Poly(acrylate‐b‐styrene‐b‐isobutylene‐b‐styrene‐b‐acrylate) Block Copolymers via Carbocationic and Atom Transfer Radical Polymerizations

Abstract

A series of polyacrylate-polystyrene-polyisobutylene-polystyrene-polyacrylate (X-PS-PIB-PS-X) pentablock terpolymers (X ¼ poly(methyl acrylate) (PMA), poly(butyl acrylate) (PBA), or poly(methyl methacrylate) (PMMA)) was prepared from poly (styrene-b-isobutylene-b-styrene) (PS-PIB-PS) block copolymers (BCPs) using either a Cu(I)Cl/1,1,4,7,7-pentamethyldiethylenetriamine (PMDETA) or Cu(I)Cl/tris[2-(dimethylamino)ethyl]amine (Me 6 TREN) catalyst system. The PS-PIB-PS BCPs were prepared by quasiliving carbocationic polymerization of isobutylene using a difunctional initiator, followed by the sequential addition of styrene, and were used as macroinitiators for the atom transfer radical polymerization (ATRP) of methyl acrylate (MA), n-butyl acrylate (BA), or methyl methacrylate (MMA). The ATRP of MA and BA proceeded in a controlled fashion using either a Cu(I)Cl/PMDETA or Cu(I)Cl/ Me 6 TREN catalyst system, as evidenced by a linear increase in molecular weight with conversion and low PDIs. The polymerization of MMA was less controlled. 1 H-NMR spectroscopy was used to elucidate pentablock copolymer structure and composition. The thermal stabilities of the pentablock copolymers were slightly less than the PS-PIB-PS macroinitiators due to the presence of polyacrylate or polymethacrylate outer block segments. DSC analysis of the pentablock copolymers showed a plurality of glass transition temperatures, indicating a phase separated material.

Structure and Mechanical Properties of an O70 (Fddd) Network-Forming Pentablock Terpolymer

“…Relatively few investigations of symmetric ABCBA pentablock terpolymers have appeared in the literature. ,,– Previous reports have focused on synthetic methodology, – , hydrogel , or ion gel formation, and micellization in solvents. ,,, Only a few reports have interrogated ABCBA pentablock terpolymers in the bulk.…”

“…Heating ISO-7a to 250 °C decreased the segregation strength and increased the chain mobility, enabling the sample to adopt Relatively few investigations of symmetric ABCBA pentablock terpolymers have appeared in the literature. 45,62,[64][65][66][67][68][69][70][71][72][73][74][75][76] Previous reports have focused on synthetic methodology, [64][65][66][67]69 hydrogel 72,76 or ion gel 75 formation, and micellization in solvents. 62,68,70,71 Only a few reports have interrogated ABCBA pentablock terpolymers in the bulk.…”

Allyl Halide (Macro)initiators in ATRP: Synthesis of Block Copolymers with Polyisobutylene Segments

“…Difunctional PIB, capped with several units of styrene, Cl-St- b -PIB- b -St-Cl, prepared cationically was used as an efficient difunctional macroinitiator for homogeneous ATRP. It was extended via ATRP with well-defined segments built from styrene (St), methyl acrylate (MA), methyl methacrylate (MMA), and isobornyl acrylate (IBA). – Recently, Faust et al reported a straightforward synthesis of PIB terminated with an allyl halide group (PIB-allyl-X, where X = Br or Cl) using cationic polymerization. , It was achieved by the addition of 1,3-butadiene (BD) in the presence of Me 1.5 AlBr 1.5 or TiCl 4 co-initiator to living PIB.…”

Kinetic Study of Atom Transfer Radical Copolymerization of Methyl Acrylate and Methyl Methacrylate Initiated with Poly(vinyl acetate) Macroinitiator

“…The recent development of ATRP has opened a new route for the controlled synthesis of several block copolymers (4,5). A wide variety of block copolymers can be derived from the same family of vinyl monomers (6,7) or different families of vinyl monomers via ATRP (8).…”