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About unsaturated polyester resins

What is unsaturated polyester resin?

Thermosetting resin made by dissolving unsaturated polyester in a cross-linkable monomer such as styrene.There are FRP (Fiber Reinforced Plastics) applications that are reinforced with reinforcing fibers such as glass fibers and carbon fibers, and non-FRP applications that are used without fiber reinforcement, such as casting and coating.

Characteristics of unsaturated polyester resins

  • Low resin viscosity and excellent impregnation into reinforcing fibers. Compatible with a variety of molding methods.
  • No volatile by-products during curing.
  • After curing, it has excellent mechanical properties, electrical properties, water resistance, heat resistance, and chemical resistance.
  • Excellent water and
    heat water resistance
    Applications:
    bathroom materials, kitchens
  • High strength
    and lightweight
    Applications:
    automobiles, ships
  • Can be formulated
    to be flame-retardant
    Applications:
    railway vehicles
  • Large-scale molding
    possible, excellent durability
    Applications:
    septic tanks

What is vinylester (epoxy acrylate) resin?

Thermosetting resin made by dissolving vinylester (epoxy acrylate) obtained by reacting epoxy resin with (meth) acrylic acid, in a cross-linkable monomer such as styrene. The product is used for corrosion-resistant applications such as pipes and septic tanks, and for structural components of automobiles, due to its excellent acid resistance, alkali resistance and mechanical properties.

  • Acid and alkali resistance → Corrosion resistance (corrosion-resistant tanks, corrosion-resistant linings).
  • Mechanical properties → Automobiles

Curing mechanism of unsaturated polyester resins

The curing reaction is initiated by the action of radicals generated by the decomposition of the curing agent (organic peroxide).
A radical copolymerisation reaction occurs between the unsaturated polyester (UP) and the unsaturated groups of the monomer, forming a three-dimensional network structure, leading to curing.

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