Polymer formations by radical polymerization of vinyl monomer (M) initiated by an initiator (R-R') are expressed by Eq. (I), if no chain transfer reaction occurs and the termination proceeds via a recombination of the growing radicals.Therefore, radical polymerization may simply be considered as a successive insertion reaction of the monomer molecules into the R-R' bond of the initiator leading to a polymer with two initiator fragments bonded at its both ends. The radical polymerization of styrene initiated by 2,2 '-azoisobutyronitrile is only an example close to such a case'). The above assumptions are, however, generally not realized, and thus the number of initiator fragments per polymer molecule is always less than 2.If the initiator used has a high reactivity for a chain transfer to the initiator, or a part of the radical produced by the initiator easily undergoes primary radical termination, a polymer with two initiator fragments, similar to Eq. (l), can be obtained [Eq. (211. R-R'+nM + R+M+R'(2) Therefore, the choice of such initiators in vinyl polymerization opens the possibility of synthesizing easily monofuntional or a,o-bifunctional oligomers and polymers via radical mechanism, and thus designing a polymer structure by radical polymerization.Thus, we may call such initiators initiator-tranuer agent (inifer), and/or initiatorterminator (initer). Since it is difficult to distinguish between "inifer" and "initer" for usual radical initiators, however, we propose to call them initiator-tranuer agentterminator (iniferter). The concept of "inifer" in cationic polymerization has already been proposed by Kennedy2).When iniferters such as phenylazotriphenylmethane, phenylphenylazosulfide, 1,3diphenyltriazene, alkyl perbenzoates, monosulfides etc., are used in radical polymerization, monofunctional polymers are produced, as shown in Eq.(3), as an example.

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Iron-copper cooperative catalysis is shown to be effective for an alkene-Grignard exchange reaction and alkylmagnesiation of alkynes. The Grignard exchange between terminal alkenes (RCH═CH(2)) and cyclopentylmagnesium bromide was catalyzed by FeCl(3) (2.5 mol %) and CuBr (5 mol %) in combination with PBu(3) (10 mol %) to give RCH(2)CH(2)MgBr in high yields. 1-Alkyl Grignard reagents add to alkynes in the presence of a catalyst system consisting of Fe(acac)(3), CuBr, PBu(3), and N,N,N',N'-tetramethylethylenediamine to give β-alkylvinyl Grignard reagents. The exchange reaction and carbometalation take place on iron, whereas copper assists with the exchange of organic groups between organoiron and organomagnesium species through transmetalation with these species. Sequential reactions consisting of the alkene-Grignard exchange and the alkylmagnesiation of alkynes were successfully conducted by adding an alkyne to a mixture of the first reaction. Isomerization of Grignard reagents from 2-alkyl to 1-alkyl catalyzed by Fe-Cu also is applicable as the first 1-alkyl Grignard formation step.

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ABSTRACT:In contrast to diethyl fumarate (DEF), diethyl maleate (DEM) did not homopolymerize with 2,2'-azobisisobutyronitrile (AIBN), but was found to undergo radical polymerization in the presence of amines such as morpho line (Mor). From the results of radical polymerization of DEF with AIBN and isomerization of DEM with Mor, the radical polymerization of DEM in the presence of both AIBN and Moris considered to proceed via a new monomer-isomerization radical polymerization mechanism, i.e., DEM is isomerized first to DEF which is then homopolymerized. The most efficient isomerization catalyst was Mor among the amines examined. The apparent activation energies for the monomer-isomerization radical polymerization of DEM was calculated to be 91.9 kJmol-1 and that for this isomerization was also obtained as 24.7 kJmol-1 . Moreover, Mor also acted as a retarder of radical polymerization of DEF. The composition relation of the copolymer to the feed monomer mixture in the copolymerizations of DEM with styrene, isobutyl vinyl ether, and acrylonitrile in the presence of Mor was found to be similar to that of the respective copolymerizations of DEF.KEY WORDS Radical Polymerization I Radical Copolymerization Monomer-Isomerization Radical Polymerization I Diethyl Maleate Diethyl Fumarate I It is known that 1,2-disubstituted ethylenic monomers except vinylene carbonate 1 and maleimide derivatives 2 homopolymerize only to a very small extent in the presence of initiator, because of the steric hindrance of the substituents. However, 1,2-disubstituted olefins such as 2-butene, 2-pentene, and 4-phenyl-2-butene were found to polymerize with the Ziegler-Natta catalyst to give high molecular weight homopolymers consisting of the respective !-olefin monomer unit. 3 In these polymerizations, 2-olefins isomerized first to the corresponding 1-olefins which then homopolymerized, and we termed these polymerizations "monomerisomerization polymerization" for which the data obtained from our laboratory have been reported in detail. dialkyl maleates, did not give any homopolymers under similar conditions. 4 -8 However, when amines such as morpholine (Mor) were added to these systems, dialkyl maleates were also found to polymerize. 4 • 6 Recently, various dialkyl fumarates, trans-! ,2-disubstituted monomers, were found to undergo homopolymerization in the presence of a radical initiator to give relatively high molecular weight homopolymers, but the respective cis isomers, i.e., In previous papers, the results of the radical homopolymerization of dimethyl fumarate 7 and dimethyl maleate 8 in either the presence or absence of amines were reported. In order to clarify further the detailed mechanism of the monomerisomerization radical polymerization of dialky'l maleates, the radical polymerization of diethyl maleate (DEM) was undertaken in this study. The results obtained are described in relation to the radical polymerization of diethyl fumarate (DEF). EXPERIMENTAL MaterialsCommercial DEM and DEF were used after fractional distillation under...