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Is it possible to reverse polymerization in a 37% formaldehyde 14% methanol solution?
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+ Formaldehyde
+ Chemical engineering
+ Polymerization
+ Aldehydes
+ Acids
+ Chemistry
+ Methanol
+ Organic chemistry
Posted by
Lily
Is it possible to reverse polymerization in a 37% formaldehyde 14% methanol solution?
Happily, you asked to recover the methanol and not the NaBH4. The latter would have been a problem since borohydride slowly reacts with MeOH, releasing hydrogen gas. However, methanol is volatile and the boron species are not, so we can recover the methanol by vacuum distillation. In the laboratory you would put the mixture on a rotary evaporator and afterwards recover methanol from the solvent trap.
Happily, you asked to recover the methanol and not the NaBH4. The latter would have been a problem since borohydride slowly reacts with MeOH, releasing hydrogen gas. However, methanol is volatile and the boron species are not, so we can recover the methanol by vacuum distillation. In the laboratory you would put the mixture on a rotary evaporator and afterwards recover methanol from the solvent trap.
I’m going to go with a ‘no’ with this one. To “reverse” even the simplest polymer —ie where there is exactly regular branching, the monomers either must by their own virtues (eg polyethylene) or by imposition of some order (think all cis polystyrene or rubber vs gutta purcha) AND where there are no comonomers, polymerizations are almost always radical reactions, which don’t really undo themselves. (Even if you could homolyze a bond or — much more necessarily homolyze a whole bunch of bonds in your polymer, your most likely next step will be the coupling of whatever carbons have a lone electron that can get close enough to make a new bond). So I’d think you’d just get a harder plastic.
of course you have polymerizations that aren’t “plastic-making”, but these tend to have very specific uses, think cyanoacrylates, which undergo total polymerization in the presence of weak bases (like water) and require none of the usual ways to knock off a carbon electron (hv, metal catalysts etc) tend to soften in proper solvents, perhaps like you said (I usually pour acetone on my skin after I get superglue all over it but you might just be able to use yours, though formaldehyde plus skin equals not the most fun….unless you like vomiting from the smell but to each his own : ) ),
I’m going to go with a ‘no’ with this one. To “reverse” even the simplest polymer —ie where there is exactly regular branching, the monomers either must by their own virtues (eg polyethylene) or by imposition of some order (think all cis polystyrene or rubber vs gutta purcha) AND where there are no comonomers, polymerizations are almost always radical reactions, which don’t really undo themselves. (Even if you could homolyze a bond or — much more necessarily homolyze a whole bunch of bonds in your polymer, your most likely next step will be the coupling of whatever carbons have a lone electron that can get close enough to make a new bond). So I’d think you’d just get a harder plastic.
of course you have polymerizations that aren’t “plastic-making”, but these tend to have very specific uses, think cyanoacrylates, which undergo total polymerization in the presence of weak bases (like water) and require none of the usual ways to knock off a carbon electron (hv, metal catalysts etc) tend to soften in proper solvents, perhaps like you said (I usually pour acetone on my skin after I get superglue all over it but you might just be able to use yours, though formaldehyde plus skin equals not the most fun….unless you like vomiting from the smell but to each his own : ) ),
Happily, you asked to recover the methanol and not the NaBH4. The latter would have been a problem since borohydride slowly reacts with MeOH, releasing hydrogen gas. However, methanol is volatile and the boron species are not, so we can recover the methanol by vacuum distillation. In the laboratory you would put the mixture on a rotary evaporator and afterwards recover methanol from the solvent trap.
Happily, you asked to recover the methanol and not the NaBH4. The latter would have been a problem since borohydride slowly reacts with MeOH, releasing hydrogen gas. However, methanol is volatile and the boron species are not, so we can recover the methanol by vacuum distillation. In the laboratory you would put the mixture on a rotary evaporator and afterwards recover methanol from the solvent trap.
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I’m going to go with a ‘no’ with this one. To “reverse” even the simplest polymer —ie where there is exactly regular branching, the monomers either must by their own virtues (eg polyethylene) or by imposition of some order (think all cis polystyrene or rubber vs gutta purcha) AND where there are no comonomers, polymerizations are almost always radical reactions, which don’t really undo themselves. (Even if you could homolyze a bond or — much more necessarily homolyze a whole bunch of bonds in your polymer, your most likely next step will be the coupling of whatever carbons have a lone electron that can get close enough to make a new bond). So I’d think you’d just get a harder plastic.
of course you have polymerizations that aren’t “plastic-making”, but these tend to have very specific uses, think cyanoacrylates, which undergo total polymerization in the presence of weak bases (like water) and require none of the usual ways to knock off a carbon electron (hv, metal catalysts etc) tend to soften in proper solvents, perhaps like you said (I usually pour acetone on my skin after I get superglue all over it but you might just be able to use yours, though formaldehyde plus skin equals not the most fun….unless you like vomiting from the smell but to each his own : ) ),
I’m going to go with a ‘no’ with this one. To “reverse” even the simplest polymer —ie where there is exactly regular branching, the monomers either must by their own virtues (eg polyethylene) or by imposition of some order (think all cis polystyrene or rubber vs gutta purcha) AND where there are no comonomers, polymerizations are almost always radical reactions, which don’t really undo themselves. (Even if you could homolyze a bond or — much more necessarily homolyze a whole bunch of bonds in your polymer, your most likely next step will be the coupling of whatever carbons have a lone electron that can get close enough to make a new bond). So I’d think you’d just get a harder plastic.
of course you have polymerizations that aren’t “plastic-making”, but these tend to have very specific uses, think cyanoacrylates, which undergo total polymerization in the presence of weak bases (like water) and require none of the usual ways to knock off a carbon electron (hv, metal catalysts etc) tend to soften in proper solvents, perhaps like you said (I usually pour acetone on my skin after I get superglue all over it but you might just be able to use yours, though formaldehyde plus skin equals not the most fun….unless you like vomiting from the smell but to each his own : ) ),
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