Page 192 - Manufacturing Engineering and Technology - Kalpakjian, Serope : Schmid, Steven R.

Polymers: Structure,

General Properties,

and Applications

7.I Introduction |7I
° Polymers display a wide range of properties and have several advantages over
7.2 The Structure of
metallic materials, including low cost, good performance, and ease of manufac- Polymers |73
turing; for these reasons, polymers continue to be among the most commonly 7.3 Thermoplastics |80
used materials. 7.4 Thermosetting
Plastics |84
° This chapter first describes the structure of polymers, the polymerization 7.5 Additives in Plastics |84
process, crystallinity, and the glass-transition temperature. 7.6 General Properties
and Applications of
° Mechanical properties and how they are affected by temperature and deforma-
Thermoplastics |85
tion rate are then discussed.
7.7 General Properties
° The chapter describes the two basic types of polymers: thermoplastics and and Applications of
thermosets. Thermosetting
Plastics |88
° Thermoplastics allow a basic manufacturing process of heating them until they 7.8 Biodegradable
soften or melt, and then shaping them into the desired product. Plastics |90
7.9 Elastomers
° The process for thermosets is to form the precursors to a desired shape and
(Rubbers) I9l
then set it through polymerization or cross-linking between polymer chains.
EXAMPLES:
° The chapter also describes the properties and uses of elastomers, or rubbers.
7.I Dental and Medical
° The general properties, typical applications, advantages, and limitations of Bone Cement |77
polymers are discussed throughout the chapter, with several specific examples 7.2 Use of Electrically
given. Conducting Polymers
in Rechargeable
Batteries |83
7.3 Materials for a
1.l Introduction Refrigerator Door
Liner |89

The word plastics first was used as a noun around 1909 and commonly is employed
as a synonym for polymers, a term first used in 1866. Plastics are unique in that they
have extremely large molecules (macromolecules or giant molecules). Consumer and
industrial products made of plastics include food and beverage containers, packag-
ing, signs, housewares, housings for computers and monitors, textiles (clothing),
medical devices, foams, paints, safety shields, toys, appliances, lenses, gears, elec-
tronic and electrical products, and automobile bodies and components.
Because of their many unique and diverse properties, polymers increasingly have
replaced metallic components in applications such as automobiles, civilian and

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