Macromer Stabilised Polystyrene Latexes

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Macromer Stabilised Polystyrene Latexes

• Paul M. Zelisko
• CHEM 765

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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
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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

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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
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POLY(STYRENE-b-DIMETHYLSILOXANE)

• Advantages
• lowered cost
• straightforward anionic synthesis
• narrow molecular weight distributions
• soluble in many organic solvents

• Disadvantage
• stabilisation by adsorption to polymer

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METHYLMETHACRYLATE-POLY(ETHYLENE OXIDE)

• used in radical dispersion polymerisation of
  styrene
• can get grafting through terminal group
• chemical bond between stabiliser and polymer

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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
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THIOL-ENDED POLY(ETHYLENE OXIDE)

• styrene added to stabiliser under radical
  polymerisation conditions

Colloid Polym Sci, 1997, 275, 716-729
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THIOL-ENDED POLY(ETHYLENE OXIDE)

• maximum 15 of stabiliser grafted to colloid
• remainder in aqeuous phase

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

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POLY(ETHYLENE GLYCOL)-ISOCYANATE
Stabiliser shell
Polystyrene
7 nm
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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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