Methylvinyl ether

Recently, Chaudhari compared the activity of dispersed nanosized metal particles prepared by chemical or radiolytic reduction and stabilized by various polymers (PVP, PVA or poly(methylvinyl ether)) with the one of conventional supported metal catalysts in the partial hydrogenation of 2-butyne-l,4-diol. Several transition metals (e.g., Pd, Pt, Rh, Ru, Ni) were prepared according to conventional methods and subsequently investigated [89]. In general, the catalysts prepared by chemical reduction methods were more active than those prepared by radiolysis, and in all cases aqueous colloids showed a higher catalytic activity (up to 40-fold) in comparison with corresponding conventional catalysts. The best results were obtained with cubic Pd nanosized particles obtained by chemical reduction (Table 9.13). 

Butyl monoester of poly[methylvinyl ether/maleic acid] in isopropyl alcohol (50%) 300.00... 

Addition to F-methylvinyl ether proceeds regioselectively, but only at high temperature producing a mixture of di- and trisulfides in high yield [136] ... 

Using this reaction, we were able to prepare both the mono and disubstituted derivatives, N3P3F,C(OC2H,)=CH2 and N3P3F [C(0C2H3)=CH2]2, without any of the by-product observed in tne case of the propenyl lithium reaction. Similar results were obtained starting with methylvinyl ether. Attempts to achieve trisubstitution led to a complex series of reactions involving... 

Subsequent addition of methyl hypofluorite to 1,2-dichlorofluoroethylene followed by dehalogenation yields methylvinyl ether (MVE), another fluoroalkoxy monomer38 ... 

PFA is a copolymer of TFE and perfluoro(propylvinyl ether) (PPVE) in a mole ratio approximately 100 1. Even such a small amount of comonomer is sufficient to produce a copolymer with a greatly reduced crystallinity. The relatively long side chains also markedly reduce the cold flow. MFA, a copolymer of TFE and perfluoro(methylvinyl ether) (PMVE) has similar properties with a somewhat lower melting point. 

MFA — A copolymer of TFE and perfluoro(methylvinyl ether) with properties similar to PFA. It has about 20°C lower melting temperature than PFA. 

PMVE — Perfluoro(methylvinyl ether) a monomer used for the production of MFA. 

A 1-liter stainless reactor was charged with 450 ml of water, ammonium perfluorononante (3.0 g), disodium phosphate heptahydrate (2.0 g), ammonium persulfate (0.4 g), and vinyl acetate (5.0 g). The reactor was sealed, treated with tetrafluoroethylene (45 g) and perfluoro(methylvinyl ether) (40 g), and heated to 70°C for 8 hours... 

Monomer syntheses and their industrial polymerization and copolymerization were initiated in the thirties by IG Farbenindustrie, now BASF, and this company is still the main producer. Other companies, as GAF Corporation and Union Carbide in the United States or ICI in the United Kingdom came on the market at a later time. Actually BASF is the only producer of homopolymers, whereas copolymers are manufactured by BASF and GAF Co. We shall not consider here the synthesis of the industrial copolymers of methylvinyl ether and maleic anhydride (Gantrez-GAF, Sokalan-BASF), of isobutylvinyl ether and vinyl chloride (Laroflex MP 15-60, BASF), and of isobutylvinyl ether and acrylic monomers (Acro-nal, BASF) as they are produced by radical copolymerization. 

Note FKM, fluorocarbon elastomer VDF, vinylidene fluoride HFP, hexafluoropropyl-ene TFE, tetrafluoroethylene CSM, cure site monomer PMVE, perfluoro-methylvinyl ether. 

Table II Molecular weights of selected commercially available copolymers of poly(methylvinyl ether/maleic anhydride)...

In the solid state, poly(methylvinyl ether/maleic anhydride) copolymers are a white to off-white free flowing, odorless, hygroscopic powders. In solution, poIy(methyIvinyI ether/ maleic anhydride) is a slightly hazy, odorless, viscous liquid. 

Poly(methylvinyl ether/maleic anhydride) copolymers and derivatives are used in denture adhesive bases, controlled-release coatings, enteric coatings, ostomy adhesives, trans-dermal patches, toothpastes, mouthwashes, and trans-dermal gels. Gantrez AN-119 has been used to manufacture... 

Table I Chemical name and CAS registry number for poly(methylvinyl ether/maleic anhydride) copolymers and derivatives.

Poly(methylvinyl ether/maleic anhydride) Gantrez AN-1 19 [9011-16-9]... 

Poly(methylvinyl ether/maleic acid) Gantrez AN-903 Gantrez AN-139 Gantrez AN-149 Gantrez AN-169 Gantrez AN-179 Gantrez S-95 [25153-40-6]... 

Monoethyl ester of poly(methylvinyl ether/maleic acid) (48-52%) in Gantrez S-96 Gantrez S-97 Gantrez ES-225 50% Alcoholic Solution [25087-06-3] [64-17-5]... 

Poly(methylvinyl ether/maleic anhydride) and related free acids are hygroscopic powders and therefore excessive exposure to moisture should be avoided. Aqueous solutions exhibit decreases in viscosity upon exposure to UV light. Polyfmethyl-vinyl ether/maleic anhydride) should be stored in a cool, dry place out of direct sunlight. 

Poly(methylvinyl ether/maleic anhydride) and copolymers are manufactured from methylvinyl ether and maleic anhydride. The 5, ES, and MS grades of Gantrez are manufactured by dispersing AN copolymers in a number of different solvents or salt solutions. ... 

Poly(methylvinyl ether/maleic anhydride) and copolymers are widely used in a diverse range of topical and oral pharmaceutical formulations. These copolymers are generally regarded as nontoxic and nonirritant. Moreover, the dry powders and aqueous solutions are nonirritating with the exception of ES, MS, and A grades, which are irritating to the eye and may cause tissue damage. 

In 1994, Ryu et al. [85] immobilized EFE to polyurethane using maleic anhydride methylvinyl ether copolymer (MAMEC) as an enzyme carrier. The EFE-immobilized polyurethane surface was highly antithrombogenic and had potential for reducing surface induced thrombus. 

MAMEC = Maleic anhydride methylvinyl ether copolymer... 

Other catalysts, used in types of reactions not listed above, vary with the specific reaction involved. A few examples are cited. For the reaction involving the removal of hydrogen from NHa and CH4 to produce HCN, noble-metal catalysts are used. For the synthesis of benzonitrile from toluene and NHs by splitting out hydrogen, molybdenum trioxide is used. 2-Methyl-5-ethylpyridine is produced by reacting methylvinyl ether and NHs at elevated temperatures and pressures over a titanium phosphate or manganese phosphate catalyst supported on calcined silica. ... 

---