Vinyl ester properties

Classification Polymer vinyl ester Properties Wh. beads... 

Thermosetting polyester and vinyl ester properties that contribute to automotive applications include dimensional stability, strength, toughness, and high service temperatures. 

Bisphenol A diglycidyl ether [1675-54-3] reacts readily with methacrylic acid [71-49-4] in the presence of benzyl dimethyl amine catalyst to produce bisphenol epoxy dimethacrylate resins known commercially as vinyl esters. The resins display beneficial tensile properties that provide enhanced stmctural performance, especially in filament-wound glass-reinforced composites. The resins can be modified extensively to alter properties by extending the diepoxide with bisphenol A, phenol novolak, or carboxyl-terrninated mbbers. 

In studies of the polymerization kinetics of triaUyl citrate [6299-73-6] the cyclization constant was found to be intermediate between that of diaUyl succinate and DAP (86). Copolymerization reactivity ratios with vinyl monomers have been reported (87). At 60°C with benzoyl peroxide as initiator, triaUyl citrate retards polymerization of styrene, acrylonitrile, vinyl choloride, and vinyl acetate. Properties of polyfunctional aUyl esters are given in Table 7 some of these esters have sharp odors and cause skin irritation. 

Glycidyl and Vinyl Esters. Glycidyl neodecanoate [26761-45-5] sold commercially as GLYDEXXN-10 (Exxon) or as CarduraElO (Shell), is prepared by the reaction of neodecanoic acid and epichl orohydrin under alkaline conditions, followed by purification. Physical properties of the commercially available material are given in Table 3. The material is a mobile Hquid monomer with a mild odor and is used primarily in coatings. Eor example, it is used as an intermediate for the production of a range of alkyd resins (qv) and acryHcs, and as a reactive diluent for epoxy resins (qv). 

Vinyl ester resins generally offer mechanical properties superior to those of polyester matrices but at an increased cost. Vinyl esters are chemically similar to epoxy resins but are manufactured via a cold-curing process similar to that used in the manufacture of polyester resins. Vinyl esters offer superior resistance to water and chemical attack and are used in such appHcations as underground pipes, tank liners, and storage tanks (see Vinyl polymers). 

Chung [34] concluded that the semiconducting properties of a metal species influence discoloration. In contrast to metals belonging to the insulator group, metals belonging to the semiconductor group promote yellowing, perhaps due to catalysis of the polymerization of vinyl esters. The formation of chromophores is enhanced when the metal has a variable valency with a reduction potential near to zero. 

Sullivan, J.L., Kao, B.G. and van Oene, H. (1984). Shear properties and a stress analysis obtained from vinyl-ester losipescu specimens. Exper. Mech. 24, 223-232. 

These comprise components A to C, the amount of component B being 5 to 50 pbw per 100 pbw of A (based on solid content) and the amount of C being 50 to 350 pbw per 100 pbw of A (based on solid content). A is an emulsion of ethylene-vinyl ester copolymer, which is composed of 5 to 35 wt.% of ethylene and 95 to 65 wt.% of vinyl ester, and has a Tg of -25 to -I-15C and a toluene-insoluble part of 30 wt.% or more. B is a thermal expansive hollow microbead and C is an inorganic filler. The emulsion has superior mechanical strength, crack resistance, water resistance, alkali resistance, blocking resistance, foaming property, embossing property and superior flame resistance and can be used for flameproof foam sheet for wallpaper. 

In the following decades, homo-, co- and terpolymers of VAM with other vinyl esters, (meth)acrylates, and ethylene were developed to give thermoplastic materials with tailored properties that are nowadays produced as solid resins, aqueous dispersions and dispersible powders. 

Copolymers with acrylates (vinyl acrylics) or other vinyl esters are also commonly produced, mostly as aqueous dispersions. They are, independent of the nature of the comonomer, often referred to as copolymers or terpolymers . The presence of comonomers of course heavily influences a number of physical properties like the glass transition temperature and melting point, water solubility or flexibility, to name just a few. 

Apart from the all-carbon backbone, poly(vinyl ester)s also exhibit a unique 1,3-diol structure (see Fig. 1). This structure is a common motif in many natural materials, e.g. carbohydrates. A number of oxidative or reductive electron transfer processes catalysed by natural redox systems are imaginable for this motif. The 1,3-diol structure is unique for a synthetic polymer and cannot be found in any other synthetic polymer class of significance. This explains the unusual biodegradation properties discussed below. 

Vinyl caproate, caprylate, pelargonate, caprate, myristate, pahnitate, stearate, 10-hendecenoate (undecylenate) and oleate can be prepared in a similar manner, except that in the preparation of the pahnitate and stearate the fatty acids are added to a solution of mercuric acetate and sulfuric acid in vinyl acetate. Vinyl stearate is not redistilled, but the once-distilled product is recrystallized from acetone at 0° (3 ml. of acetone per gram of vinyl stearate). The amount of mercuric acetate employed was 2%, and the amount of 100% sulfuric acid was 0.3-0.4%, of the weight of the stearic acid. Average yields and properties of these vinyl esters are given in the table. 

In the same way, ABS acts as a toughener for vinyl ester resins (34). Assessment of the mechanical properties suggest that a chemical reaction may have occurred between the constituents of the blends. The blends are intended as a toughening agent for interlayer toughened vinyl ester/glass composite materials. 

TABLE 1. PROPERTIES OF TYPICAL UNCURED VINYL ESTER RESINS... 

TABLE 2. PROPERTIES OE TYPICAL CURED VINYL ESTER RESLNS... 

The most common advanced composites are made of thermosetting resins, such as epoxy polymers (the most popular singlematrix material), polyesters, vinyl esters, polyurethanes, polyimids, cianamids, bismaleimides, silicones, and melamine. Some of the most widely used thermoplastic polymers are polyvinyl chloride (PVC), PPE (poly[phenylene ether]), polypropylene, PEEK (poly [etheretherketone]), and ABS (acrylonitrile-butadiene-styrene). The precise matrix selected for any given product depends primarily on the physical properties desired for that product. Each type of resin has its own characteristic thermal properties (such as melting point... 

Unsaturated vinyl esters for use in polymerization reactions are made by the esterification of olefins. The most important ones are vinyl esters vinyl acetate, vinyl chloride, acrylonitrile, and vinyl fluoride. The addition reaction may be carried out in either the liquid, vapor, or mixed phases, depending on the properties of the acid. Care must be taken to reduce the polymerization of the vinyl ester produced. 

Epoxy vinyl ester resins are a special class of unsaturated resin. This resin is made by capping an epoxy resin with methacrylic acid and then dissolving in styrene monomer to the desired viscosity. This gives mechanical properties similar to epoxy resins, but the processibility (low viscosity allowing for resin infusion processes) of an unsaturated polyester resin. As with unsaturated vinyl esters, the most common fire retardant vinyl ester resin is based on a resin made from a halogenated system, tetrabromobisphenol A. The level of bromine in the resin and the presence of antimony will determine the fire performance of the resin. These resins are normally used for corrosion resistant equipment or when fire performance and high mechanical properties are required. It is very difficult to get a low smoke value with a brominated vinyl ester resin again due to the fact that bromine... 

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