Untitled
| dc.rights.license | open | |
| hal.structure.identifier | Laboratoire de Chimie des polymères organiques [LCPO] | |
| dc.contributor.author | FENG, Xiaoshuang | |
| hal.structure.identifier | Laboratoire de Chimie des polymères organiques [LCPO] | |
| hal.structure.identifier | Team 1 LCPO : Polymerization Catalyses & Engineering | |
| dc.contributor.author | TATON, Daniel | |
| hal.structure.identifier | Laboratoire de Chimie des polymères organiques [LCPO] | |
| dc.contributor.author | BORSALI, Redouane | |
| hal.structure.identifier | Lab Biomol Mat Res [LBMR] | |
| dc.contributor.author | CHAIKOF, Elliot L. | |
| hal.structure.identifier | Laboratoire de Chimie des polymères organiques [LCPO] | |
| dc.contributor.author | GNANOU, Yves | |
| dc.date.accessioned | 2020 | |
| dc.date.available | 2020 | |
| dc.date.issued | 2006 | |
| dc.identifier.issn | 0002-7863 | |
| dc.identifier.uri | https://oskar-bordeaux.fr/handle/20.500.12278/20727 | |
| dc.description.abstractEn | Poly(ethylene oxide) (PEO) and poly(acrylic acid) (PAA), two polymers known to form pH-sensitive aggregates through noncovalent interactions, were assembled in purposely designed architecture sa dendrimer-like PEO scaffold carrying short inner PAA chains-to produce unimolecular systems that exhibit pH responsiveness. Because of the particular placement of the PAA chains within the dendrimer-like structure, intermolecular complexation between acrylic acid (AA) and ethylene oxide (EO) units-and thus macroscopic aggregation or even mesoscopic micellization-could be avoided in favor of the sole intramolecular complexation. The sensitivity of such interactions to pH was exploited to generate dendrimer-like PEOs that reversibly shrink and expand with the pH. Such PAA-carrying dendrimer-like PEOs were synthesized in two main steps. First, a fifth-generation dendrimer-like PEO was obtained by combining anionic ring-opening polymerization (AROP) of ethylene oxide from a tris-hydroxylated core and selective branching reactions of PEO chain ends. To this end, an AB(2)C-type branching agent was designed: the latter includes a chloromethyl (A) group for its covalent attachment to the arm ends, two geminal hydroxyls (B-2) protected in the form of a ketal ring for the growth of subsequent PEO generations by AROP, and a vinylic (C) double bonds for further functionalization of the interior of dendrimer-like PEOs. Reiteration of AROP and derivatization of PEO branches allowed us to prepare a dendrimer-like PEO of fourth generation with a total molar mass of 52,000 g center dot mol(-1), containing 24 external hydroxyl functions and 21 inner vinylic groups in the interior. A fifth generation of PEO chains was generated from this parent dendrimer-like PEO of fourth generation using a "conventional" AB(2)-type branching agent, and 48 PEO branches could be grown by AROP. The 48 outer hydroxy-end groups of the fifth-generation dendrimer-like PEO obtained were subsequently quantitatively converted into inert benzylic groups using benzyl bromide. The 21 internal vinylic groups carried by the PEO scaffold were then chemically modified in a two-step sequence into bromoester groups. The latter which are atom transfer radical polymerization (ATRP) initiating sites thus served to grow poly(tert-butylacrylate) chains. After a final step of hydrolysis of the tert-butyl ester groups, double, hydrophilic, dendrimer-like PEOs comprising 21 internal junction-attached poly(acrylic acid) (PAA) blocks could be obtained. Dynamic light scattering was used to determine the size of these dendrimer-like species in water and to investigate their response to pH variation: in particular, how the pH-sensitive complexation of EO and AA units affects their overall behavior. | |
| dc.language.iso | en | |
| dc.publisher | American Chemical Society | |
| dc.subject.en | POLYSTYRENE | |
| dc.subject.en | COPOLYMERS | |
| dc.subject.en | CORED DENDRIMERS | |
| dc.subject.en | LIVING RADICAL POLYMERIZATION | |
| dc.subject.en | TERMINATOR MULTIFUNCTIONAL INITIATOR | |
| dc.subject.en | STAR POLYMERS | |
| dc.subject.en | CONVENTIONAL MONOMERS | |
| dc.subject.en | SURFACE-PROPERTIES | |
| dc.subject.en | CHEMISTRY | |
| dc.subject.en | MACROMOLECULES | |
| dc.type | Article de revue | |
| dc.identifier.doi | 10.1021/ja0631605 | |
| dc.subject.hal | Chimie/Polymères | |
| bordeaux.journal | Journal of the American Chemical Society | |
| bordeaux.page | 11551-11562 | |
| bordeaux.volume | 128 | |
| bordeaux.hal.laboratories | Laboratoire de Chimie des Polymères Organiques (LCPO) - UMR 5629 | * |
| bordeaux.issue | 35 | |
| bordeaux.institution | Bordeaux INP | |
| bordeaux.institution | Université de Bordeaux | |
| bordeaux.peerReviewed | oui | |
| hal.identifier | hal-00368852 | |
| hal.version | 1 | |
| hal.origin.link | https://hal.archives-ouvertes.fr//hal-00368852v1 | |
| bordeaux.COinS | ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Journal%20of%20the%20American%20Chemical%20Society&rft.date=2006&rft.volume=128&rft.issue=35&rft.spage=11551-11562&rft.epage=11551-11562&rft.eissn=0002-7863&rft.issn=0002-7863&rft.au=FENG,%20Xiaoshuang&TATON,%20Daniel&BORSALI,%20Redouane&CHAIKOF,%20Elliot%20L.&GNANOU,%20Yves&rft.genre=article |
Files in this item
| Files | Size | Format | View |
|---|---|---|---|
|
There are no files associated with this item. |
|||