Polymer foam is a large and diverse
industry that touches almost every
aspect of daily life. The material finds
use in numerous items, from hot-drink
cups and food containers to running
shoes, furniture, automotive seating, and
window frames. Few materials are as
versatile or as widely used.
Compiling a text on as wide-ranging
a topic as this is challenging, but
Dr. Daniel Klempner and Dr. Vahid Sendijarevic have co-authored a book
that is comprehensive, up-to-date,
and readable. The 584-page Polymeric
Foams and Foam Technology is the
second edition of this title, which
Klempner, affiliated with the University
of Detroit Mercy, and Sendijarevic, of
Troy Polymers Inc., originally published
a decade ago. The new edition covers
the basics of process technology, looks
at the latest developments in chemistry,
and includes advances in critical
regulatory areas like blowing agents,
combustibility, and solid-waste disposal.
Written with input from 20 contributors,
the book is primarily for scientists,
engineers, and academics, yet is also
useful for product marketers who must
keep current with developments in foam
technology.
The first three chapters present the
basics of flexible, semi-flexible, and rigid
polymer foams. The authors discuss
foam densities; mechanical, physical,
and chemical means of creating foam
structures; process techniques for
fabricating foam parts and products like
slabstock; key industries and markets;
and regulatory challenges on fronting
the industry.
There are, of course, two basic
categories of polymer foam:
thermoplastic and thermoset. While the
book is almost exclusively concerned
with plastic foams, there is discussion
of rubber materials, including chapters
dedicated to latex and silicone foams.
This provides readers with additional
perspective on the industry and
increases the value of the text.
Klempner and Sendijarevic include
graphs, equations, tables, and diagrams
throughout the book to illustrate key
points. These are detailed enough for
scientists and engineers, yet can be
understood by readers who don’t have a
technical background.
Specific types of foam are covered
in separate chapters beginning with
chapter 4. These include: flexible and
rigid polyurethane; polyisocyanurate;
polystyrene; polyolefin; polyvinyl
chloride; epoxy; latex; silicone;
fluoropolymer; wood-flour composite;
phenolic; and syntactic polymer
(i.e., polymer with filler of hollow
microspheres). While there are other
types of polymer foams, these materials
account for most applications. The
format of each chapter varies, but basic
information includes an introduction to
the material, its structure and chemistry,
details on foam formation and properties,
applications, and a list of references for
further study.
Of special note is inclusion of woodflour
composite (WFC) foams. WFC is
a small but rapidly growing segment
of the market that offers advantages
to fabricators. WFC is less expensive
than most foam fillers; reduces wear
and tear on process machinery versus
conventional fillers and fibers; can have
better properties than conventional
fillers and fibers; and is a durable, lowmaintenance
replacement for wood in
some applications. The chapter on WFC
foam, written by Chul B. Park of the
University of Toronto, is an informative
look at a relatively new foam technology.
The remaining chapters cover flame
retardance and blowing agents.
Contributor Roza M. Aseeva of the
Institute of Biochemical Physics in
Moscow, begins the chapter on flame
retardants by noting that most fires
worldwide occur in buildings and
transportation where polymer products
are concentrated. Decreasing the fire
hazard of polymeric materials, including
foams, is an important aspect of fire
safety. Aseeva discusses a number of
subjects relevant to the combustibility of polymer foams, and concludes with
a look at recent advances in flame
retardance. These include the use of
polymers that are inherently flame
retardant, fire-resistant coatings, and
new additives like polymer/ceramic
hybrid nanocomposites.
The chapter on blowing agents, by
Fyodor A. Shutov and Donald P. Visco
Jr., both of Tennessee Technological
University, discusses the chemistry and
properties of physical and chemical
blowing agents. Shutov and Visco add
perspective by examining the regulatory
issues affecting blowing agents, and
reviewing alternative materials with zero
ozone-depletion potential. They make the
point that while some alternative blowing
agents are more evironmentally friendly
than conventional blowing agents, many
carry tradeoffs, and ultimately, scientists
and engineers need to look at the entire
properties’ spectrum of a blowing agent,
including its insulation effectiveness, in
determining its environmental impact.
The book concludes with appendices
of Greek and Roman letters used in
scientific notations and a listing of
conversion factors used in describing
foam properties. These appendices
are useful, but brief. The authors might
consider expanding them if a future
edition is planned, and including a list of
foam trade names and major chemical
and product suppliers to the industry.
Klempner and Sendijarevic have
done a masterly job of developing an
authoritative and readable text on a
material that is an essential component
of product performance. Polymeric
Foams and Foam Technology remains
a classic reference on an important
segment of plastics fabrication.
