Page 18 - Engineering Plastics Handbook

xvi Preface

polycondensation (step growth) polymerization and addition (chain
growth) polymerization; and the many additional methods such as inter-
facial, solution, free radical, bulk (mass), solid state, emulsion, suspen-
sion, and ring opening. Chapter 2, “Products and Design,” connects the
four introductory chapters with the statement, “Design opportunities
begin with properties introduced by the chemistry of polymerization, and
they continue through fabrication processes and assembly technologies.”
The author provides a basis for understanding the unique combination
of the elastic and viscous behavior of engineering thermoplastics by pre-
senting a logical sequence of spring-and-dashpot models. The models
begin with the simple Hookean spring element and Newtonian dashpot
element, concluding with the more complex multielement models. The
chapter presents a perspective for shear viscosity and shear modulus,
Poisson’s ratio, the Boltzmann superposition principal, the Williams-
Landel-Ferry (WLF) time-temperature superposition, master curve and
shift factor, dynamic mechanical analysis (DMA), and design for assem-
bly (DFA).
Chapter 3, “Properties,” identifies and lists American Society for Testing
and Materials (ASTM International) and many International Organization
for Standardization (ISO) standard test methods and specifications for
engineering thermoplastics covered in the Handbook. Properties covered
in Chap. 3 include details on dynamic mechanical properties, applied
torque, shear, creep, and clear engineering plastics properties. Chapter
4, “Processing,” provides background for complex and critical decisions
such as injection molding machine flight designs and other screw designs.
Processing considerations provide readers with useful insight into pro-
cessing engineering thermoplastics.
Chapter 5, “Polyacetals,” written by the Editor, describes similarities
and differences between acetal homopolymers and copolymers, and the
increasing replacement of metals by both polyacetals. Special attention is
given to formaldehyde chemistry and its important functions in the poly-
merization of polyacetals. New polyacetal compounds narrow the gap
between acetal homopolymers and copolymers such as thermal properties
and toughness. New compounds are increasing the uses of decorated poly-
acetal resins for coated, painted, and metallized products. Selected processes
in the chapter cover rotational molding, foam molding, overmolding, ther-
moforming, and powder metal injection molding (MIM).
Chapter 6, “Acrylonitrile-Butadiene-Styrene Resin,” from LG Chem,
describes subjects of particular current importance, including flame retar-
dant, transparent, heat resistant, and weatherable grades, especially
ABS alloys such as ABS/PC, ABS/PVC, ABS/PA, and ABS/poly(methyl
methacrylate). Flame-retardant compounds are used for components in
electrical and electronic products, housings for computer monitors, print-
ers, and copiers. The chapter provides special attention to environmental