Preparation of 20-nm poly(styrene derivative) particles via polymerization with nonionic surfactant at the phase-inversion temperature

Poly(styrene derivative) particles, average diameter of which is <30nm, were prepared without ionic emulsifier with nonionic emulsifier polyoxyethylene alkyl phenyl ether by polymerizing monomer, emulsifier, water and initiator mixture at around PIT. Effects of initiator concentration, temperature and monomer type on the average diameter of the generated polymer particles are investigated. Smaller particles are obtained with higher rate of radical generation at PIT. The particles of poly(p-methylstyrene) which have an average diameter of 21 nm and a polymer weight fraction of 5% were prepared.