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What is the chemical formula for polyurethane? If it doesn’t have one, why not?
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Martin Lesley
What is the chemical formula for polyurethane? If it doesn’t have one, why not?
A Urethane has the formula: R’NH-CO-OR”. They are typically formed from an isocyanate ( R’-N=C=O ) and an alcohol. Polyurethanes use diisocyanates and diols. This gives each a unique R’ and R” structure.
A Urethane has the formula: R’NH-CO-OR”. They are typically formed from an isocyanate ( R’-N=C=O ) and an alcohol. Polyurethanes use diisocyanates and diols. This gives each a unique R’ and R” structure.
In their simplest form, polyurethanes are linear copolymers of diisocyanates O=C=N-R-N=C=O and diols HOR'OH, having [-CONHRNHCOOR'O-]n as a general formula. Since both R and R' can be several different groups, then a unique, well defined formula cannot be attributed to these copolymers. In addition, in real cases, things are less simple, because diols can be replaced by triols or polyols, so giving origin to more complex tridimensional structures, whose formula can be less easily represented.
In their simplest form, polyurethanes are linear copolymers of diisocyanates O=C=N-R-N=C=O and diols HOR'OH, having [-CONHRNHCOOR'O-]n as a general formula. Since both R and R' can be several different groups, then a unique, well defined formula cannot be attributed to these copolymers. In addition, in real cases, things are less simple, because diols can be replaced by triols or polyols, so giving origin to more complex tridimensional structures, whose formula can be less easily represented.
Wood is mostly cellulose, hemicellulose, and lignin. These are carbohydrates. Carbo ([math]C[/math]) hydrate ([math]H_2O[/math])
So what's the “[math]n[/math]”? It's a big number. Really big. Something in the millions. But it's different for every fiber of that wood.
Oh there are other elements in there, too. Calcium and sodium and nitrogen and chlorine just to name a few. But the bulk of what you see in a piece of wood is just three elements: C, H, and O.
Wood is mostly cellulose, hemicellulose, and lignin. These are carbohydrates. Carbo ([math]C[/math]) hydrate ([math]H_2O[/math])
So what's the “[math]n[/math]”? It's a big number. Really big. Something in the millions. But it's different for every fiber of that wood.
Oh there are other elements in there, too. Calcium and sodium and nitrogen and chlorine just to name a few. But the bulk of what you see in a piece of wood is just three elements: C, H, and O.
A Urethane has the formula: R’NH-CO-OR”. They are typically formed from an isocyanate ( R’-N=C=O ) and an alcohol. Polyurethanes use diisocyanates and diols. This gives each a unique R’ and R” structure.
A Urethane has the formula: R’NH-CO-OR”. They are typically formed from an isocyanate ( R’-N=C=O ) and an alcohol. Polyurethanes use diisocyanates and diols. This gives each a unique R’ and R” structure.
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In their simplest form, polyurethanes are linear copolymers of diisocyanates O=C=N-R-N=C=O and diols HOR'OH, having [-CONHRNHCOOR'O-]n as a general formula. Since both R and R' can be several different groups, then a unique, well defined formula cannot be attributed to these copolymers. In addition, in real cases, things are less simple, because diols can be replaced by triols or polyols, so giving origin to more complex tridimensional structures, whose formula can be less easily represented.
In their simplest form, polyurethanes are linear copolymers of diisocyanates O=C=N-R-N=C=O and diols HOR'OH, having [-CONHRNHCOOR'O-]n as a general formula. Since both R and R' can be several different groups, then a unique, well defined formula cannot be attributed to these copolymers. In addition, in real cases, things are less simple, because diols can be replaced by triols or polyols, so giving origin to more complex tridimensional structures, whose formula can be less easily represented.
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[math](CH_2O)n[/math]
Wood is mostly cellulose, hemicellulose, and lignin. These are carbohydrates. Carbo ([math]C[/math]) hydrate ([math]H_2O[/math])
So what's the “[math]n[/math]”? It's a big number. Really big. Something in the millions. But it's different for every fiber of that wood.
Oh there are other elements in there, too. Calcium and sodium and nitrogen and chlorine just to name a few. But the bulk of what you see in a piece of wood is just three elements: C, H, and O.
[math](CH_2O)n[/math]
Wood is mostly cellulose, hemicellulose, and lignin. These are carbohydrates. Carbo ([math]C[/math]) hydrate ([math]H_2O[/math])
So what's the “[math]n[/math]”? It's a big number. Really big. Something in the millions. But it's different for every fiber of that wood.
Oh there are other elements in there, too. Calcium and sodium and nitrogen and chlorine just to name a few. But the bulk of what you see in a piece of wood is just three elements: C, H, and O.
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Polyurethanes have no simple formula as they are made by a variety of ways.
Polyurethanes have no simple formula as they are made by a variety of ways.
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Polyurethane is a versatile polymer which can be fabricated into wide range of applications.
This thermoset polymer can be synthesized by reacting di isocyanates with polyols in prsence of catalyst or exposure to ultraviolet rays.
It can be further blown by blowing agent to make polyurethane foams
Polyurethane is a versatile polymer which can be fabricated into wide range of applications.
This thermoset polymer can be synthesized by reacting di isocyanates with polyols in prsence of catalyst or exposure to ultraviolet rays.
It can be further blown by blowing agent to make polyurethane foams
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The chemical equation for the formation of rust is:
Iron + Water + Oxygen = Rust
i.e. 4 Fe(s) + 6 H2O(l) + 3 O2(g) → 4 Fe(OH)3(s)
Then Fe(OH)3 dehydrates to produce Fe2O3.nH2O(s).
Thereby, the chemical formula for rust is Fe2O3.nH2O.
The chemical equation for the formation of rust is:
Iron + Water + Oxygen = Rust
i.e. 4 Fe(s) + 6 H2O(l) + 3 O2(g) → 4 Fe(OH)3(s)
Then Fe(OH)3 dehydrates to produce Fe2O3.nH2O(s).
Thereby, the chemical formula for rust is Fe2O3.nH2O.
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