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        # Titanium Dioxide (TiO2) in PVC: Rutile vs. Anatase Grade Performance

        

**Topic:** Explainer

        

In hot, sunny climates across India, Asia, and Africa, rigid PVC products suffer intense UV exposure. Titanium dioxide ($TiO_2$) is a critical UV stabilizer. Using silica-alumina treated rutile grades like [NBT Titanium Dioxide (Rutile Grade)](/products/additives/tio2-rutile) protects profiles from photolytic chalking and yellowing.

        
        
        
        
        
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          ## Frequently Asked Questions

          
### Why does anatase TiO2 cause PVC to chalk?

Anatase TiO2 has high photocatalytic activity. Under UV radiation, it generates hydroxyl radicals that attack and degrade the surrounding polymer matrix, exposing the pigment particles as a loose white powder.

### How does silica coating improve weatherability?

A silica coating forms a physical barrier around the TiO2 crystal, trapping photochemically generated radicals and preventing them from reacting with the host PVC polymer.

### Can I use TiO2 to reduce formulation cost?

No. TiO2 is a functional white pigment and UV stabilizer, not a filler. To optimize cost, blend TiO2 with fine-particle calcium carbonate filler while maintaining the minimum TiO2 required for UV protection.

### What is the CAS number for Titanium Dioxide?

The CAS registry number for Titanium Dioxide is 13463-67-7.

        
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By NBT Technical Desk · Updated 2026-07-04

        

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