Azoinitiatoren, 10. Co‐ und terpolymerisation von butadien und styrol mit phenyl(3‐vinylphenylazo)sulfid

Abstract

Phenyl(3-vinylphenylazo) sulfide (2)-displaying not only the properties of an initiator (thermolysis) and a monomer (vinyl group) but also of a chain transfer agent (sulfenyl group) -was copolymerized with styrene in emulsion at 40 "C and in bulk at SO "C. Terpolymerization with styrene and butadiene at 5 "C in emulsion led to azo-containing unsaturated polymers, which could be used for self crosslinking.

Azo Polymers

“…In contrast, linear azo polymers have been obtained via copolymerization of asymmetric azo monomers (25)(26)(27)(28)(29)(30)(31)(32)(33).…”

“…The number of the azo groups in the polymer is controlled by the composition of the monomer mixture and the co-polymerization parameters for the system. An alternative procedure is demonstrated by the telomerization of a styrene, butadiene, azo monomer system (29).…”

“…Molecular weight is determined by osmometry, viscometry, or HPLC (25)(26)(27)(28)(29)(31)(32)(33). Elemental analyses (25)(26)(27)(28)(29), UV spectroscopy (25)(26)(27)29,31,32), derivative UV spectroscopy (35), DSC (36), and 1 H NMR spectroscopy (28,30) are used for determining azo content. The thermal properties of polymers containing side-chain azo groups are similar to those of the low molecular-weight monomers.…”

“…The inclusion of the azo monomers (26) and (27) in a copolymer without decomposition of the azo groups has been achieved via a redox-initiated emulsion copolymerization (25)(26)(27)29,31). Especially interesting in this respect are systems that allow the azo monomer to be incorporated ideally into the polymer, ie, the azo monomer content of the polymer is the same as that of the monomer mixture and independent of the degree of conversion.…”

“…Polymers containing double bonds and side-chain azo groups, eg, (29), can be cross-linked using this technique by slowly heating the polymerization mixture (29). As long as the temperature is kept below the decomposition temperature of the azo groups, the material can be treated as a thermoplastic.…”