Page 168 - Carrahers_Polymer_Chemistry,_Eighth_Edition

Polycondensation Polymers 131

4.13 POLYSULFONES

Polysulfones exhibit excellent thermal oxidative resistance and resistance to hydrolysis and other
industrial solvents and creep. The initial commercial polysulfones were synthesized by the nucleo-
phillic replacement of the chloride on bis(p-chlorophenyl) sulfone by the anhydrous sodium salt of
BPA. It became commercially available in 1966 under the trade name Udel. It exhibits a reasonably
o
high T of 190 C.
g
R O

O
O
(4.82)
S
H C
3
CH 3 O
R
Udel

Union Carbide, in 1976 made available a second-generation polysulfone under the trade name
of Radel. Radel was formed from the reaction of a bisphenol and bis(p-chlorophenyl) sulfone
o
(4.83). This polysulfone exhibites greater chemical/solvent resistance, a greater T of 220 C,
g
greater oxidative stability, and good toughness in comparison to Udel.
O

O
S
(4.83)
R O
O
R
Radel

Polysulfones can also be made from the Friedel–Crafts condensation of sulfonyl chlorides.
Polysulfones are used for ignition components, hair dryers, cookware, and structural foams.
Because of their good hydrolytic stability, good mechanical properties, and high thermal endur-
ance, they are good candidate materials for hot water and food handling equipment, alkaline bat-
tery cases, surgical and laboratory equipment, life support parts, autoclavable trays, tissue culture
bottles, and surgical hollow shapes, and film for hot transparencies. Membranes for use in hemo-

dialysis, gas separation, food and beverage processing, and wastewater recovery have also been

produced from polysulfones. Their low flammability and smoke production, again because of their
tendency for polycyclic formation on thermolysis and presence of moieties that are already partially
oxidized, makes them useful as materials for the aircraft and automotive industries. General prop-
erties of PPS are given in Table 4.11.

4.14 POLY(ETHER ETHER KETONE) AND POLYKETONES
Aromatic polyketones are semicrystalline materials that contain both ketone groups generally

flanked by aromatic units. Many also have included within them ether moieties that allow for some
flexibility and better processing. They have good thermal stabilities, also well as offering good

mechanical properties, flame resistance, impact resistance, and resistance to the environment.

9/14/2010 3:38:34 PM
K10478.indb 131 9/14/2010 3:38:34 PM
K10478.indb 131