Poly(styrene-b-isobutylene-b-styrene) block copolymers produced by living cationic polymerization

Storey, Robson F.; Baugh, Daniel W.; Choate, Kim R.

doi:10.1016/s0032-3861(98)00520-5

Cited by 38 publications

(20 citation statements)

References 4 publications

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“…In Fig. 1 are reported the storage modulus (E 0 ) and the loss tangent (tan d) versus temperature curves of the single PIB network which are characterized by a quite broad a-relaxation composed of a peak centered at À30 C and a shoulder located at À50 C. Those two mechanical relaxation temperatures are associated with the PIB end local rotational chain motion (T a ¼ À50 C) and to the PIB cooperative backbone motion (T a ¼ À30 C) [17e19] and have been observed in other PIB based materials [20,21].…”

Section: Single Networkmentioning

confidence: 79%

“…All IPNs show a complex phase morphology evidenced by two or three distinct mechanical relaxations: the tan d peaks centered at þ134 and À50 C correspond to the mechanical relaxations of rich PCHMA and PIB [20,21] phases. A third relaxation can be detected at þ80 C, a temperature located between those of the mechanical relaxations of PIB and PCHMA.…”

Section: Pib/pchma Ipnsmentioning

confidence: 99%

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Polyisobutene/polycyclohexyl methacrylate interpenetrating polymer networks

Vancaeyzeele

Fichet

Amana

et al. 2006

Polymer

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Section: Single Networkmentioning

confidence: 79%

Section: Pib/pchma Ipnsmentioning

confidence: 99%

Polyisobutene/polycyclohexyl methacrylate interpenetrating polymer networks

Vancaeyzeele

Fichet

Amana

et al. 2006

Polymer

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“…12,20,21 Living cationic polymerization is also applicable to the preparation of block copolymers such as poly(styrene-b-isobutylene-b-styrene). 22 Tang and Liang successfully synthesized Y-shaped block copolymers of poly (ethylene glycol) and poly(N-isopropylacrylamide) (PEG-b-(PNIPAM) 2 ) through the ATRP, 23 and the polystyreneblock-poly(4-vinylpyridine) copolymer by the RAFT. 24 In this paper, we aim to synthesize a series of thermosensitive PNIPAAm-b-PLA block copolymers with various hydrophilic-hydrophobic chain lengths by a novel free racial polymerization process based on a bifunctional initiator, and to examine their micellization and phase transition behavior.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and micellization of thermosensitive PNIPAAm-b-PLA amphiphilic block copolymers based on a bifunctional initiator

Yan

Luo

2011

Macromol. Res.

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The thermo-sensitive amphiphilic block copolymer poly(N-isopropylacrylamide)-block-poly(D,L-lactide) (PNIPAAm-b-PLA) was synthesized using a simple free radical copolymerization route based on a bifunctional initiator, 2,2-azobis(2-methylpropion amidine) dihydrochloride followed by the ring-opening polymerization of D,L-actide in the presence of a Sn(Oct) 2 catalyst. The chemical structure of the PNIPAAm-b-PLA copolymers was verified using Fourier transform-infrared spectrophotometry and nuclear magnetic resonance, and the molecular weight and polydispersity index were examined using gel permeation chromatography. The amphiphilic PNIPAAm-b-PLA block copolymers could self-assemble into spherically shaped micelles in an aqueous solution with a transmission electron microscopy diameter range of 40-56 nm and a dynamic laser scattering hydrodynamic diameter of 90-200 nm. This behavior depends on the environmental temperature, the hydrophobic interactions among PNIPAAm molecular chains, the intermolecular hydrogen bonding between the PNIPAAm chains and water molecules, and the intramolecular hydrogen bonding between the -CONH 2 groups. The copolymers held a critical micellization concentration of 4.93-7.21 mg·L -1 and a low critical solution temperature of 31.15-32.62 o C being more or less affected by their compositions, PLA or PNIPAAm block length, and polymerization temperature. The as-prepared PNIPAAm-b-PLA block polymers are anticipated to be applied as candidate drug release carriers.

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“…As already mentioned at the synthesis of poly(IB-b-St) it is important to add St at~100% IB conversion. The selection of the solvent is also critical, because coupled product that forms in intermolecular alkylation during St polymerization can not be avoided when the solvent is a poor solvent (e.g., Hex/MeCl 60/40 v/v) for PSt [55]. The formation of coupled product is slower in n-BuCl or in MeChx/MeCl 60/40 v/v solvent mixture.…”

Section: Synthesis Using Furan Derivativesmentioning

confidence: 99%

Synthesis of Polyisobutylene-Based Block Copolymers with Precisely Controlled Architecture by Living Cationic Polymerization

Kwon

Faust

2004

New Synthetic Methods

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During the last two decades we have witnessed the discovery and development of living cationic polymerization. As a result of persistent growth in this field, today living cationic polymerization is an equal counterpart of anionic living polymerization although the latter has a considerably longer history. Living cationic polymerization is an indispensable tool for the preparation of a wide variety of homo-, block-, graft-and functional polymers. This chapter reviews recent efforts in cationic macromolecular engineering with emphasis on fundamental concepts and advanced technologies for polyisobutylene block copolymer synthesis. For block copolymer synthesis by the simple sequential monomer addition technique rationalization is given for the selection of polymerization conditions and monomer addition order. The application of non-(homo)polymerizable monomers such as 1,1-diarylethylenes and furan analogues, coupled with changes in the synthetic approaches for various block copolymer architectures, is described in terms of three categories; capping, coupling, and living coupling reactions. These appear to be versatile synthetic tools for numerous linear di-and triblock copolymers, and block copolymers with non-linear architectures. Finally, current developments in the combination of different polymerization mechanisms are illustrated.

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Poly(styrene-b-isobutylene-b-styrene) block copolymers produced by living cationic polymerization

Cited by 38 publications

References 4 publications

Polyisobutene/polycyclohexyl methacrylate interpenetrating polymer networks

Polyisobutene/polycyclohexyl methacrylate interpenetrating polymer networks

Synthesis and micellization of thermosensitive PNIPAAm-b-PLA amphiphilic block copolymers based on a bifunctional initiator

Synthesis of Polyisobutylene-Based Block Copolymers with Precisely Controlled Architecture by Living Cationic Polymerization

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