Building Design and Construction Handbook - Merritt - Ventech!

4.86 SECTION FOUR
in resisting oxidizing acid salts like chromates and nitrates but is not resistant to
ferric, cupric, or mercuric chlorides. It resists scaling and oxidation in air and
furnace atmospheres at temperatures up to 2000�F.
4.67 NICKEL BIBLIOGRAPHY
International Nickel Co., New York: ‘‘Nickel and Nickel Alloys.’’
Albert Hoerson, Jr.: ‘‘Nonferrous-clad Plate Steels,’’ Chap. 13 in A. G. H. Dietz,
‘‘Composite Engineering Laminates,’’ M.I.T. Press, Cambridge, Mass.
PLASTICS
The synonymous terms plastics and synthetic resins denote synthetic organic high
polymers, all of which are plastic at some stage in their manufacture. Plastics fall
into two large categories—thermoplastic and thermosetting materials.
4.68 GENERAL PROPERTIES OF PLASTICS
Thermoplastics may be softened by heating and hardened by cooling any number
of times. Thermosetting materials are either originally soft or liquid, or they soften
once upon heating; but upon further
heating, they harden permanently. Some
thermosetting materials harden by an interlinking
mechanism in which water or
other by-product is given off, by a process
called condensation; but others,
like the unsaturated polyesters, harden
by a direct interlinking of the basic molecules
without release of a by-product.
Most plastics are modified with plasticizers,
fillers, or other ingredients.
FIGURE 4.5 Stress-strain diagram shows the
influence of temperature, plasticizer, and rate of
loading on behavior of plastics.
Consequently, each base material forms
the nucleus for a large number of products
having a wide variety of properties.
This section can only indicate generally
the range of properties to be expected.
Because plastics are quite different in
their composition and structure from
other materials, such as metals, their behavior
under stress and under other conditions
is likely to be different from
other materials. Just as steel and lead are
markedly different and are used for different
applications, so the various plastics
materials—some hard and brittle, others soft and extensible—must be designed