High molecular weight polymers substitution polymerization

In the case of thiophene dioxide, dimerization is preferred to the reaction with a good dienophile such as maleic anhydride and thus the monomer is not suitable for a copolymerization reaction of this type. Certain substituted thiophene dioxides, however, react more readily with good dienophiles and dimerization does not become important in their polymerization reactions (6,16). Thus with a series of 6is-maleimides, 2,5-dimethylthiophene-1,1-dioxide, 3,4-diphenylthiophene-l,l -dioxide and 3,4-dichlorothiophene-l,1-dioxide readily form high molecular weight polymers. 

Polymerization of substituted 1,4-epoxides to high molecular weight polymers is not expected on a thermodynamic basis. Indeed high molecular weight polymers have not yet been prepared. However, 3-MeTHF [106] and 2-MeTHF [96] have both been polymerized to give oligomers. 

Intermolecular hydrosilylation of diethynylsilanes with dihydro-substituted silicon compounds gives high molecular weight polymers -SiR2CH=CH- (e. g., [30]). The polymeric products obtained in the above-mentioned reactions are suitable substrates for ceramic and optoelectronic materials. 

Substituting Eq. (6.199) into Eq. (6.205) and noting that for most addition polymerizations, Rp Rtr + Rt (or high-molecular-weight polymer would not be formed). 

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