6533b853fe1ef96bd12abfb8
RESEARCH PRODUCT
Branched and Functionalized Polybutadienes by a Facile Two-Step Synthesis
Francisco-j. López-villanuevaFrederik R. WurmHolger Freysubject
Kinetic chain lengthPolymers and PlasticsChemistryOrganic ChemistryChain transferDegree of polymerizationCondensed Matter PhysicsEnd-groupAnionic addition polymerizationPolymerizationPolymer chemistryMaterials ChemistryOrganic chemistryCoordination polymerizationReversible addition−fragmentation chain-transfer polymerizationPhysical and Theoretical Chemistrydescription
Anionic polymerization was used to prepare silane-endfunctionalized polybutadiene macromonomers with different molecular weights ranging from 9 000 to 34000 g .mol- 1 . These were polymerized by a hydrosilylation reaction in bulk to obtain branched polymers, using Karstedt's catalyst. Surprisingly, the addition of monofunctional silanes during the polymerization showed only a minimal effect concerning the degree of polymerization. Furthermore, it was possible to introduce a variety of functional silanes without increasing the overall number of reaction steps by a convenient AB 2 + A type "pseudocopolymerization" method. All branched polymers were analyzed by SEC, SEC-MALLS, SEC-viscosimetry. 1 H NMR spectroscopy, and DSC concerning their branching ratio. The branching parameters for the branched polymers exhibited similar characteristics as for hyperbranched polymers obtained from conventional AB 2 monomers. Detailed kinetic studies showed that the polymerization occurred very rapidly in comparison to the hydrosilylation polymerization of classical AB 2 type carbosilane monomers.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2008-04-04 | Macromolecular Chemistry and Physics |