Controlled Atom Transfer Radical Polymerization Research Articles

Unimolecular Combination of an Atom Transfer Radical Polymerization Initiator and a Lactone Monomer as a Route to New Graft Copolymers

The synthesis, polymerization, and copolymerization of a new cyclic ester, γ-(2-bromo-2-methyl propionyl)-e-caprolactone (3), containing a pendent-activated alkyl bromide functional group is described. This new compound serves as both a monomer for “living” ring-opening polymerization (ROP) as well as an initiator for the controlled atom transfer radical polymerization (ATRP). Three distinctive routes to poly(e-caprolactone)−graft−poly(methyl methacrylate) copolymers were surveyed by either sequential or concurrent living polymerization procedures. The first approach involves the ROP of e-caprolactone with various compositions of 3, followed by the polymerization of methyl methacrylate via ATRP from the activated alkyl bromide sites along the polyester backbone. Alternatively, α-lactone functional methyl methacrylate macromonomers were prepared by ATRP of methyl methacrylate initiated from 3. The macromonomers were copolymerized with e-caprolactone via ROP to form the target graft copolymers. Finally, the...

Synthesis of di- and triblock copolymers of styrene and butyl acrylate by controlled atom transfer radical polymerization

Synthesis of di- and triblock copolymers of styrene and butyl acrylate by controlled atom transfer radical polymerization

Synthesis of di- and triblock copolymers of styrene and butyl acrylate by controlled atom transfer radical polymerization

Di- and triblock copolymers of styrene and butyl acrylate with controlled molar masses (Mn up to ≈ 105) were sequentially prepared by radical atom transfer polymerization in a homogeneous medium using chlorine end capped polymers as initiators and the copper(I) chloride/bipyridine complex as catalyst, in the presence of dimethylformamide. Random poly(styrene-co-butyl acrylate) was synthesized and the cross-over reactions between Cl end capped polystyrene and poly(butyl acrylate) to the opposite monomers were examined.

Transformation of “living” carbocationic and other polymerizations to controlled/“living” radical polymerization

AbstractTransformation of “living” carbocationic polymerization of styrene and isobutene to controlled atom transfer radical polymerization (ATRP) is described and formation of the corresponding AB and ABA block copolymers with styrene (St), methyl methacrylate (MMA, methyl acrylate (MA) and isobornyl acrylate (IBA) was demonstrated. A similar approach was applied to the cationic ring opening polymerization of tetrahydrofuran leading to the AB and ABA block copolymers with St, MMA and MA using ATRP. Site transformation approach was also used for the ring opening metathesis polymerization of norbornene and polycondensation systems using polysulfone as an example. In both cases, AB and ABA block copolymers were efficiently formed with styrene and acrylates.