Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 15 July 1994:
Vol. 265. no. 5170, pp. 356 - 359
DOI: 10.1126/science.265.5170.356
Prev | Table of Contents | Next

Articles

Dispersion Polymerizations in Supercritical Carbon Dioxide

J. M. DeSimone 1, E. E. Maury 1, Y. Z. Menceloglu 1, J. B. McClain 1, T. J. Romack 1, and J. R. Combes 1

1 Department of Chemistry, University of North Carolina at Chapel Hill, CB 3290, Venable and Kenan Laboratories, Chapel Hill, NC 27599, USA.

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 (CO2) is used in conjunction with molecularly engineered free radical initiators and amphipathic molecules that are specifically designed to be interfacially active in CO2. Conventional lipophilic monomers, exemplified by methyl methacrylate, can be quantitatively (>90 percent) polymerized heterogeneously to very high degrees of polymerization (>3000) in supercritical CO2 in the presence of an added stabilizer to form kinetically stable dispersions that result in micrometer-sized particles with a narrow size distribution.

Submitted on March 29, 1994
Accepted on May 18, 1994


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Advances in Carbon Dioxide Based Sizing and Desizing.
L. E. Bowman, N. H. Reade, R. T. Hallen, and A. Butenhoff (1998)
Textile Research Journal 68, 732-738
   Abstract »    PDF »
Sizing and Desizing Polyester / Cotton Blend Yarns Using Liquid Carbon Dioxide.
L. E. Bowman, C. G. Caley, R. T. Hallen, and J. L. Fulton (1996)
Textile Research Journal 66, 795-802
   Abstract »    PDF »
Homogeneous Catalysis in Supercritical Fluids.
P. G. Jessop, T. Ikariya, and R. Noyori (1995)
Science 269, 1065-1069
   Abstract »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)