Synthesis and large scale fractionation of non-linear polymers: brushes and hyperbranched polymers

Hugenberg, Norbert; Loske, St; Müller, Axel H. E.; Schärtl, Wolfgang; Schmidt, Manfred; Simon, Peter F. W.; Strack, A.; Wolf, Bernhard

doi:10.1016/s0022-3093(02)01559-4

Cited by 9 publications

(5 citation statements)

References 6 publications

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“…Free radical homopolymerization of this macromonomer yielded a polystyrene brush with M w = 2.13 × 10 6 g mol −1 and M w / M n = 3.02 (GPC). In order to obtain lower polydispersities, the polystyrene brush was fractionated by continuous polymer fractionation (CPF) . For this study a high molecular mass fraction with M w = 4.12 × 10 6 g mol −1 and M w / M n = 1.51 (weight-average degree of polymerization of the main chain P w = 900) was chosen.…”

Section: Methodsmentioning

confidence: 99%

“…In order to obtain lower polydispersities, the polystyrene brush was fractionated by continuous polymer fractionation (CPF). 60 For this study a high molecular mass fraction with M w ) 4.12 × 10 6 g mol -1 and M w /M n ) 1.51 (weight-average degree of polymerization of the main chain P w ) 900) was chosen. The polystyrene brush was then sulfonated with sulfuric acid/acetic anhydride in 1,2-dichloroethane at 50 °C.…”

Section: Methodsmentioning

confidence: 99%

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Finite-Size Networks from Cylindrical Polyelectrolyte Brushes and Porphyrins

Ruthard

Maskos²,

Kolb³

et al. 2009

Macromolecules

114

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We report on the electrostatic self-assembly of negatively charged cylindrical polystyrenesulfonate (NaPSS) brushes and stiff organic counterions of different valency. In particular, the tetravalent cationic porphyrin meso-tetrakis(4-(trimethylammonium)phenyl)porphyrin (TAPP) yielded two new supramolecular architectures that are stable in aqueous solution. The porphyrin binds to the polyelectrolyte brush due to electrostatic and secondary π-π interactions and can further interconnect the brushes to nanoscale networks. In salt solution individual porphyrin-decorated cylindrical brushes were obtained. Structures formed are characterized by UV-vis spectroscopy, atomic force microscopy (AFM), cryo-transmission electron microscopy (cryo-TEM), small-angle neutron scattering (SANS), and dynamic light scattering (DLS). In order to study porphyrin aggregates by DLS, an IR laser setup (λ ) 831.5 nm) was used. The new morphologies have potential as functional structures in molecular electronics and pharmaceutics.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Finite-Size Networks from Cylindrical Polyelectrolyte Brushes and Porphyrins

Ruthard

Maskos²,

Kolb³

et al. 2009

Macromolecules

114

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“…Brush Polymers. Films of two types of brushes were made (for details of synthesis see ref ): PS-6030 ( M w = 6030 kDa, M w / M n = 1.37) and PS-2930 ( M w = 2930 kDa, M w / M n = 1.28). Both had a PMMA backbone and PS side chains (grafting density 100%).…”

Section: Methodsmentioning

confidence: 99%

Nanowear on Polymer Films of Different Architecture

et al. 2007

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In this paper, we describe atomic force microscope (AFM) friction experiments on different polymers. The aim was to analyze the influence of the physical architecture of the polymer on the degree and mode of wear and on the wear mode. Experiments were carried out with (1) linear polystyrene (PS) and cycloolefinic copolymers of ethylene and norbornene, which are stabilized by entanglements, (2) mechanically stretched PS, (3) polyisoprene-b-polystyrene diblock copolymers, with varying composition, (4) brush polymers consisting of a poly(methyl methacrylate) (PMMA) backbone and PS side chains, (5) PMMA and PS brushes grafted from a silicon wafer, (6) plasma-polymerized PS, and (7) chemically cross-linked polycarbonate. For linear polymers, wear depends critically on the orientation of the chains with respect to the scan direction. With increasing cross-link density, wear was reduced and ripple formation was suppressed. The cross-linking density was the dominating material parameter characterizing wear.

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“…In general, comb‐shaped polymer brushes can be categorized into homopolymer brushes and copolymer brushes. Since the pioneering work reported by Tsukahara et al3, 4 in 1989, extensive investigations have been devoted to the synthesis of homopolymer brushes mainly via three approaches including grafting‐through,5–20 grafting‐from,21–39 and grafting‐onto 40–46. In the past decade, the advent of controlled polymerization techniques, such as ring‐opening polymerization (ROP),5, 24, 25, 30, 37, 43 nitroxide‐mediated polymerization (NMP),47–49 atom transfer radical polymerization (ATRP),16, 31–33, 35, 39 and reversible addition‐fragmentation chain transfer (RAFT) polymerization,50, 51 have rendered the grafting‐from approach more appealing, starting with macroinitiators with the initiating sites distributed on every repeating unit.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of amphiphilic copolymer brushes possessing alternating poly(methyl methacrylate) and poly(N‐isopropylacrylamide) grafts via a combination of ATRP and click chemistry

Yin

Líu

et al. 2009

J. Polym. Sci. A Polym. Chem.

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We report on the synthesis of well‐defined amphiphilic copolymer brushes possessing alternating poly(methyl methacrylate) and poly(N‐isopropylacrylamide) grafts, poly(PMMA‐alt‐PNIPAM), via a combination of atom transfer radical polymerization (ATRP) and click reaction (Scheme ). Firstly, the alternating copolymerization of N‐[2‐(2‐bromoisobutyryloxy)ethyl]maleimide (BIBEMI) with 4‐vinylbenzyl azide (VBA) affords poly(BIBEMI‐alt‐VBA). Bearing bromine and azide moieties arranged in an alternating manner, multifunctional poly(BIBEMI‐alt‐VBA) is capable of initiating ATRP and participating in click reaction. The subsequent ATRP of methyl methacrylate (MMA) using poly(BIBEMI‐alt‐VBA) as the macroinitiator leads to poly(PMMA‐alt‐VBA) copolymer brush. Finally, amphiphilic poly(PMMA‐alt‐PNIPAM) copolymer brush bearing alternating PMMA and PNIPAM grafts is synthesized via the click reaction of poly(PMMA‐alt‐VBA) with an excess of alkynyl‐terminated PNIPAM (alkynyl‐PNIPAM). The click coupling efficiency of PNIPAM grafts is determined to be ∼80%. Differential scanning calorimetry (DSC) analysis of poly(PMMA‐alt‐PNIPAM) reveals two glass transition temperatures (Tg). In aqueous solution, poly(PMMA‐alt‐PNIPAM) supramolecularly self‐assembles into spherical micelles consisting of PMMA cores and thermoresponsive PNIPAM coronas, which were characterized via a combination of temperature‐dependent optical transmittance, micro‐differential scanning calorimetry (micro‐DSC), dynamic and static laser light scattering (LLS), and transmission electron microscopy (TEM). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2608–2619, 2009

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Synthesis and large scale fractionation of non-linear polymers: brushes and hyperbranched polymers

Cited by 9 publications

References 6 publications

Finite-Size Networks from Cylindrical Polyelectrolyte Brushes and Porphyrins

Finite-Size Networks from Cylindrical Polyelectrolyte Brushes and Porphyrins

Nanowear on Polymer Films of Different Architecture

Synthesis of amphiphilic copolymer brushes possessing alternating poly(methyl methacrylate) and poly(N‐isopropylacrylamide) grafts via a combination of ATRP and click chemistry

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