ISSN:
1435-1536
Keywords:
latex
;
amphoteric
;
ionogenic
;
size
;
polystyrene
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Amphoteric polystyrene latex colloids were prepared by the “emulsifier-free” emulsion polymerization of styrene. Two co-monomers, methacrylic acid (MA) (anionic) and dimethyl aminoethyl methacrylate (DMAM) (cationic) were used to promote the amphoteric nature of the resultant surfaces. Parameters such as particle size and the isoelectric point (IEP) were measured as a function of polymerization recipe. Particle size decreased with increasing initiator concentration according to the equation: log [d w]=−0.67 log [I] + 0.316 whered w is the weight average particle diameter andI is the concentration of initiator (potassium persulphate). The particle size also decreased with increasing temperature, increasing pH and addition of surfactant. Particle size was unaffected by the methacrylic acid content. The isoelectric point pH was decreased on decreasing initiator concentration and on increasing methacrylic acid content. The polymerization pathway was deduced to involve the cationic DMAM during the initiation phase and to involve the anionic MA as well as styrene, during the growth stage. A full polymerization pathway involving the formation of “oligomeric DMAM micelles” was postulated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01411249
