Epoxy resin refers to an organic polymer compound containing two or more epoxy groups in the molecule. Except for individual, their relative molecular mass is not high.
The molecular structure of epoxy resin is characterized by the active epoxy group contained in the molecular chain. The epoxy group can be located at the end, middle or in a ring structure of the molecular chain.
Because the molecular structure contains active epoxy groups, they can crosslink with various types of curing agents to form an insoluble, infusible polymer with a three-dimensional network structure.
Chengcheng Testing Center specializes in providing plastic testing, resin testing, epoxy resin testing, epoxy resin analysis, epoxy resin composition analysis, epoxy resin formulation analysis and other related test items.
Epoxy resins are generally classified according to strength, heat resistance and characteristics. There are 16 main types of epoxy resins, including general purpose adhesives, structural adhesives, temperature resistant adhesives, low temperature resistant adhesives, underwater, wet surface adhesives, conductive adhesives, Optical glue, spot welding glue, epoxy resin film, styrofoam, strain glue, soft material bonding glue, sealant, special glue, suspected cured glue, civil construction glue.
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(1) High mechanical properties. Epoxy resin has strong cohesion and dense molecular structure, so its mechanical properties are higher than general-purpose thermosetting resins such as phenolic resin and unsaturated polyester.
(2) Strong adhesion. The epoxy resin curing system contains extremely active polar groups such as epoxy groups, hydroxyl groups, ether bonds, amine bonds, ester bonds, etc., giving the epoxy cured product polar groups such as metals, ceramics, glass, concrete, wood, etc. The wood has excellent adhesion.
(3) The curing shrinkage is small. Generally 1% ～ 2%. It is one of the varieties with the smallest curing shrinkage rate among thermosetting resins (phenolic resin 8% -10%; unsaturated polyester resin 4% -6%; silicone resin 4% -8%). The linear expansion coefficient is also very small, generally 6 × 10-5 / ℃. Therefore, the volume does not change much after curing.
(4) Excellent electrical insulation. Epoxy resin is one of the best dielectric properties among thermosetting resins.
(5) Good stability and excellent chemical resistance. Epoxy resins that do not contain impurities such as alkalis and salts are not likely to deteriorate. As long as it is stored properly (sealed, protected from moisture, not exposed to high temperatures). The epoxy cured product has excellent chemical stability.
The main testing items of epoxy resin:
Gel time, water absorption, hardness, appearance, specific gravity, viscosity, heat distortion temperature, thixotropy, surface resistance and volume resistance
Related raw material testing:
Polyethylene (PE), polypropylene (PP), polystyrene (PS), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), phenolic molding compound, polycarbonate (PC), polyurethane, polyamide ( PA, also known as nylon), epoxy resin, ABS resin, polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyarylate ethylene-vinyl acetate copolymer (EVA), PPS plastic, acrylonitrile-butadiene-styrene (ABS) resin, acetal resin, polyamide 1010 resin。