Phenolic resin (PF-106) is a resol type thermosetting phenol-formaldehyde polymer used for processing high temperature resistant ablative materials such as carbon phenolic and silica phenolic composites. PF 106 is a high temperature curing resin which has excellent ablative properties and char strength.

The production of PF-106 involves the following steps:

1. Melting of Phenol.

2. Charging of formalin and molten phenol into the reactor in the desired mole ratio.

3. Addition of catalyst.

4. Condensation polymerization of phenol and formalin.

5. Neutralization of reaction mixture with acid.

6. Settling of reaction mixture

7. Removal of water of reaction and salt.

8. Drying of resin to remove traces of water and other volatiles

9. Addition of required quantity of alcohol

10. Filtration and product packing.

11. Storage

Salient Features 
Appearance Yellowish brown to dark brown liquid
Viscosity = 150 - 250
Specific gravity 1.12 – 1.16
Total solid content 60 – 65 for ½ hr. (%)
Free phenol (%) 6 max.
Free formalin (%) 3 max.
Point of trouble 6 – 10 ml of water of resin

Storage conditions 
Temperature 10 - 20°C
Shelf Life 3 months


The resin finds application as binder for high temperature resistant ablative composites materials such as carbon phenolic, silica phenolic and epoxy phenolic systems.


ISRO is willing to offer the knowhow of this technology to suitable entrepreneurs / industries in India. Capable manufacturing industries interested in acquiring this knowhow may write with details of their present activities, requirements and plans for implementation, infrastructure and technical expertise available with them, their own market assessment, if any, and plans for diversification to the address given below:


Technology Transfer & Industrial Coordination Division (TT&IC)

Vikram Sarabhai Space Centre, ISRO PO

Thiruvananthapuram-695 022

E mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Ph: 0471-2564081

Fax: 0471-2564134

Ph: 0471-2564081/2565133/2565695

Fax: 0471-2564134 

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