Sage Journals: Discover world-class research

Abstract

Liquid hydrocarbons and hydrofluorocarbons (HFCs) are the leading zero ozone depletion potential (ODP) blowing agents being considered for rigid polyurethane foam insulation used in the construction industry. Different isomers of pentane, namely normal-, iso- and cyclopentane, are the major hydrocarbons under consideration. The leading HFCs being evaluated are HFC-245fa (CF3-CH0-CF9H) and HFC-365mfc (CF3-CH2-CF2-CH3).

The solubility of such blowing agents in many of the typical polyols and isocyanates used by the construction industry is limited. Additives have been used to improve the solubility of blowing agents in the past. For example, ethoxylated nonylphenol was added to many polyols in order to enhance CFC-11 (CCI3F) compatibility. A great many additives are being proposed today for use with hydrocarbons and HFCs.

This study examines the fundamental properties of various hydrohalocarbon and hydrocarbon blowing agents, and their relationship to solubility in polyurethane raw materials. The solubility of the various pentane isomers in many polyols and isocyanates used to produce insulation boardstock in a continuous lamination process is evaluated. The potential of many isocyanate modifications and polyol additives to improve blowing agent solubility is explored.

The effects of blowing agent solubility on the processing characteristics of foam properties are also examined. The data is used to examine the conventional theory regarding soluble systems - are such systems always necessary to get good processing? Many non-reactive or monofunctional additives that improve solubility are found to affect the structural, thermal or flammability performance of resulting foams. This paper presents data on potential methods to obtain robust processing and good perfonnance with the zero ODP blowing agents being considered by the rigid foam industry.

Get full access to this article

View all access options for this article.

References

1. Peterson

B.H.

, “Parameters Affecting the Compatibility of Alternative Blowing Agents in Polyols for Rigid Foam Formulations”; SPI Polyurethanes Expo 96, Las Vegas, USA.

2. Chittolini

, “Increasing the Solubility of Pentane in Rigid Foam Systems”; UTECH 96, The Hague, The Netherlands, Paper 56 (1996).

3. Frey

J.H.

Grimminger

Stevens

R.E.

, “New Silicone Surfactants for Rigid Polyurethane Foam”; UTECH 96. The Hague. The Netherlands, Paper 57 (1996).

4. Porter

M.R.

, Handbook of Surfactants. 2nd Ed., Blackie Academic &Professional, New York (1994).

5. Rosen

M.J.

, Surfactants and Interfacial Phenomena, 2nd Ed., John Wiley &Sons, New York (1988).

6. Myers

, Surfactant Science and Technology, 2nd Ed., VCH Publishers, Inc., New York (1992).

7. Singh

S.N.

Lynch

J.J.

Daems

, “Techniques to Assess the Various Factors Affecting the Long Term Dimensional Stability of Rigid Polyurethane Foam”; Proceedings of the SPI Polyurethanes 1995 Conference, Chicago, USA, p. 11 (1995).

8. Riley

R.E.

Fishback

T.L.

Yu-Hallada

L.C.

, “Flammability Study of Hydrocarbon-Blown Isocyanurate Foams'; Proceedings of the SPI Polyurethanes 1994 Conference. Boston USA. p.561 (1994).

9. Burns

S.B.

Schmidt

E.L.

, “The PIR/PUR Ratio: A Novel Trimer Conversion Test with High Correlation to the Factory Mutual Calorimeter for HCFC-141b Blown Polyisocyanurate Foams”; Proceedings of the Polyurethanes World Congress 1993, Vancouver, Canada, p. 234(1993).

10.

10. Bonapersona

Javarone

, “Development of CFC-Free Polyurethane-Modified Isocyanurate Foams with Improved Processability for Continuous Lamination”; UTECH 96. The Hague. The Netherlands, Paper 68 (1996).

11.

11. Nicola

W.J.

Weber

, “Improved Hydrocarbon Blown Foams for North America”; Proceedings of the SPI Polyurethanes 1995 Conference, Chicago. USA. p. 156 (1995).

12.

12. Castellan

G.W.

, Physical Chemistry. 2nd Ed. Addison-Wesley Publishing Company, California (1971).

13.

13. Griffin

W.C.

, in the Kirk-Otnmer Encyclopedia of Chemical Technology, 3rd Edition, Volume 8, p. 900 (1979).

14.

14. Griffin

W.C.

, “Classification of Surface Active Agents by HLB”; J. Soc. Cosmetic Chemists, p. 311 (1949).

15.

15.The HLB System: A Time-Saving Guide to Emulsifier Selection. ICI Surfactants, Wilmington, Delaware (1992).

16.

16.Ross Motionless Mixers. Ross Engineering. Inc., Savannah. Georgia. USA.

Method of Increasing the Solubility of Hydrocarbons and HFCs in Polyurethanes Raw Materials and the Effects on the Performance and Processing Characteristics of Construction Foams*

Abstract

Get full access to this article

References