Synthesis and morphology of model 3-miktoarm star terpolymers of styrene, isoprene and 2-vinyl pyridine

Zioga, Agapi; Sioula, Stella; Hadjichristidis, Nikos

doi:10.1002/1521-3900(200007)157:1<239::aid-masy239>3.0.co;2-i

Cited by 35 publications

(28 citation statements)

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“…Finally, the microstructure observed by Zioga et al [26] exhibited two kinds of hexagonally packed adjoined cylinders (PI and P2VP) in a PS matrix, forming regular curved hexagons, by using preferential stains (either OsO 4 or CH 3 I for the PI or the P2VP phase respectively), where, again, the junction points are confined on parallel and periodically spaced lines which are comprised by the intersection of the three microdomain interfaces.…”

Section: Introductionmentioning

confidence: 91%

Alternating Gyroid Network Structure in an ABC Miktoarm Terpolymer Comprised of Polystyrene and Two Polydienes

et al. 2020

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The synthesis, molecular and morphological characterization of a 3-miktoarm star terpolymer of polystyrene (PS, M¯n = 61.0 kg/mol), polybutadiene (PB, M¯n = 38.2 kg/mol) and polyisoprene (PI, M¯n = 29.2 kg/mol), corresponding to volume fractions (φ) of 0.46, 0.31 and 0.23 respectively, was studied. The major difference of the present material from previous ABC miktoarm stars (which is a star architecture bearing three different segments, all connected to a single junction point) with the same block components is the high 3,4-microstructure (55%) of the PI chains. The interaction parameter and the degree of polymerization of the two polydienes is sufficiently positive to create a three-phase microdomain structure as evidenced by differential scanning calorimetry and transmission electron microscopy (TEM). These results in combination with small-angle X-ray scattering (SAXS) and birefringence experiments suggest a cubic tricontinuous network structure, based on the I4132 space group never reported previously for such an architecture.

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Section: Introductionmentioning

confidence: 91%

Alternating Gyroid Network Structure in an ABC Miktoarm Terpolymer Comprised of Polystyrene and Two Polydienes

et al. 2020

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“…Due to the possible manipulations of chlorosilane cores in developing miktoarm architectures, more methodologies soon followed. While many of these included alterations of polymer addition onto trichlorosilane or tetrachlorosilane cores [ 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 ], one of the more interesting examples was the synthesis of an A 8 B 8 (A = PS, B = PI) miktoarm polymer based on a core with 16 active chlorosilane bonds (called Si-Cl 16 for simplicity). This core was synthesized by transforming a tetravinylsilane initial core with methyldichlorosilane using vinylmagnesium bromide.…”

Section: Synthetic Approaches To Miktoarm Star Polymersmentioning

confidence: 99%

Miktoarm Star Polymers: Branched Architectures in Drug Delivery

Lotocki

Kakkar

2020

Pharmaceutics

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Delivering active pharmaceutical agents to disease sites using soft polymeric nanoparticles continues to be a topical area of research. It is becoming increasingly evident that the composition of amphiphilic macromolecules plays a significant role in developing efficient nanoformulations. Branched architectures with asymmetric polymeric arms emanating from a central core junction have provided a pivotal venue to tailor their key parameters. The build-up of miktoarm stars offers vast polymer arm tunability, aiding in the development of macromolecules with adjustable properties, and allows facile inclusion of endogenous stimulus-responsive entities. Miktoarm star-based micelles have been demonstrated to exhibit denser coronae, very low critical micelle concentrations, high drug loading contents, and sustained drug release profiles. With significant advances in chemical methodologies, synthetic articulation of miktoarm polymer architecture, and determination of their structure-property relationships, are now becoming streamlined. This is helping advance their implementation into formulating efficient therapeutic interventions. This review brings into focus the important discoveries in the syntheses of miktoarm stars of varied compositions, their aqueous self-assembly, and contributions their formulations are making in advancing the field of drug delivery.

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“…In fact, several synthetic examples of 3-arm ABC asymmetric stars by this procedure have been reported so far. 20,24,29,[65][66][67][68][69][70][71] In all of the iterative methodologies herein developed, similar but much more complex intermediate polymer anions are produced as can be seen in Schemes 1-7. Accordingly, one can readily imagine the synthetic procedure using such polymer anions accessible to various asymmetric star-branched polymers.…”

Section: Synthesis Of Asymmetric Star-branched Polymers By Using Intementioning

confidence: 99%

Successive Synthesis of Well-Defined Star-Branched Polymers by Iterative Methodology Based on Living Anionic Polymerization

Hirao

Inoue

Higashihara

et al. 2008

Polym J

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The subject of this review is to introduce a novel iterative methodology based on living anionic polymerization using specially designed 1,1-diphenylethylene (DPE) derivatives recently developed for the synthesis of well-defined many armed star-branched polymers with same or chemically different arm segments. The methodology basically involves only two sets of the following reaction conditions for the entire iterative synthetic sequence: (a) a linking reaction of a living anionic polymer with a DPE-chain-functionalized polymer, and (b) an in situ reaction of a DPE-functionalized agent with the anion generated by the linking reaction to reintroduce the DPE functionality usable for the next reaction. The number of arms to be linked by each stage of the iteration depends on the starting core and DPE-functionalized agents and can dramatically increase by the agent of choice. New functional asymmetric star-branched polymers involving conductive and rigid rod-like poly(acetylene) segment(s) have been synthesized by the methodology using the intermediate polymer anions produced by the linking reaction as macroinitiators to polymerize 4-methylphenyl vinyl sulfoxide, followed by thermal treatment of the resulting star-branched polymers. Star-branched polymers have been widely investigated because of the synthetic challenges associated with preparing them and because they offer unique physical properties quite different from the linear counterparts.1-14 Among star-branched polymers, asymmetric star-branched polymers having chemically different arms have recently attracted much attention because such star polymers should exhibit unique and interesting morphologies as well as properties due to their branched architectures and heterophase structures. As expected, they have exhibited quite different morphological maps from those of linear block copolymers and created novel periodical nano-objects with special shapes that promise potential applications in the field of nanotechnology. Although many star-branched polymers with well-defined structures have been so far synthesized, most of them are composed of less than five arms in regular star-branched polymer and less than three different arms in asymmetric starbranched polymer. The syntheses of regular star-branched polymers with many arms have been achieved only in a few cases even at the present time. With the most established methodology based on the linking reaction of living anionic polymers with multifunctional chlorosilane compounds, welldefined stars could be prepared with maximum arm numbers up to 18. 10,[36][37][38][39] It was also reported that advances in the synthesis of carbosilane dendrimers led to the successful synthesis of poly(1,3-butadiene) stars having 32, 64, and as high as 128 arms. 40,41 Validity of the chlorosilane linking agents throughout the synthesis of star-branched polymers with low molecular weight arms (M n $ 10 3 ) has recently been reevaluated by NMR and MALDI-TOF MS techniques.42,43 For stars having theoretically 32 and 64 arms, the average...

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Synthesis and morphology of model 3-miktoarm star terpolymers of styrene, isoprene and 2-vinyl pyridine

Cited by 35 publications

References 0 publications

Alternating Gyroid Network Structure in an ABC Miktoarm Terpolymer Comprised of Polystyrene and Two Polydienes

Alternating Gyroid Network Structure in an ABC Miktoarm Terpolymer Comprised of Polystyrene and Two Polydienes

Miktoarm Star Polymers: Branched Architectures in Drug Delivery

Successive Synthesis of Well-Defined Star-Branched Polymers by Iterative Methodology Based on Living Anionic Polymerization

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