Epoxy acrylic graft copolymer

In the case of the epoxy-acrylic graft copolymer, the epoxy is not soluble in the monomer mixture, even as low as a 10% solution. However, the epoxy resin being the majority component acts as the continuous phase. The purpose of the graft epoxy-styrene-methacrylic acid copolymer is to lower the barrier at the interface so that a stable oil-in-oil emulsion is first obtained and upon neutralization with a tertiary amine, dimethyl ethanol amine, a stable oil-in-oil emulsion in water is then obtained. 

From the data generated so far, an attempt was made to determine the epoxy-acrylic graft copolymer composition. 

For the epoxy-acrylic graft copolymer, the apparent degree of grafting is ... 

Synthesis of epoxy-acrylic graft copolymer using free radical means was described. Characterization of the graft copolymer by solvent extraction indicated that the graft copolymer is consisted of the following ... 

The tough and weatherable epoxy-acrylic graft copolymers made by Oriel et al. (20) that were cited earlier were also made from methyl ethyl ketoxime blocked lEM. 

Water-based epoxy resins not applied by electrodeposition are mostly of the anodic type and maleinized epoxy esters are frequently used. Another class is the epoxy acrylic graft copolymer, where the epoxy resin is rendered water-soluble by attaching side chains of acrylic polymer containing a high amount of methacrylic acid. The process of grafting is similar to that of chain transfer (p. 67), where acrylic chains are attached by hydrogen abstraction. This process is illustrated in Fig. 14.2, where C- represents a radical site, and represents an extended acrylic chain containing both methacryclic acid and styrene components. 

A large-scale use of epoxy resins is to make acrylic graft copolymers for interior linings of beverage cans (154). A solution of a BPA epoxy resin in a glycol ether solvent is reacted with ethyl acrylate (2-propenoic acid ethyl ester)... 

The epoxy-acrylic resin referred to above is a graft copolymer prepared by the polymerisation of acrylic monomers in the presence of the epoxy resin in such a way that grafting of the acrylic onto the epoxy takes place. Water dispersibility is achieved by neutralising carboxyl groups in the acrylic polymer chain with ammonia or amine. Amino or phenolic resins are used as crosslinkers. Alternatively, solvent-borne epoxy-amino or epoxy-phenolic lacquers can be used. 

A waterborne system for container coatings was developed based on a graft copolymerization of an advanced epoxy resin and an acrylic (52). The acrylic—vinyl monomers are grafted onto preformed epoxy resins in the presence of a free-radical initiator grafting occurs mainly at the methylene group of the aliphatic backbone on the epoxy resin. The polymeric product is a mixture of methacrylic acid—styrene copolymer, solid epoxy resin, and graft copolymer of the unsaturated monomers onto the epoxy resin backbone. It is dispersible in water upon neutralization with an amine before cure with an amino—formaldehyde resin. 

Other examples of solvent effects in casting blends include epoxy resin/copoly-ester/tetrachloroethane polyethersulphone/poly(ethylene oxide)/cyclohexanone and mixtures of PVC with various polyacrylates in solvents such as THF One particular pair of polymers PVC/poly(ethyl acrylate) appear to be miscible but no suitable solvent has been found as yet. Homogeneous blends can only be prepared by in situ polymerisation though it is possible that miscibility is enhanced by small amounts of graft copolymer which is inevitably formed by this technique. 

Synthesis. lj characterization of the graft copolymer has been reported. The Epoxy resin used is a high molecular weight (Mn=10,000) epichlorohydrin-Bisphenol type, and the acrylic is approximaely a 2 1 molar ratio of methacrylic acld/styrene. The Epoxy/acrylic ratio is approximately 80/20 by weight. Grafting is achieved.by.free radical means... 

Characterization of the graft copolymer by solvent extraction indicates that a substantial amount of the epoxy resin and of the acrylic are free. About 47% of the epoxy resin is ungrafted, 61%... 

Ill) Epoxy functionalities are not essential for grafting. For a graft copolymer made by the reaction of epoxy with carboxyl functionalities, the presence of epoxy functionalities is essential. Since this approach requires carbon-carbon bond formation, ester linkages are not necessary. Therefore epoxy functionalities can be capped with phenol or benzoic acid, etc., or bisphenol-A terminated epoxy resin can be prepared followed by grafting with acid containing monomers, and resultant epoxy-g-acrylic copolymer can be prepared. 

Graft epoxy-acrylic copolymer prepared with a free radical initiator is an example of the "grafting from" process. In the case where benzoyl peroxide was used as the free radical initiator, it is determined that about 77% of the free radical initiator instead of causing initiation of monomers, chain transfers with the epoxy resin backbone, followed by the "grafting from" of22onomers onto the epoxy resin. Benzoyl peroxide is known to decompose mostly (90 ) to the benzoyloxy radical and the (10 ) phenyl radical. Mechanisms of grafting can be demonstrated in the following two schemes. (Schemes A and B). 

An acrylic-alkyd graft copolymer which is water-dispersible was prepared by Walus (30) by copolymerizing methyl methacrylate, butyl methacrylate and methacrylic acid in the presence of an epoxy-modified dehydrated castor oil alkyd which was pre-reacted with lEM. When formulated with NH this gives an air-dry water-dispersible alkyd... 

Z. Yan, W. Uu, N. Gao, H. Wang, K. Su, Synthesis and properties of a novel UV-cured fluorinated siloxane graft copolymer for improved surface, dielectric and tribological properties of epoxy acrylate coating, Appl. Surf. Sci. 284 (2013)683-691. 

PP and POM are both semicrystalline and immiscible, thus at w s 10 wt.% they should be compatibilized and impact modified. Since POM can develop strong hydrogen bonding with acidic or epoxy groups, usually acidified or epoxidized PO has been used. For example, POM blends with PP were compatibilized by addition of muconic acid-grafted PP. Another system comprised POM, thermoplastic urethane (TPU), 10-30 wt.% of either PP, PA, or polyester, and ethylene-butyl acrylate-GMA copolymer, with (EBA-GMA) as compatibilizer. 

Number of grafted copolymers were prepared by the ozonization and grafting technique. Polyolefins, PE and PP, were grafted with fluorinated acrylates to obtain fluorine content between 11% and 25% that highly modified their properties. Likewise, PE and PVDF have been grafted with various acryhc monomers with the aim to improve their adhesive properties. From these products, it has been possible to attach composite materials, based on epoxy resins, to PE or PVDF. The main copolymers prepared according to this technique are summarized in Table 1. 

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