Niyogi, Debdarsan and Kumar, R and Gandhi, KS (1999) Water blown free rise polyurethane foams. In: Polymer Engineering & Science, 31 (1). pp. 199-209.Full text not available from this repository. (Request a copy)
A model is developed in this work for predicting the bubble size distribution in polyurethane foams generated by using water as a chemical blowing agent. The model combines equations of energy balance, kinetics of the reactions of isocyanate with water and polyol, and nucleation and growth of $CO_2$ bubbles. It is found that as the water content of the reaction mixture is increased, the mean bubble size decreases and the bubble size distribution become narrower. Exactly the opposite occurs in polyurethanes foamed with a physical blowing agent, e.g., DuPont Freons. This suggests that a combination of physical and chemical blowing agents can be employed to control bubble size distribution.
|Item Type:||Journal Article|
|Additional Information:||The copyright belongs to Society of Plastics Engineers.|
|Department/Centre:||Division of Mechanical Sciences > Chemical Engineering|
|Date Deposited:||28 Mar 2006|
|Last Modified:||27 Aug 2008 11:51|
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