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Macromer Stabilised Polystyrene Latexes

Macromer Stabilised Polystyrene Latexes. Paul M. Zelisko CHEM 765. initiator. monomer. stabiliser. H 2 O/ ROH. Dispersion Polymerisation. can be used to produce narrow dispersed polymer microparticles latexes used in paints, liquid chromatography, adhesives. polymer.

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Macromer Stabilised Polystyrene Latexes

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  1. Macromer Stabilised Polystyrene Latexes Paul M. Zelisko CHEM 765

  2. initiator monomer stabiliser H2O/ ROH Dispersion Polymerisation • can be used to produce narrow dispersed polymer microparticles • latexes used in paints, liquid chromatography, adhesives polymer Macromolecules.1997, 30, 5673-5682 Colloid Polym Sci. 1997, 275, 716-729 J Polym Sci: Part A: Polym Chem. 1993, 31, 2473 - 2479

  3. Stabilising Colloids • electrostatic stabilisation • steric stabilisation • adsorption • grafting • macromers • polymers with a functionalised terminus for physical adsorption at the interface or for grafting to the polymer colloid

  4. POLY(STYRENE-b-DIMETHYLSILOXANE) • used to stabilise dispersion polymersiation of styrene in CO2 • no chain transfer to silicone, even under radical conditions Macromolecules. 1997, 30, 5673-5682 J Colloid Interface Sci. 1990, 137, 120

  5. Advantages lowered cost straightforward anionic synthesis narrow molecular weight distributions soluble in many organic solvents Disadvantage stabilisation by adsorption to polymer POLY(STYRENE-b-DIMETHYLSILOXANE)

  6. METHYLMETHACRYLATE-POLY(ETHYLENE OXIDE) • used in radical dispersion polymerisation of styrene • can get grafting through terminal group • chemical bond between stabiliser and polymer

  7. METHYLMETHACRYLATE-POLY(ETHYLENE OXIDE) • need PEO chains on macromer that are at least 2000 MW to inhibit flocculation • synthesis of macromer becomes inefficient as PEO reaches limits of effective stability Colloids and Surfaces, 1986, 17, 1-11

  8. THIOL-ENDED POLY(ETHYLENE OXIDE) • styrene added to stabiliser under radical polymerisation conditions Colloid Polym Sci, 1997, 275, 716-729

  9. THIOL-ENDED POLY(ETHYLENE OXIDE) • maximum 15% of stabiliser grafted to colloid • remainder in aqeuous phase

  10. POLY(ETHYLENE GLYCOL)-ISOCYANATE Macromolecules, 2000, 33, 6664-6671

  11. POLY(ETHYLENE GLYCOL)-ISOCYANATE • can be used in radical and ionic polymerisations • 1H-NMR showed that 100% of macromer grafts to the polystyrene • bulky urethane group • hydrolytic stability • monitor reaction using FT-IR

  12. POLY(ETHYLENE GLYCOL)-ISOCYANATE Stabiliser “shell” Polystyrene ~7 nm

  13. Conclusions • develop a macromer to suit experimental goals • ideal macromer can react in ionic and/or radical polymerisation • macromers are an effective means of stabilising colloids

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