VINIL ESTER RESINS
1. Chemical Definition
Vinil Ester Resin are thermosetting resins that consist of a polymer backbone with an acrylate (R=11) or methacrylate (R= CH3) thermination R-(-O-C-C=C) Although viny ester resin have sometimes been classified as polyesters, they are typically diesters that (depending on the polymer backbone) contain recurring ether linkage.
The backbone componen of vinil ester resin can be derived from on epoxide resin, polyester resin, urethane resin and so on, but those based on epoxide resins are of particular comercial significance.
2. Characteristics
Viny Estwer Resin can be used in e neat from (e.g.., no diluent) or they can countain either a vinyl-type reactive comonomer (e.g.., styrene vinyl toluene, and trimethylol propane tri-acrylate) or a nonreactive diluent (e.g..,methyl ethyl ketone and toluene) Typically, the meth acrylate vinil ester resin contain styrene and are used in chemical-resistand Fibreglass Reinforced Plastic (RFP), whereas the acrylate vinil ester resin are supplied undiluted, with appropriate coreactants added during the formulation of ultraviolet (UV) cure coatings and inks.
3. Electrical Properties
Vinil Ester Resin have not been widely used in electrical applications even though they possess good dielectric strength and resistifity characteristics as shown.
4. Chemical Resistance
At present, the largest commercial use of vinil ester resin (methacrylates) is in chemical resistance FRP equipment: pipe, ducts, scrubbers, flue stacks and storage tanks. They exhibit excellent acid, base and solvent resistance over a wide temperature range in both resin castings and glass laminates. typical chemical resistance data for a vinyl ester resin used in these application.
The excellent acid -base resistance of epoxy-based methacrylate vinyl ester resin is attributable to their low ester content, the protection of the ester linkages by the adjacent methyl shield, and the steric hindrance of the coreactant. ussually atyrene.
5. Shrinkage
Upon Cure, the volumetric shrinkage of vinyl ester resin is generally lower than that of unsaturated polyester resin but higher than that of their parent epoxy resin. The volumetric shrinkage increases with increased backbone double bond and coreactant content. but decreases with increased filler loading or fiber contents.
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