|
Showing 1 - 2 of
2 matches in All Departments
Future Directions In Polymer Colloids Hohamed S. EI-Aasser, and
Robert H. Fitch (editors) It is appropriate that the first
NATO-Advanced Research Workshop on "FUTURE DIRECTIONS IN POLYMER
COLLOIDS" was held approximately fifty years after the first
synthetic polymer latexes were made on a commercial scale during
the mid-1930s. Since that time the field of what is now known as
polymer colloids has been evolving rapidly, not only on the
practical level, but also on the scientific and engineering levels.
Billions of pounds of copolymers are manufactured annually by means
of the emulsion polymerization process. "Commodity" polymers as
well "specialty" polymers are prepared today for use in a wide
variety of applications: synthetic rubber, floor coatings, paints,
adhesives, binders for non-woven fabrics, high-impact polymers
latex foam, additives for construction materials such as cement and
concrete, and rheological modifiers. They are also used in numerous
biomedical applications: such as diagnostic tests, immunoassays,
biological cell-labeling, (identi fication and separation), and
drug delivery systems. Small quantities of monodisperse polymer
colloids are used as size calibration standards and find extensive
use as model colloids to test theories in colloids surface and
rheological studies. Advances have been made in our understanding
of the mechanism and kinetics of the emulsion polymerization
process as well as the stability of polymer colloids. Equal
advances were made in engineering areas related to polymer
colloids, e. g. modeling of batch, semi-continuous and continuous
emulsion polymerization and copolymer ization processes."
It is particularly appropriate that this symposium on the emulsion
polymeriza tion of vinyl acetate was held in recognition of the
industrial importance of poly(vinyl acetate) and vinyl acetate
copolymers, and their rather unique properties among emulsion
polymers in general. Poly( vinyl acetate) latexes were the first
synthetic polymer latexes to be made on a commercial scale: their
production using polyvinyl alcohol as emulsifier began in Germany
during the mid-1930s and has continued to the present day, growing
steadily with the years. Indeed, poly(vinyl acetate) latexes
prepared with polyvinyl alcohol are still one of the mainstays of
the adhesives industry. With the passing of time, however, vinyl
acetate copolymers have been developed: copolymers with maleate
esters such as dibutyl maleate, acrylate esters such as ethyl
acrylate and butyl acrylate, versatic acid esters, and, more
recently, ethylene. These versatile copolymers have found
increasing use in more sophisticated adhesives with specialized
properties, adhesives for clay coatings on paper, carpet backing,
and interior and exterior paints. Thus more than 45 years after the
first commercial production of vinyl acetate latexes, their use is
still growing, both in actual quantities and different
applications. The industrial importance of vinyl acetate latexes
makes the mechanism and kinetics of their emulsion polymerization
of practical as well as scientific interest."
|
|