Maleic anhydride, copolymerization with vinyl

The latter technique is more rapid than the former (27, 31). In 1930 Wagner-Jauregg showed that alternating copolymers are obtained when maleic anhydride is copolymerized with vinyl monomers (34). This is true for copolymerization in good solvents, but when the molar ratio of styrene to maleic anhydride is greater than 1, styrene may add to the alternating copolymer in poor solvents to produce block copolymers. 

Hydrophobic regions can be one or two small, well-defined blocks of pendant hydrophobic moieties in an otherwise water-soluble polymer (2-4). An example is a water-soluble sulfonated BAB triblock copolymer where B is hydrophobic f-butylstyrene and A is vinyltoluene (2). However, hydro-phobic regions can also be less well-defined as well as more numerous in a polymer molecule than is the case for a triblock copolymer (5-22). For example, pendant alkyl esters appear to have been randomly incorporated in styrene-maleic anhydride (5) and vinyl benzyl ether-styrene-maleic anhydride (6-ii) copolymers. Also, alkyl polyoxyethylene acrylate monomers can be copolymerized with acrylamide to yield copolymers with pendant hydrophobic chains (12-15). More recently it was found (16-22) that small amounts of water-insoluble monomers that are solubilized by surfactants into aqueous solutions of a hydrophilic monomer produce copolymers with pendant hydrophobic chains, but the size, number, and nature of the hydro-phobic regions has not been determined. 

Reaction of maleic anhydride with thioalcohols and hydroxythioether to give thioesters which are copolymerized with vinyl monomers [26]. 

The nature and the amount of solvent can influence the yield and the composition of the copolymers in these copolymerizations. Copolymerization of phenanthrene with maleic anhydride in benzene yields a 1 2 adduct. In dioxane, however, a 1 1 adduct is obtained. In dimethyl formamide no copolymer forms at all. Another example is a terpolymerization of acrylonitrile with 2-chloroethyl vinyl ether and maleic anhydride or with p-diaxene-maleic anhydride. The amount of acrylonitrile in the teipolymer increases with an increase in the r-electron density of the solvent in the following order ... 

A very common copolymer of vinyl chloride is with vinyl acetate. Copolymerization with vinyl acetate improves stability and molding characteristics. The copolymers are also used as fibers and as coatings. Copolymers intended for use in moldings are usually prepared by suspension polymerization. Those intended for coating purposes are prepared by solution, emulsion, and suspension polymerizations. The copolymers used in molding typically contain about 10% poly(vinyl acetate). Copolymers that are prepared for coating purposes can contain from 10-17% poly(vinyl acetate). For coatings, a third comonomer may be included in some resins. This third component may, for instance, be maleic anhydride, in small quantities, like 1%, to improve adhesion to surfaces. 

The copolymers obtained by radical copolymerization of maleic anhydride (MA) with acrylic or vinyl comonomers, and the maleic add copolymers, generally obtained by the hydrolysis of the maleic anhydride copolymers (Figure 10.1), can be called maleic copolymers. They were intensively studied from a theoretical perspective, but also for their applications [1-3]. Copolymers ofMA with electron-donating comonomers, such as styrene, vinyl acetate, N-vinyl pyrrolidone, and methyl vinyl ether, have an alternant structure [ 1 ], but when MA is copolymerized with electron-acceptor comonomers like methyl methacrylate, acrylonitrile, statistic copolymers are obtained [1,2]. MA units from the copolymers are very reactive active agents with amine or hydroxyl groups... 

Free-radical copolymerization of alkyl vinyl ethers has been carried out with the following typical monomers acrylic acid (bulk and emulsion) [39,40], acrylonitrile (emulsion) [26,27], acrylic esters (emulsion) [41], methyl methacrylate (bulk) [42], maleic anhydride (solution) [43], vinyl acetate (bulk and emulsion) [27,44,45], and vinyl chloride (emulsion) [26, 37,46]. The properties of these and other copolymers are described in a technical bulletin by General Aniline Film Corporation [38]. 

Maleic anhydride is used in a multitude of appHcations in which a vinyl copolymer is produced by the copolymerization of maleic anhydride with other molecules having a vinyl functionaHty. Typical copolymers and their end uses are Hsted in Table 11. 

Vinyl resins ie, copolymers of vinyl chloride and vinyl acetate which contain hydroxyl groups from the partial hydrolysis of vinyl acetate and/or carboxyl groups, eg, from copolymerized maleic anhydride, may be formulated with alkyd resins to improve their appHcation properties and adhesion. The blends are primarily used in making marine top-coat paints. 

