Acrylic-polyester polyols

It is very interesting that acrylic polyols can be used as precursors to synthesise hybrid structures, such as acrylic - polyester polyols, by the polymerisation of some cyclic monomers such as e-caprolactone, initiated by hydroxyl groups of acrylic polyols (reaction 10.2). 

Polyester acrylates are synthesized by esterification of OH groups of polyester polyols with acrylic acid or its derivatives. The typical structure of polyester acrylate oligomers is presented in... 

Uses Polyurethane polyol used in soh/.-based systems modifier for acrylic, polyester, and alkyd resins high-solids coatings, machinery and equip, coatings, appliance coatings, automotive topcoats, paper and wood coatings, aerospace coatings Features Lower VOC... 

Epoxy and polyester polyols, though more expensive than the acrylic polyols, are more chemically and moisture resistant. However, the acrylic polyol, when suitably reacted to form a urethane coating, is satisfactory for weathering atmospheres. 

Products Pigments/dispersions, photoinitiators/sensitizers, acrylate monomers, vinyl ethers, polyols/glycols, epoxy acrylates, polyester acrylates, unsaturated polyesters, urethane acrylates... 

Urethanes are reaction products of isocyanates with materials possessing hydroxyl groups. The polyol side may consist of a number of hydroxyl-containing materials, including water, as well as epoxies, polyesters, acrylics, and drying oils. Epoxy and polyester polyols are more chemically and moisture-resistant than acrylic polyols. They are also more expensive. 

Polyols and polyamines are the most important coreactants for isocyanates. As briefly outlined in Section 4.2.2, the two most common classes of urethane-grade polyols are the polyethers and polyesters. In this section their synthesis and structure are discussed. Other polyol types, such as acrylic resins and polycarbonates, are of more limited applicability and are not presented here. 

Polyols. Typical polyols used in automotive topcoats Include acrylic copolymers and polyesters which have varied number of hydroxyl groups. Acrylic copolymers ranging in number average molecular weight from 1,000 to 10,000 and containing 15-40% by weight of a hydroxy functional comonomer such as hydroxyethyl acrylate have been studied. The acrylic copolymers were prepared by conventional free radical solution polymerization. 

Polyester acrylates are normally formed by the reaction of polyester or polyether polyols reacted with acrylic acid. As with urethane acrylates, this gives the chemical structure of polyester acrylates great... 

Polyester acrylates and urethane acrylates are in common use.307 Cationic systems use vinyl ethers, such as triethyleneglycol divinyl ether, epoxides, and polyols. These... 

Desmophen . (Bayer Miles] Polyester, polyether, or acrylic polyols. 

Fig. 17.6. Epoxidation of soybean oil (a), followed by hydrolysis to form polyols (b). Modification of polyols to form polyesters (c), soybean oil based acrylates (d), and epichlorohydrin modified soybean oil (e).

Prepolymers. A broad range of acrylated resins (oligomers) are commercially available. The film-forming properties depend on the oligomer system. One of the most common is the acrylated epoxy system. In acrylated urethanes, an isocyanate-functional prepolymer with a polyol backbone can be reacted with a hydroxy-functional monomer (e.g., hydroxyethyl or hydroxypropyl acrylate). Many different resins can be synthesized by varying the polyol backbone, the isocyanate type, and the hydroxy-functional monomer. Polyester acrylates are another example of commercially important prepolymers. Acrylated acrylics have an acrylic backbone with pendant acrylate functionality. 

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