linear polymer compound obtained by polycondensation of a saturated or unsaturated dibasic acid and a saturated or unsaturated diol dissolved in a monomer (usually styrene) Viscous liquid.


Characteristics of unsaturated polyester resin


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. Glass fiber reinforced plastics (UPR-FRP) with unsaturated resin as the substrate has the following characteristics:


1. Lightweight and high strength:


The density of FRP is 1.4-2.2g/cm3, which is 4-5 times lighter than steel, but its strength is not small, and its specific strength exceeds that of steel, duralumin and fir. This is of great significance for products that need to reduce their weight, such as aviation, aerospace, rockets, missiles, ordnance, and transportation. For example, the Boeing 747 jetliner uses 2.2 tons of FRP components on the main structure, effectively saving aircraft fuel, increasing the speed, extending the battery life, and increasing the payload.


Performance of UPR-FRP and other materials:


Material Relative density (g/cm3) Ultimate tensile strength (Mpa) Specific strength (10cm3) Tensile elastic modulus (Gpa) Specific modulus (10cm3)


UPR-FRP 1.5~1.7 352 2076.6 19.71 115.9


Steel 7.8 880 1128.2 204.16 261.7


Duralumin 2.8 457.6 1634.2 70.4 251.4


Chinese fir 0.5 70.4 1408.0 9.86 197.2


2. Good corrosion resistance:


UPR-FRP is a good corrosion-resistant material, able to withstand general concentrations of acids, alkalis, salts, most organic solvents, seawater, atmosphere, oils, and is also very resistant to microorganisms. It is widely used in petroleum, chemical industry, pesticides, medicine, dyes, electroplating, electrolysis, smelting, light industry and other fields of the national economy, playing an irreplaceable role in other materials.


3. Excellent electrical performance:


UPR-FRP has excellent insulation performance and can maintain good dielectric properties under high frequency. It does not reflect radio waves, is not subject to electromagnetic effects, and has good microwave permeability. It is an ideal material for manufacturing radomes. Using it to manufacture insulating parts in instruments, motors, and electrical products can improve the service life and reliability of electrical appliances.


Dielectric properties of UPR-FRP:


Volume resistivity (Ω cm) Dielectric strength (KV mm-1) Dielectric constant (60 Hz) Power factor (60 Hz) Arc resistance (S)


1012~1014 15~20 3.0~4.4 0.003 125


4. Unique thermal performance:


The thermal conductivity of UPR-FRP is 0.3~0.4Kcal/mh℃, only 1/100~1/1000 of metal. It is an excellent thermal insulation material. The doors and windows made of it are the fifth generation of new energy-saving building materials. In addition, the FRP linear expansion coefficient is also very small, which is close to that of general metal materials, so the connection between FRP and metal will not cause stress due to thermal expansion, which is conducive to its bonding with metal substrates or concrete structures.


5. Excellent processing technology performance:


UPR's processing technology has excellent performance, simple process, and can be formed at one time. It can be molded at normal temperature and pressure, and can be heated and pressurized. No low-molecular by-products are generated during the curing process, and a relatively uniform product can be manufactured. Due to its excellent process performance, it has been widely used in the production of handicrafts, marble-like products, polyester paints and other non-glass fiber reinforced materials in recent years.


6. The designability of the material is good:


UPR-FRP is a composite material with UPR as the matrix and glass fiber as the reinforced bone material. Both are processed into a final shape after one-time processing. So FRP is not only a material, but also a structure.


The so-called designability includes two aspects:


(1) Functional design; FRP products with various special functions can be made by selecting the appropriate UPR and glass fiber, such as: corrosion-resistant products; instantaneous high-temperature products; light transmission Plate; can be made into fire-resistant and flame-retardant products; can be made into UV-resistant products.


(2) Structural design: Various product structures can be flexibly designed according to needs, such as FRP doors and windows, FRP grids, FRP pipes, FRP tanks, FRP tanks, etc.


No material is omnipotent, and FRP is no exception. First of all, FRP has many essential differences compared to metal. For example, metal is an isotropic material, and FRP is an anisotropic material. Metal is generally divided into two stages of elastic deformation and plastic deformation under stress, while FRP is in stress. Under the action, there is generally no significant plastic deformation stage, no yield point, there is delamination during the stress process, and it is easy to break suddenly when overloaded. Secondly, the modulus of FRP is low, which is 10 times worse than that of steel. Therefore, products with high rigidity requirements must be carefully designed. Third, the heat resistance of FRP is far different from that of metal materials. So far, the long-term use temperature of FRP has been limited to less than 200℃.


Classification of unsaturated polyester resin


Classification by chemical structure


Orthophthalic unsaturated polyester resin grades such as 191, 196


M-benzene type unsaturated polyester resin grade 199


Xylene type unsaturated polyester resin grades such as 2608, 902A3, Xm-1, Xm-2


Bisphenol A type unsaturated polyester resin grades such as 197, 3301, 323


Halogenated unsaturated polyester resin


Vinyl ester resin


According to product function


General purpose resin


Heat-resistant resin


Corrosion-resistant resin


Flame retardant resin


Weather-resistant resin


High-strength resin


Gelcoat resin


SMC or BMC special resin


Special resin for injection molding, RTM, pultrusion and other molding processes.

Source:http://www.up-resin.com/

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