VEs can also copolymerize by free-radical initiation with a variety of comonomers. According to the and rvalues of 0.023 and —1.77 (isobutyl vinyl ether), VEs are expected to form ideal copolymers with monomers of similar and e values or alternating copolymers with monomers such as maleic anhydride (MAN) that have high values of opposite sign (Q = 0.23 e = 2.25). 

A variety of trichloroethylene copolymers have been reported, none with apparent commercial significance. The alternating copolymer with vinyl acetate has been patented as an adhesive (11) and as a flame retardant (12,13). Copolymerization with 1,3-butadiene and its homologues has been reported (14—16). Other comonomers include acrylonitrile (17), isobutyl vinyl ether (18), maleic anhydride (19), and styrene (20). 

The largest single use of maleic anhydride is in the preparation of unsaturated polyester resins. It is first esterihed with a polyalcohol (two or more hydroxyls) and then the double bond is copolymerized (crosslinked) with a vinyl monomer such as styrene to form a rigid structure. Such resins are usually reinforced with hberglass (FRP). Maleic anhydride is also used to make oil additives and agricultural chemicals. 

Hydroxyl containing polymers may be cross-linked with diisocyanates. Fordyce and Ferry cross-linked styrene-maleic anhydride copolymers through the action of glycols. The copolymerization of divinyl with vinyl monomers may be looked upon as a method of cross-linking chain polymers. The cross-linkages are introduced simultaneously with the growth of the linear polymer chains, rather than afterwards, but this difference is secondary. 

Trialkylstannyl methacrylates (TASM) readily undergo free-radical copolymerization with maleic anhydride 2,19), styrene871, and vinyl chloride24,88>. 

Difunctional vinvl ether/difunctional N-maleimide. Up until this point, our results have centered on the reactivity of monofunctional maleimide divinyl ether mixtures. From Kloosterboer s26 work for acrylate polymerization, it is known that the rate of polymerization of a free-radical process is increased dramatically as the functionality of the acrylate is increased. In order to enhance the polymerization rates of maleimide divinyl ether systems, it was decided to synthesize difimctional maleimides for copolymerization with difunctional vinyl ethers. The results in Table V indicate that the photoinitiated TTDBM [bismaleimide made from maleic anhydride and 4,7,10-... 

A range of reactions of 2-chlorocyclohexyl(dichloro)phosphine (60) with alcohols and epoxides has been described, largely with a view to the synthesis of polymer intermediates and flame-retardants.50 The copolymerization of dichloro(phenyl)-phosphine with styrene and vinyl butyl ether in the presence of maleic anhydride has been studied.61... 

The high electron richness of vinylferrocene as a monomer is illustrated in its copolymerization with maleic anhydride, where 1 1 alternation copolymers are formed over a wide range of monomer feed ratios and ri -2 = 0.003. Subsequently, a large number of detailed copolymerization studies have been undertaken using metal-containing vinyl monomers. 

The polymerization of alkyl vinyl ethers is of some commercial importance. The homopolymers, which can be obtained only by cationic polymerization, are useful as plasticizers of other polymers, adhesives, and coatings. (The copolymerization of vinyl ethers with acrylates, vinyl acetate, maleic anhydride, and other monomers is achieved by radical polymerization but not the homopolymerizations of alkyl vinyl ethers.)... 

It was found that a mixture of 4-vinylpyridine with p-chlorostyrene copolymerizes without any initiator in the presence of poly(maleic anhydride) at 50°C in DMF. The fact that poly(maleic anhydride) cannot initiate the polymerization of styrene or phenyl vinyl ether shows that poly(maleic anhydride) does not act as a normal anionic or cationic initiator. The compositions of copolymers obtained with various initial compositions of... 

Another important use of BC13 is as a Friedel-Crafts catalyst in various polymerization, alkylation, and acylation reactions, and in other organic syntheses (see Friedel-Crafts reaction). Examples include conversion of cydophosphazenes to polymers (81,82) polymerization of olefins such as ethylene (75,83—88) graft polymerization of vinyl chloride and isobutylene (89) stereospecific polymerization of propylene (90) copolymerization of isobutylene and styrene (91,92), and other unsaturated aromatics with maleic anhydride (93) polymerization of norbomene (94), butadiene (95) preparation of electrically conducting epoxy resins (96), and polymers containing B and N (97) and selective demethylation of methoxy groups ortho to OH groups (98). 

The processing properties of poly(vinyl chloride) has been improved by copolymerizing vinyl chloride with a small amount of vinyl alkyl ether. Copolymers of vinyl alkyl ethers and maleic anhydride arc used as water soluble thickeners, paper additives, textile assistants and in cleaning formulations. 

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