Design Guide - Solvay Plastics

Hot Chlorinated Water
Because residual chlorine in water systems combined
with elevated temperatures can produce an oxidizing
environment, resistance to hot water is not always enough.
Since many plastics are susceptible to oxidation and
oxidizing agents, this condition can dramatically shorten
the service life of components made from some plastics.
Typical free chlorine levels in most US municipal water
supplies at the point of use are in the range of 0.5 ppm
to 2 ppm chlorine and are achieved by the addition of
hypochlorites or chloramines.
Several studies have demonstrated that Udel ® polysulfone
based materials offer very good resistance to hot
chlorinated water. Tests were conducted in static water,
containing up to 30 ppm chlorine for 6 months at 60°C
(140°F). As shown in Table 23, Udel ® polysulfone did not
exhibit any significant weight loss.
Tests were also conducted using flowing water containing
5 ppm chlorine for 2 months at 90°C (194°F). As shown
in Table 24, again Udel ® polysulfone did not exhibit any
significant weight loss.
Table 23: Weight Change in Static
Chlorinated Water
Chlorine Content, ppm
Material 0 10 20 30
Udel polysulfone -0.02 -0.02 0.09 0.05
Polyacetal -0.15 -2.96 -4.57 -5.47
CPVC -0.64 -0.56 -0.04 0.08
Weight change after 6 months in water at 60°C (140°F), %
Table 24: Weight Change in Flowing Chlorinated
Water
Chlorine Content, ppm
Steam Sterilization Analysis
Steam autoclaves are widely used to sterilize medical
devices. If polysulfone resin was used for medical
devices, resistance to degradation by steam sterilization
would be a requirement.
To evaluate resistance to steam sterilization, molded
test specimens with dimensions of 127 mm x 13 mm
x 3 mm (5 in. x 0.5 in. x 0.125 in.) were placed in a
steam autoclave. A test cycle consisted of 45 minutes;
30 minutes at a steam pressure of 27 psig (0.18 MPa),
which has a temperature of 132°C (270°F), followed by
15 minutes at atmospheric pressure. The autoclave is
then repressurized to 27 psig (0.18 MPa) for the next
cycle. After the desired number of cycles, the test
specimens were removed from the autoclave, cooled
to room temperature, and after standard conditioning,
tested for tensile strength, Izod impact, and tensile impact
using the appropriate ASTM methods.
The results are shown in Table 25.
Table 25: Property Retention after
Steam Autoclave Exposure
Steam Autoclave Exposure, Cycles
Property 0 50 100
Tensile strength
kpsi 10.8 12.6 12.8
MPa 74 87 88
Notched Izod impact
ft-lb/in. 1.0 0.9 0.8
J/m 53 48 43
Tensile impact
ft-lb/in 2 165 131 116
kJ/m 2 347 276 248
Material 0 5
Udel polysulfone, unfilled 0.0 0.1
Udel polysulfone, 20% glass-filled 0.0 0.0
CPVC -0.6 1.2
Weight change after 2 months in water at 90°C (194°F), %
Property Data
Udel ® Polysulfone Design Guide
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