Page 20 - Engineering Plastics Handbook

xviii Preface

PPE blended with polystyrene (PS) or high impact PS (HIPS). PPE/
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styrenic blends are commonly referred to as modified PPE. Noryl grades
are blended with other polymers such as polyamide (PA), and in the
twenty-first century, with polypropylene (PP). PPE/PP grades are desig-
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nated Noryl PPX. The author describes the “novel compatibility [of PPE]
with styrenic polymers” and “fortuitous and rather miscible, single-phase
blend,” which is contrasted to alloys based on PPE and PP that are not
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compatible with each other. Noryl PPX grades are made possible by
using General Electric’s patent-pending compatibilization technology,
which takes polyphenylene ether blends and alloys beyond the original
PPE blends with polystyrene resins. “PPE/PP alloys offer product design-
ers materials that fill the gap between the basic properties of high-end
polyolefins and the stronger performance characteristics and attributes
of engineering thermoplastics,” according to the author. The chapter
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provides an abundance of information on Noryl polyphenylene ether
blends and alloys chemistry of polymerization, products, properties, and
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processes, including Noryl ETX used as thermosetting resin property
enhancers.
Chapter 10, “Thermoplastic Polyimide,” from Mitsui Chemicals com-
bines fundamental information with the special attributes of thermo-
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plastic polyamide (TPI) resins, based on Mitsui Chemicals AURUM TPI
grades. The author gets right to the point in the first two paragraphs,
describing the polymeric macromolecular differences between ther-
mosetting polyimides, traditional TPIs, and the company’s in-mold crys-
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tallizable super AURUM TPIs, which were introduced in the early 2000s.
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The author states that “Super AURUM TPI has better chemical and
mechanical properties.” TPI polymerization is “completed through an
optimum of the monomer selection,” according to the author. A descrip-
tion of typical polymerization of thermoplastic polyimide provides a good
illustration of combining polycondensation, ring-opening polyaddition in
solution, and subsequent solid state production of polyimides. The over-
all chemistry of polymerization highlights the nuances relating TPI
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macromolecular characterization to polymer properties. AURUM can
be polymerized without catalysts and it has no post-polymerization resid-
ual solvent, producing “outstanding cleanliness and can be used for semi-
conductor manufacturing equipment parts requiring tighter specs of
cleanliness,” according to the author. TPI high temperature resistance up
to 235°C (455°F ) is a principal reason this engineering thermoplastic is
selected for high temperature semiconductor, wear/friction applications,
automotive transmission, torque converter, and many other components
described in this chapter. The chapter reports on carbon-fiber-reinforced
TPI composites to replace ceramics and metals. Drivetrain components
are at the cutting edge of new engineering thermoplastic automotive
components. The author describes TPI replacing metal for automotive