Branched polymers
AssigneeThe University of Liverpool
InventorsSteve Rannard, Pierre Chambon, Savannah Cassin
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Abstract
A method of preparing a branched polymer comprises the free radical polymerisation of a multivinyl monomer in the presence of a chain transfer agent, using a source of radicals, wherein the extent of propagation is controlled relative to the extent of chain transfer to prevent gelation of the polymer. The average length of each vinyl polymer chain within the product is short.
Claims15
A method of preparing a branched polymer comprising the free radical chain-growth polymerisation of one or more multivinyl monomers, and optionally one or more monovinyl monomers, in the presence of one or more chain transfer agents, using a source of radicals;
- wherein at least 1 molar equivalent of chain transfer agent is used relative to molar equivalent of said one or more multivinyl monomers;
- provided that when one or more multivinyl monomers plus one or more monovinyl monomers are incorporated, then 50 mol % or more of the vinyl monomers used are multivinyl monomers;
- wherein the conversion, during said free radical polymerisation, of double bond functionality to saturated carbon-carbon bonds in the polymer is 80% or more;
- wherein a branched architecture of the branched polymer is formed by propagating more than one vinyl group of at least one multivinyl monomer molecule of said one or more multivinyl monomers into separate vinyl polymer chain segments;
- and
- wherein the one or more chain transfer agents is selected from a thiol, alpha-methylstyrene dimer, 2-isopropoxyethanol, and any combination thereof.
A method of preparing a branched polymer comprising the free radical chain-growth polymerisation of one or more multivinyl monomers, and optionally one or more monovinyl monomers, in the presence of one or more chain transfer agents, using a source of radicals;
- provided that when one or more multivinyl monomers plus one or more monovinyl monomers are incorporated, then 50 mol % or more of the vinyl monomers used are multivinyl monomers;
- wherein the conversion, during said free radical polymerisation, of double bond functionality to saturated carbon-carbon bonds in the polymer is 80% or more;
- wherein propagation is controlled relative to chain transfer to achieve a polymer having a multiplicity of vinyl polymer chain segments wherein the average vinyl polymer chain segment contains between 1 and 3 multivinyl monomer residues;
- wherein a branched architecture of the branched polymer is formed by propagating more than one vinyl group of at least one multivinyl monomer molecule of said one or more multivinyl monomers into separate vinyl polymer chain segments;
- and
- wherein the one or more chain transfer agents is selected from a thiol, alpha-methylstyrene dimer, 2-isopropoxyethanol, and any combination thereof.
Dependencies are inferred from the claim text.