Isobutylvinyl ether

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. 

Brendle described a process which he called polymer grafting, in which particles of molybdenum disulphide or other solid lubricants were coated with various polymers, including polystyrene, polymethylmethacrylate and poly-isobutylvinyl ether. The process was most conveniently carried out by grinding coarse molybdenum disulphide powder in a 20% - 30% solution of the appropriate monomer in a solvent. The quantity of polymer added to the molybdenum disulphide particles was very small, and could not be detected by scanning electron microscopy or infrared spectroscopy. The carbon content (1-4%) indicated a polymer content up to 6% maximum. Brendle considered that the polymer was preferentially grafted onto surface freshly exposed by grinding. This may be partly true, but in view of later... 

Recently, Mengoli and Vidotto restudied these systems and obtained evidence for a direct addition reaction in the initiation of the polymerisation of isobutylvinyl ether by the radical cation perchlorate of 9,10-dijiienylanthracene. The kinetics of styrene polymerisations by the above initiator in nitrdienzene at 10°C were also studied. Important termination reactions giving indanyl-type cations were detected and attrSmt-ed to the perchlorate anion. This system was in fact found to display many similarities with that involving the same monomer and perchloric acid ... 

A wide range of reactions of polar compounds was claimed to be catalysed by zeolites of high Si02/Al203 ratio, such as de-aluminated mordenite and HZSM-5. The liquid-phase dehydration of t-butanol catalysed by H-mordenite was studied by Ignace and Gates.Reaction took place within the pore structure and was hindered by the difficulty of transport of reactant, product, and diluent molecules. Barrer and Oei found that ethylvinyl, n-butylvinyl, and isobutylvinyl ethers all react readily over H-mordenite near room temperature... 

The recent data for kp(+) for A-ethyl-3-vinylcarbazole allows a further interesting correlation of absolute reactivity with structure. The cation derived from this monomer is a substituted p-aminobenzyl type and as such its reactivity might be expected to lie between that of the propagating cation from N-vinylcarbazole and those from isobutylvinyl ether and/7-methoxystyrene. Indeed this seems to be so as the value obtained, 2 x lO s S slots neatly between the figures of 5 x 10 s" and 5 x 10 M s as predicted. 

On the other hand, the Cr-carbene complex reacts with ethylvinyl ether or isobutylvinyl ether, under milder conditions, to give the metathesis product, a-methoxystyreneS ... 

PhPd(OAc)(dppp) is more reactive than PhPdl(dppp) with styrene and methyl acrylate, in agreement with the fact that the dissociation of PhPd(OAc)(dppp) to the reactive PhPd(DMF)(dppp)+ is more effective than that of PhPdl(dppp) (compare the respective values of ki in Table 1.2). Interestingly, an inversion of reactivity is observed with the electron-rich isobutylvinyl ether (Table 1.2). 

According to Scheme 1.35, the major branched product will be formed from an electron-rich alkene in a reaction involving either pure cationic PhPd(DMF)(dppp)+ or neutral PhPdX(dppp) which reacts via the cationic complex, both in the absence of extra anions (I, AcO ) (Scheme 1.35, routea). The linear product will be formed if the reaction is performed in the presence of a large excess of anions (I , AcO ), as it often occurs in real catalytic reactions, but still via the cationic PhPd(DMF)(dppp) (Scheme 1.35, route b ). The inversion of reactivity observed in the reaction of the electron-rich isobutylvinyl ether -PhPdl(dppp) being more reactive than PhPd(OAc)(dppp) (Table 1.2 [53]), although it is less dissociated to the cationic complex - may be understood as the contribution of the... 

Polyisobutylvinyl ether (polyvinyliosbutyl ether) n. Any polymer of isobutylvinyl ether. Some are liquids, others are solid and crystalline. They are used as adhesives, surface coatings, laminating agents, and filling compounds in electrical cables. 

Vinylisobutyl ether (isobutylvinyl ether, IVE) n. H2C=CH0CH2-CH(CH3)2. A colorless, flammable liquid used to make polymers and co-polymers used in coatings. 

The first living cationic polymerization of isobutylvinyl ether was reported with HI/I in 1984 [29]. Sawamoto and coworkers suggested the Hl/vinyl ether adduct acts as an initiator while the acts as an activator [30]. In 1986, complexes of BQ3 with esters, such as cumyl acetate, were reported to initiate the living polymerization of isobutylene [31]. Then, a living cationic polymerization of A-vinylcarbazole with HI in toluene (-40 °C) and methylene chloride (-78 °C) was reported in 1987 [30]. 

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