PHTHALIC ACID & Polypropylene Compatibility

Phthalic Acid (C6H4(COOH)2, CAS 88-99-3) is a white crystalline aromatic dicarboxylic acid that is only slightly soluble in cold water. It is more commonly handled as phthalic anhydride. It is an intermediate for phthalate plasticizers used in flexible PVC, alkyd and polyester resins, dyes and pigments. Phthalic acid solutions are mildly acidic and typically stored warm or dilute. Use the compatibility ratings to choose the right tank resin, fittings and gaskets.

PVDF temperature limit: 200°F (95°C). That is Arkema’s maximum use temperature for Kynar Flex® 2850 PVDF, the resin we mold, with Phthalic Acid. Arkema’s limits are for solid resin at atmospheric pressure and do not account for mixtures. Source: Arkema Kynar® PVDF chemical resistance chart. Confirm your application with Bailiff before ordering.

At a glance

Polypropylene is the most economical tank material for Phthalic Acid, rated Excellent. PVDF (Kynar®), HDPE and nylon are also rated Good or better. Avoid Buna-N gaskets.

  • Excellent No or minor effect. Recommended.
  • Good Slight effect. Generally suitable.
  • Fair Moderate effect. Limited or conditional use — contact us.
  • Not Recommended Severe effect. Do not use.
  • No Data Not tested. Contact us before use.

Tank Resins

How Phthalic Acid works with the plastics used to make our storage tanks.

Material Relative cost Rating
HDPE $ Good
Polypropylene $$ Excellent
Nylon $$$ Good
PVDF (Kynar®) $$$$ Excellent

Fittings

How Phthalic Acid works with the plastics used for tank fittings.

Material Rating
HDPE Good
PVC No Data
CPVC Good
Polypropylene Excellent
PVDF Excellent

Gaskets & O-Rings

How Phthalic Acid works with gasket and O-ring materials.

Material Rating
Buna-N Not Recommended
EPDM Excellent
Viton® Excellent

Metals

How Phthalic Acid works with the metals used for fittings and bolts.

Material Rating
316 Stainless Steel Excellent
Hastelloy Good
Titanium No Data
Aluminum Good

Request a Polypropylene Tank Quote

Storing this chemical in polypropylene?

Tanks & Fittings Built for It

Polypropylene tanks from 25 to 6,000 gallons with polypropylene fittings installed. Confirm concentration and temperature with us before you order.

Tell Us What You’re Storing

Send the chemical, concentration, temperature and size. We’ll match the tank and fittings and send a quote.