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[資源]
環(huán)氧乙烯基樹(shù)脂的合成和改性Vinyl ester resin(英文綜述)
Chapter 1. Literature Review
1.1. Introduction
Vinyl ester resins are addition products of various epoxide resins and unsaturated monocarboxylic acids, most commonly methacrylic acid.They have terminal reactive double bonds derived from the carboxylic acid used. These reactive groups can form a crosslinked network with or without the addition of a comonomer. In many industrial products, vinyl ester resins are comprised of 40-50 wt.% styrene. In dental applications triethylene glycol dimethacrylate is the comonomer. It is common to dilute the vinyl ester oligomers with a low molecular weight comonomer, such as styrene, vinyltoluene or methyl methacrylate, to reduce the room temperature viscosity of the mixture and yield a solution with a typical viscosity in the range of 200 to 2000 cps.
Vinyl ester resins combine the best properties of epoxies and unsaturated polyesters. They can be easily handled at room temperature and have mechanical properties similar to epoxy resins. They have better chemical resistance than cheaper polyester resins, especially hydrolytic stability, and at the same time offer greater control over cure rate and reaction conditions than epoxy resins. The unsaturated bonds on the termini of the vinyl ester oligomers copolymerize with the comonomer to form a crosslinked network similar to the curing reactions of unsaturated polyesters. Vinyl ester resins are similar to unsaturated polyester resins in that both systems contain styrene monomer as a reactive diluent and that both unsaturated polyester and vinyl esters provide crosslink sites. However, the physical properties of the vinyl ester networks are, in general, superior to the unsaturated polyesters,particularly corrosion resistance. This can be at least partially attributed to the fact that the vinyl esters have reactive double bonds at the ends of the chains only, while the unsaturated polyester resins have the reactive double bonds distributed throughout the chains. |
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- 附件 1 : Vinyl_ester_Literature_review.pdf
2013-07-19 09:26:40, 136.41 K
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