Synthesis and temperature gradient interaction chromatography of model asymmetric star polymers by the “macromonomer” approach

Abstract

. (2013) 'Synthesis and temperature gradient interaction chromatography of model asymmetric star polymers by the "macromonomer"approach.', European polymer journal., 49 (9). pp. 2769-2784. Further information on publisher's website:http://dx.doi.org/10.1016/j.eurpolymj.2013.06.021Publisher's copyright statement: NOTICE: this is the author's version of a work that was accepted for publication in European Polymer Journal. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be re ected in this document. Changes may have been made to this work since it was submitted for publication. A de nitive version was subsequently published in European Polymer Journal, 49, 9, 2013Journal, 49, 9, , 10.1016Journal, 49, 9, /j.eurpolymj.2013.021. Additional information:Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Abstract. We describe herein the synthesis and characterisation of a series of asymmetric three arm polystyrene stars via the "macromonomer" approach. The stars have been designed as model polymers to probe branched polymer dynamics and in particular to establish the chain-length of side-arm which precipitates a change in the rheological properties of the resulting polymers from "linear-like" to "star-like". Thus, a homologous series of three arm stars have been prepared in which the molar mass of two (long) arms are fixed at 90 000 gmol -1 and the molar mass of the remaining (short) arm is varied from below the entanglement molecular weight (M e ) to above M e . The arms were prepared by living anionic polymerisation, resulting in well-defined chain lengths with narrow molecular weight distribution. In contrast to the usual chlorosilane coupling approach, the macromonomer approach involves the introduction of reactive chain-end functionalities on each of the arms, either through the use of a functionalised (protected) initiator or a functional end-capping agent, which allows the stars to be constructed by a simple condensation coupling reaction. In this study we will compare the relative efficiency of a Williamson and 'click' coupling reaction in producing the stars. Most significantly, although this approach maybe a little more time-consuming than the more common silane coupling reaction, in the present study the "long" arm may be produced in sufficient quantity such that all of the asymmetric stars are produced with long arms of identical molecular weight -the only remaining variable being the molecular weight of th...

Monomer Sequence Control via Living Anionic Copolymerization: Synthesis of Alternating, Statistical, and Telechelic Copolymers and Sequence Analysis by MALDI ToF Mass Spectrometry

“…Telechelic polymers are effectively homopolymers which are functionalized at each and as an end capping monomer for the synthesis of AB 2 macromonomers for the preparation of polystyrene 73 and polybutadiene 74 DendriMacs, polystyrene HyperMacs , 75 and asymmetric stars 76 and polystyrene-polyisoprene-polystyrene HyperBlocks. 72 In none of the above cases was Table 6: DPE-OSi content and molecular weight analysis of P(S-co-DPE-OSi) copolymers.…”

Chain Architecture as an Orthogonal Parameter To Influence Block Copolymer Morphology. Synthesis and Characterization of Hyperbranched Block Copolymers: HyperBlocks

“…Details of the deprotection of the alcohol functionalities and end-group modification reactions to enable both a Williamson coupling reaction and an azide-alkyne 'click' coupling reaction are described in the accompanying electronic supporting information and were carried out as previously reported 54,55,80 . group.…”

“…The polystyrene macromonomers, decorated with reactive end-group functionalities comprising of two phenols (B) and a halide (chloride 48 or bromide 51 ) group (A), undergo a (polycondensation) Williamson coupling reaction to produce the branched HyperMacs. This strategy was subsequently extended to include the synthesis of HyperMacs from poly(methylmethacrylate) and polybutadiene 54 and model asymmetric polystyrene star polymers 55 . Moreover, the macromonomer approach to make LCHB polymers is unique in being able to make hyperbranched block copolymers, HyperBlocks, exemplified in the production of an ABA triblock copolymeric macromonomer of polyisoprene-polystyrene-polyisoprene and first reported by ourselves in a proof of concept study 54 .…”

Dynamics of Star Polymers in Fast Extensional Flow and Stress Relaxation

“…The details of synthesis for Star20 and Star90 can be found in Ref. [20]. Table 1 summarizes the weight average molecular weight M w and the polydispersity index Ð for the two star polymers, where the values are taken from Table 4 in Ref.…”

“…Table 1 summarizes the weight average molecular weight M w and the polydispersity index Ð for the two star polymers, where the values are taken from Table 4 in Ref. [20]. PS lin180 was synthesized by living anionic polymerization under high vacuum conditions by using sec-BuLi as initiator and the reaction was carried out in benzene overnight and terminated with nitrogen-sparged methanol.…”