Important features of a Polyol

Important features of a Polyol

Molecular Weight

The more PO and EO molecules added to the glycerol initiator, the greater the molecular weight of the resulting polyol. The molecular weight of most polyols used for the production of slabstock foam is between 3000 and 6000. Increasing the molecular weight reduces the reactivity of the polyol. Furthermore it results in foam which has lower hardness and a higher tensile strength.

Functionality

The number of hydroxyl groups per molecule of initiator is referred to as the functionality. Glycerol has three hydroxyl groups, therefore the functionality of the final polyol is about 3 .In practice, certain side reactions usually result in functionality slightly below three.

Ethylene oxide Content

Polyols used for the production of of standard slabstock foam qualities can contain up to 20% EO. Increasing the amount of EO increases the reactivity of the polyol. The EO is usually distributed at random throughout the polyol chain. However, in special cases, the EO is present at the end of the polyol chains. These EO tipped polyols are more reactive than conventional polyol sans are used in specific applications such as the manufacture of high resilience foams.

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