INUMESCENT TECHNOLOGY FOR THERMOSET RESINS

1. INUMESCENT TECHNOLOGY FOR THERMOSET RESINS PHILIP S. RHODES BROADVIEW TECHNOLOGIES NOV. 14-15, 2005

2. INTUMESCENT TECHNOLGY • Provides fire protection by building a continuous char foam layer on the polymer surface when exposed to heat or flame.

3. Different types of fire retardants • Halogenated additives and resins • Water releasing additives • Intumescing agents/ char formers • Activated intumescing agents

4. PROS Cost effective Efficient at low loading levels CONS Harmful thermal decomposition products Dioxins produced when burned in resource recovery plants Halogenated additives and resins

5. PROS Low cost CONS High loading levels Only provides short term protection Water releasing additives

6. PROS Non hazardous thermal decomposition products Long term fire and thermal protection CONS High loading levels Only work with select resins May require synergists Intumescent agents

7. PROS Long term thermal protection Low-moderate loading levels Work with a wide variety of resins CONS Moderately expensive Still require the right resin-intumescent agent match Activated intumescent agents

8. Intumescent agents How do they work?

9. Intumescent agents are catalysts for char formation • They convert to mineral acids when heated but are non acidic at temperatures below 200 C • Catalyze dehydration reactions • Work best with organic compounds that can undergo dehydration reactions

10. Classic dehydration reaction R-OH + R’OH + ACID = R-O-R’ + HOH = R-O-R + HOH =R’-O-R’ + HOH

11. What types of compounds readily undergo dehydration reactions • Starches • Sugars • Cellulosics • Pentaerythritol

12. Starch (C6 H10 O5)n Pentaerythritol C5 H10 O4

13. Can intumescent agents work if the carbons do not contain a oxygen/nitrogen functional group? The answer is YES.

14. Two approaches to overcome a low number of functional groups • The addition of additives that contain a high number of functional groups such as pentaerythritol and melamine • Use of an activated intumescent agent

15. What is an activated intumescent agent? An intumescent agent that will help add functional groups onto hydrocarbons when they do not exist.

16. When polymers start thermal decomposition what happens? • Hydrogens are stripped off forming carbon-carbon double bonds • The hydrogen combines with oxygen in the vapor phase to produce water vapor and heat • The carbon bonds break and low molecular weight alkenes enter the vapor phase • These alkenes are further split and oxidized to produce CO, COO and HOH

17. What happens in the presence of an activated intumescent • Hydrogens are stripped off forming carbon-carbon double bonds • The hydrogen combines with oxygen in the vapor phase to produce water vapor and heat • The water vapor adds back across the double bonds via a catalytic route • The hydroxyls formed combine to form thermally stable ether linkages that produce char • During this dehydration reaction water is released cooling the polymer via a ablative mechanism

18. Formulation DER 331 10 ANC. 350A 4.5 INTU. AC2BG 1.5 PROPERTIES (5 mil coating) Char yield 66% Char ht(mil) 1000 Expansion 200 x Protection 40 m Epoxy example

19. Formulation Poly diol 61 TMP 2.5 Int AC2hph 36.5 MDI 22.5 Properties (5 mil coating) Char yield 62% Char ht 250 Expansion 50x Protection 29 m Urethane example

20. Formulation RH TR (50%s) 10 Intu AC3WM 3 Properties (5 mil dry coating) Char yield 76% Char ht 450 Expansion 90x Protection 36 m Styrene acrylic

21. Formulation Polpropylene 10 Plasticizer 1 Intu AC-3 3 Properties (5 mil film on steel) Char yield 70% Char ht 60 Expansion 12x Protection 18 m Polypropylene