ISSN:
1435-1536
Schlagwort(e):
Key words Carboxyl group
;
emulsion polymerization
;
nanoparticles
;
microsphere
;
emulsifier
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
Notizen:
Abstract Styrene-methacrylic acid copolymer (P(S-MAA)) nanoparticles having high Tg were produced by a dissolution of submicron-sized P(S-MAA) particles as follows. Submicron-sized P(S-MAA) particles having various MAA contents were produced by emulsion copolymerization. Secondly, they were treated in a polyoxyethylene nonylphenyl-ether nonionic emulsifier aqueous solution at pH 13.0 and above 90 °C. The nanoparticles having about 30 nm in diameter were only produced from the particles having MAA contents around 7 mol%, and above the contents, they were not produced. It seems to be based on that emulsifier molecules are not adsorbed onto the polymer molecules enough to dissolve them. The effect of MAA content on such a dissolution behavior was examined using seven kinds of different nonionic emulsifiers having hydrophile-lipophile-balance values between 12.2 and 18.2 at various temperatures and initial pH.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/s003960050067
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