Environmentally-Friendly Acrylates-Based Polymer Latices - Advanced Materials for Agriculture, Food and Environmental Safety - page 148

tubing, and food cans. Epoxy acrylic systems provide excellent coatings
for appliances, kitchen cabinets, outdoor furniture, aluminum siding,
and other metal products. Waterborne coatings are made by dispersing
or emulsifying the resins with surfactants. Such coatings also have been
based on emulsii ed liquid epoxy resins cured with emulsii ed polyamide
resins. h ese formulations are used in anionic electrodeposited coatings.
h ey provide exterior and interior coatings for underground pipes, and
electrical equipment appliances reinforcement. h e main drawbacks of
epoxy resins for industrial use are their brittleness and high cost.
6.1.4 Acrylics
h e term acrylic resin is generally applied to the polymer and copolymers
of esters of acrylic and methacrylic acids. Acrylics were i rst prepared in
1880 as acrylate by Otto Rohm (1876-1939). He patented it in 1915, and
its suggested use was as a substitute for drying oils in industrial paints and
lacquers. Based on the continuing work in Rohm's laboratory, the i rst lim-
ited production of acrylates began in 1927 by Rohm and Haas Company in
Darmstadt, Germany. h e use of various acrylates could not be explored
for a variety of applications due to their cost till 1950. h e cost of the acry-
lates was reduced by Rohm and Haas in 1950, which resulted in extensive
use of these monomers, particularly in the i eld of coating and printing.
h e polymers based on acrylates contribute to almost 50% of all the poly-
mers used for coating applications. h ese are the most common class of
resins used as binders in surface coatings. Acrylic resins may be used alone
or as blends with other resins to form a suitable binder system for coat-
ings [4]. Paints containing acrylic resins as binders have been known since
1930s. h ey are now one of the largest product classes in the paint and
coating sector. Acrylates and methacrylates are extremely versatile build-
ing blocks used as monomers to synthesize homo- or copolymers.
Acrylics can be formulated as thermoplastic resins, thermosetting resins,
and as a water emulsion latex. h e resins are formed from polymers of acry-
late esters, predominantly polymethyl methacrylate and polyethyl acrylate.
h e acrylate resins do not contain tertiary hydrogens attached directly to the
polymer backbone chain and, as a result, are exceptionally stable to oxygen
and ultraviolet light deterioration. h e repeating units of the acrylic back-
bone are joined to make long polymer chains. A wide range of monomers
is available for use in designing a specii c acrylic system. Typically, mixtures
of monomers are chosen for the properties they impart to the polymer. h e
glass transition temperature of the polymer can be varied by selecting the
proper monomers. h is permits a varied area of application.