Most water-based solutions of acids, bases, or neutral salts have no different effect on Ryton® PPS compounds than water alone. The primary exceptions are strong oxidizing acids, such as nitric acid, hydrochloric acid, or peroxy acids (see Oxidizing Chemicals). Relatively non-oxidizing acids, such as sulfuric acid and phosphoric acid, have little effect on PPS except under very severe conditions such as high concentration and temperature. Strong bases, such as concentrated sodium hydroxide or potassium hydroxide solutions, do not degrade PPS (the polymer is actually synthesized in a highly caustic environment at high temperature). Acids and bases tend to enhance and accelerate hydrolytic attack of polymer-reinforcement interfaces (see Hot Water), but the ultimate reduction in performance is typically not much worse than what occurs in water alone. Ryton® PPS is compatible with any non-oxidizing organic acids subject to the same cautions that apply to organic chemicals in general. See the Organic Chemicals section for a discussion of the effects of organic bases (amines) and aromatic or halogenated organic chemicals. We generally do not recommend use of compounds containing mineral fillers in service with strong acids (pH < 2) because of the susceptibility of some mineral fillers to acid digestion. Hydrofluoric acid will rapidly attack glass fiber reinforcements.
Effects of Strong Acids and Strong Bases on Ryton® R-4
Chemical Exposure Conditions
Tensile Strength Retained
Weight Change
Transverse Swell
37% Hydrochloric Acid
24 hours, 200°F (93°C)
61%
+ 1.5 %
3 months, 200°F (93°C)
35%
- 10.2 %
12 months, 200°F (93°C)
27%
- 0.7 %
10% Nitric Acid
24 hours, 200°F (93°C)
91%
0.0 %
3 months, 200°F (93°C)
0%
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85% Phosphoric Acid
24 hours, 200°F (93°C)
100%
0.0 %
3 months, 200°F (93°C)
99%
- 0.3 %
12 months, 200°F (93°C)
89%
- 7.2 %
30% Sulfuric Acid
24 hours, 200°F (93°C)
94%
+ 1.3 %
3 months, 200°F (93°C)
89%
+ 1.3 %
12 months, 200°F (93°C)
61%
+ 3.1 %
50% Sulfuric Acid
1 week, 200°F (93°C)
80%
+ 1.8 %
16 weeks, 200°F (93°C)
69%
+ 0.8 %
52 weeks, 200°F (93°C)
73%
+ 1.6 %
80% Sulfuric Acid
1 week, 200°F (93°C)
85%
+ 1.5 %
16 weeks, 200°F (93°C)
85%
+ 0.6 %
52 weeks, 200°F (93°C)
46%
+ 2.1 %
30% Sodium Hydroxide
24 hours, 200°F (93°C)
100%
+ 0.1 %
3 months, 200°F (93°C)
89%
+ 10.5%
12 months, 200°F (93°C)
63%
+ 13.0 %
Effects of 50% Aqueous Zinc Chloride on Ryton® PPS Compounds
