Page 693 - Carrahers_Polymer_Chemistry,_Eighth_Edition

656 Carraher’s Polymer Chemistry

more intimately mixed, because of the sameness of the PP that is both the discontinuous and continu-
ous phases, allowing more efficient transfer of impact energies. Also, because it is one single material,

it is easy to recycle lending to it being a more environmentally friendly material. It is being used in
automotive applications, including at the race track. Because of its outstanding impact resistance, it
is used as the race car splitter and to reinforce other parts of the race cars. If it does fail, unlike other
composite materials that often shatter leaving unwanted debris on the track, Trgris materials retain
their entirety. Further, because of the layering, fractures do not propagate throughout the entire Trgris
part. Other uses are in transportation as liners and floors; in water sports in the construction of small

boats and watercraft; in construction of blast resistance materials; and it is being used in the construc-
tion of playground and outdoor objects.
A second material recently introduced as Impaxx is an energy absorbing foam developed by
Dow Automotive. It reduces weight, space, cost, and improves safety. It is composed of foamed PS
so is similar to disposable coffee cups. Impaxx is a closed foam material. On impact, the closed
foam cells compress and buckle absorbing energy and when excessive impact energy is applied the
cells rupture again absorbing energy. Impaxx is used in more than 2 million automobiles, includ-
ing the Honda Pilot, Chevy Malibu, and Ford Crown Victoria as well as a number of racing cars. It
is used as headliners and pillar trims, steering column and lower instrument panels, under carpet,
front and rear doors, and in bumper systems. Again, it is advertised as being green friendly since it
is all PS and can be readily and easily recycled.
CarbonX is made by Chapman Thermal Products and is in competition with Nomex and similar

materials as a flame-resistant material. CarbonX is made by a controlled heating of polyacryloni-
trile forming a fully oxidized fused polycyclic composition similar to that described in Chapter 10.
The material can be heated to 500, 1,000°C or higher giving a material that is then stable to that
temperature since material that is unstable has already been driven off. The oxidized polyacrylo-
nitrile (OPAN) is forced through small holes resulting in the formation of tiny fi ber-like materials,

which are not particularly flexible. Thus, the OPAN is often woven with other fibers, including steel

fibers, giving the material additional strength and fl exibility.

Even if some burning occurs, the OPAN fabric expands removing oxygen. CarbonX materials
are replacing some of the fabrics previously made by Nomex. Nomex and CarbonX garments are
made for use by fi re fighters, steel mill workers, military, race track drivers and other personal, and

police and include undergarments, socks, suits, head gear, shoelaces, and escape blankets. CarbonX
comes in your choice of colors as long as you want black. Other colors are achieved through blend-

ing colored fibers in with the CarbonX fi bers.
Safety glass is also undergoing changes. Along with the poly(vinyl butrylate) (PVB) innerlayers,
other materials are being used, including PET, EVA, and ionoplast as innerlayers. DuPont, Solutia,
and PPG have pioneered in lots of these efforts so that the applications are not just for the automo-
tive windshields but for many architectural uses. The U-shaped Grand Canyon Skywalk that extends
70 feet from the rim and 4,000 feet above the Colorado river employs laminated glass. The balus-
trades have laminated bent glass of two 3/8 in. layers with a 0.06 in. PVB interlayer. The 2-in. thick
glass floor has five layers of glass alternating with four layers of SentryGlas Plus. The SentryGlas

Plus has an ionoplast resin composition that is five times stronger and with 100-fold rigidity com-
pared with the traditional PVB innerlayers. The walkway can support more than 70 million pounds;
can withstand sustained winds in excess of 100 miles h; and an 8.0 magnitude earthquake.
Head-up displays (HUDs) allow drivers to view important information as Global Positioning
Systems (GPSs) on the windshield. These systems use laminated glass combinations as Wedge,
which is a Butacite PVB interlayer that converts the windshield into a transparent liquid crystal dis-
play. Wedge is also employed as outer windows for large-scale buildings with the ability to color the
glass in an assortment of colors and hues.
Layered glass also contributes to savings of heat and our health. Tempered glass absorbs about
60 UV radiation, while laminated glass blocks more than 90% of the UV radiation equivalent to a
sun protection factor (SPF) of 50.

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