Abstract: Shape, size and composition are nature's most fundamental design features, enabling highly complex functionalities. Despite recent advances, the independent control of shape, size and chemistry of macromolecules remains a synthetic challenge. Herein reported is a scalable methodology to produce large well-defined macromolecules with programmable shape, size and chemistry that combines reactor engineering principles and controlled polymerizations. Specifically, bottlebrush polymers with conical, ellipsoidal and concave architectures are synthesized using two orthogonal polymerizations. The chemical versatility is highlighted by the synthesis of a compositional asymmetric cone. The strong agreement between predictions and experiments validate the precision that this methodology offers.

Abstract: Shape, size and composition are nature's most fundamental design features, enabling highly complex functionalities. Despite recent advances, the independent control of shape, size and chemistry of macromolecules remains a synthetic challenge. Herein reported is a scalable methodology to produce large well-defined macromolecules with programmable shape, size and chemistry that combines reactor engineering principles and controlled polymerizations. Specifically, bottlebrush polymers with conical, ellipsoidal and concave architectures are synthesized using two orthogonal polymerizations. The chemical versatility is highlighted by the synthesis of a compositional asymmetric cone. The strong agreement between predictions and experiments validate the precision that this methodology offers.

Abstract: A strategy for the synthesis of semi-telechelic polyethylene through the palladium diimine-catalyzed chain transfer polymerization of ethylene using various silanes as chain transfer agents is reported. Polymer molecular weight and end-group chemical structure can be tuned by varying the chain transfer agent as well as its concentration. NMR spectroscopy confirms that the silicon of the chain transfer agent is incorporated into the polymer. The stability of the catalyst toward polar monomer enables the chain transfer polymerization of semi-telechelic poly(ethylene-methyl acrylate) copolymers.

Abstract: A methodology is described for the synthesis of polyolefin containing block-copolymers using a catalytic postpolymerization modification strategy. Common polyolefin grades may be converted into macroinitiators using a cross-metathesis reaction. The functionalized polyolefins may then be used to initiate living: coordinative ring opening polymerization of cyclic ester monomer, anionic ring opening polymerization of epoxide monomer, and radical polymerization of vinylic monomer, to yield the corresponding block copolymers.

Abstract: A methodology is described for the synthesis of polyolefin containing block-copolymers using a catalytic postpolymerization modification strategy. Common polyolefin grades may be converted into macroinitiators using a cross-metathesis reaction. The functionalized polyolefins may then be used to initiate living: coordinative ring opening polymerization of cyclic ester monomer, anionic ring opening polymerization of epoxide monomer, and radical polymerization of vinylic monomer, to yield the corresponding block copolymers.

Abstract: A strategy for the synthesis of semi-telechelic polyethylene through the palladium diimine-catalyzed chain transfer polymerization of ethylene using various silanes as chain transfer agents is reported. Polymer molecular weight and end-group chemical structure can be tuned by varying the chain transfer agent as well as its concentration. NMR spectroscopy confirms that the silicon of the chain transfer agent is incorporated into the polymer. The stability of the catalyst toward polar monomer enables the chain transfer polymerization of semi-telechelic poly(ethylene-methyl acrylate) copolymers.