Dispersion polymerizations in supercritical carbon dioxide.
Science
; 265(5170): 356-9, 1994 Jul 15.
Article
en En
| MEDLINE
| ID: mdl-17838034
ABSTRACT
Conventional heterogeneous dispersion polymerizations of unsaturated monomers are performed in either aqueous or organic dispersing media with the addition of interfacially active agents to stabilize the colloidal dispersion that forms. Successful stabilization of the polymer colloid during polymerization results in the formation of high molar mass polymers with high rates of polymerization. An environmentally responsible alternative to aqueous and organic dispersing media for heterogeneous dispersion polymerizations is described in which supercritical carbon dioxide (CO(2)) is used in conjunction with molecularly engineered free radical initiators and amphipathic molecules that are specifically designed to be interfacially active in CO(2). Conventional lipophilic monomers, exemplified by methyl methacrylate, can be quantitatively (>90 percent) polymerized heterogeneously to very high degrees of polymerization (>3000) in supercritical CO(2) in the presence of an added stabilizer to form kinetically stable dispersions that result in micrometer-sized particles with a narrow size distribution.
Buscar en Google
Colección:
01-internacional
Banco de datos:
MEDLINE
Idioma:
En
Revista:
Science
Año:
1994
Tipo del documento:
Article