Dilute solution properties of model PMMA-g-PMMA's

Siochi, Emilie J.; DeSimone, Joseph M.; Hellstern, A. M.; McGrath, James E.; Ward, T. C.

doi:10.1021/ma00223a030

Cited by 9 publications

(3 citation statements)

References 14 publications

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“…In addition previous research from different workers reported satisfactory results for similar highly branched, cross-linked copolymer microgel systems using the universal calibration method. 30,31 Further study is required on the thermal diffusion of microgels so that meaningful conclusions can be made regarding these results.…”

Section: Resultsmentioning

confidence: 99%

Determination of Thermal Diffusion Coefficients for Polydisperse Polymers and Microgels by ThFFF and SEC−MALLS

Nguyen¹,

Beckett²,

Pille³

1998

Macromolecules

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A new method combining thermal field-flow fractionation (ThFFF) and SEC−MALLS is proposed for the measurement of the thermal diffusion coefficient D T for polydisperse polymeric samples. This method should greatly increase the range of applicability of ThFFF for characterization of block copolymers and also for studies of thermal diffusion, an interesting phenomenon not yet well understood. ThFFF is one of only a few techniques (e.g., thermal diffusion forced Rayleigh scattering) that can determine D T values of polymers. The values of D T can be used to reflect the surface composition of block copolymer molecules as reported in recent studies. Currently, the value has been measured with ThFFF based on the sample peak maximum method, which can introduce errors when the sample has a broad MW distribution. The method proposed here measures D T by taking all digitized points in the entire sample peak into consideration, and has been tested with polystyrene, poly(tert-butylstyrene), and some copolymer microgels. Preliminary results are presented and discussed.

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Section: Resultsmentioning

confidence: 99%

Determination of Thermal Diffusion Coefficients for Polydisperse Polymers and Microgels by ThFFF and SEC−MALLS

Nguyen¹,

Beckett²,

Pille³

1998

Macromolecules

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“…Strictly speaking, however, the graft copolymers prepared by conventional radical copolymerization with a macromonomer usually have large heterogeneity in the composition due to the difference in the reactivity ratio. For this reason, very limited fundamental studies have been carried out for precise characterization of molecular weight and compositional distribution of the resulting graft copolymers …”

Section: Introductionmentioning

confidence: 99%

“…For this reason, very limited fundamental studies have been carried out for precise characterization of molecular weight and compositional distribution of the resulting graft copolymers. 9 Our interest is focused on establishment of a "designed synthesis" of graft copolymers using the macromonomer technique. If possible, we intend to prepare a model graft copolymer, i.e., that with well-defined branched chain length and sequence as well as narrow molecular weight distribution.…”

Section: Introductionmentioning

confidence: 99%

Micellar Copolymerization of Styrene with Poly(ethylene oxide) Macromonomer in Water: Approach to Unimolecular Nanoparticles via Pseudo-Living Radical Polymerization

2000

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Micellar copolymerizations of amphiphilic ω-methoxy-α-p-styrylalkyl poly(ethylene oxide) (PEO) macromonomers 1 (C1−PEO−C m −S-n, m = 1, 4, 7 and n = 18) with a limited amount of styrene solubilized therein have been investigated. The reactions were carried out with 4,4‘-azobis(4-cyanovaleric acid) (AVA) as a water-soluble initiator and 2,2‘-azobis(isobutyronitrile) (AIBN) as an oil-soluble initiator at 60 °C. Fractional time-evolution experiments revealed that the copolymerization rate of styrene is greatly enhanced by the presence of macromonomer micelles and that the rate increases with hydrophobicity (increase of m) of α-end group of 1. The characterization of the resulting graft copolymers revealed that the organized copolymerization proceeds in the manner of a pseudo-living radical copolymerization with highly limited terminations between compartmentalized (isolated) propagating radicals. That is, the molecular weight of the graft copolymers increased with the conversion of monomers. At an equimolar styrene with 1 (n = 18, m = 7) the copolymerization proceeded apparently transparently and azeotropically to afford a highly branched graft copolymer of poly(styrene-graft-PEO), which in water formed a “unimolecular particle” with 15 nm radius and 7.44 × 106 apparent molecular weight. A plausible mechanism for the present organized copolymerization behavior is presented and discussed.

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Fractionation of Polymers

Barrales‐Rienda

Bello

et al. 1999

The Wiley Database of Polymer Properties

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Dilute solution properties of model PMMA-g-PMMA's

Cited by 9 publications

References 14 publications

Determination of Thermal Diffusion Coefficients for Polydisperse Polymers and Microgels by ThFFF and SEC−MALLS

Determination of Thermal Diffusion Coefficients for Polydisperse Polymers and Microgels by ThFFF and SEC−MALLS

Micellar Copolymerization of Styrene with Poly(ethylene oxide) Macromonomer in Water: Approach to Unimolecular Nanoparticles via Pseudo-Living Radical Polymerization

Fractionation of Polymers

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