Polyol : Basics
As the name might indicate, Polyol is a macromolecule formed by polymerization of monomers. The final macromolecule has many alcohol functions (– O – H) considered to be the active sites.
Polyol could be formed by the polymerization of ethylene oxide monomers and / or propylene oxide monomers. The respective Polyol would be then called Polyether Polyol due to the ether function (– C – O – C –) that repeats within the molecule.
Polyol, on the other side could be called: Polyester Polyol, when monomers of di-alcohol and di-carboxylic acid react to form the macromolecules. The ester function (– COO –), then, could be found within the chain. This reaction results with elimination of water H2O.
The length of the chain, along with the number of chains that could be found in one macromolecule defines the physical characteristics of the resultant Polyol. The molecular weight of Polyol used in the production of Conventional Flexible Polyurethane Foam is usually between 3200 and 3600.
The functionality of Polyol refers to the number of free alcohol (– OH) site that could be found on the molecule. The theoretical number is generally 2 or 3 depending on the starting molecule where the chains are attached ending with 2 or 3 OH function at the end of the chains. Polyol, however, might have fractional functionalities instead of full digit figures. The main reason for the reduction of functionality is the presence of impurities that block the OH functions and then the average number of alcohol groups per molecule decreases.
Polyol could be formed by the polymerization of ethylene oxide monomers and / or propylene oxide monomers. The respective Polyol would be then called Polyether Polyol due to the ether function (– C – O – C –) that repeats within the molecule.
Polyol, on the other side could be called: Polyester Polyol, when monomers of di-alcohol and di-carboxylic acid react to form the macromolecules. The ester function (– COO –), then, could be found within the chain. This reaction results with elimination of water H2O.
The length of the chain, along with the number of chains that could be found in one macromolecule defines the physical characteristics of the resultant Polyol. The molecular weight of Polyol used in the production of Conventional Flexible Polyurethane Foam is usually between 3200 and 3600.
The functionality of Polyol refers to the number of free alcohol (– OH) site that could be found on the molecule. The theoretical number is generally 2 or 3 depending on the starting molecule where the chains are attached ending with 2 or 3 OH function at the end of the chains. Polyol, however, might have fractional functionalities instead of full digit figures. The main reason for the reduction of functionality is the presence of impurities that block the OH functions and then the average number of alcohol groups per molecule decreases.
posted by fadinajdi at 4:48 PM
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