To be honest, for the following my papers (free downloaded), the liquid monomers were purified by passing them through an alumina column for inhibitors removing, then exposed to vacuum distillation. ArticlePoly(DMAEMA-co-MPS) Coated Mesoporous Silica Nanoparticles a...
To be honest, for the following my papers (free downloaded), the liquid monomers were purified by passing them through an alumina column for inhibitors removing, then exposed to vacuum distillation. ArticlePoly(DMAEMA-co-MPS) Coated Mesoporous Silica Nanoparticles a...
Dear Mithra Inhibitors are the substances that can kill or inhibit the chain growth by combining with free radicals and forming either stable products or inactive free radicals. Inhibitors are added to monomers to prevent polymerisation during storage.
How remove the Inhibitors from the monomer? • For this the monomer is distilled or washed with an aqueous solution of sodium or potassium hydroxide. When the inhibitors is destroyed and removed by the aqueous phase. • In industrial practice, the inhibitors are killed by adding more quantities of initiators to the monomers.
Dear Mithra Inhibitors are the substances that can kill or inhibit the chain growth by combining with free radicals and forming either stable products or inactive free radicals. Inhibitors are added to monomers to prevent polymerisation during storage.
How remove the Inhibitors from the monomer? • For this the monomer is distilled or washed with an aqueous solution of sodium or potassium hydroxide. When the inhibitors is destroyed and removed by the aqueous phase. • In industrial practice, the inhibitors are killed by adding more quantities of initiators to the monomers.
The best way is told by Mr Ivan Gitsov, but it is not necessary to remove the inhibitor from the monomer, the polymerization will work with it but with a lower yield.
The best way is told by Mr Ivan Gitsov, but it is not necessary to remove the inhibitor from the monomer, the polymerization will work with it but with a lower yield.
Liquid monomers are always stabilized before shipping to increase their shelve-life. This is achieved by introducing few ppm of a radical-scavenging compound, usually a hidroquinone or catechol derivatives. It is usually taken off before polymerization, otherwise it will react with the free radical initiator at early time reducing hence their efficiency and concentration, so if it remains a part it will launch the polymerization but the conversion and ultimate molecular weight became unpredictable. To remove the inhibitor there are two major techniques used without any problems: - one is by passing the liquid monomer througn a column filled with silica or alumina gels - and the second is by washing with a concentrated solution of NaOH (4N), followed by drying (dehydrating agent) and sometimes distilled under reduced pressure To tell you, this situation is already discussed in the area of the researchgate.
Liquid monomers are always stabilized before shipping to increase their shelve-life. This is achieved by introducing few ppm of a radical-scavenging compound, usually a hidroquinone or catechol derivatives. It is usually taken off before polymerization, otherwise it will react with the free radical initiator at early time reducing hence their efficiency and concentration, so if it remains a part it will launch the polymerization but the conversion and ultimate molecular weight became unpredictable. To remove the inhibitor there are two major techniques used without any problems: - one is by passing the liquid monomer througn a column filled with silica or alumina gels - and the second is by washing with a concentrated solution of NaOH (4N), followed by drying (dehydrating agent) and sometimes distilled under reduced pressure To tell you, this situation is already discussed in the area of the researchgate.
Dear Omkar S. Kushwaha, the inhibitor is removed before the polymerization and not during it. It is a routine task in polymer Synthesis lab's. My Regards
Dear Omkar S. Kushwaha, the inhibitor is removed before the polymerization and not during it. It is a routine task in polymer Synthesis lab's. My Regards
Agreed that, It is not necessary to remove the inhibitor from acrylic acid monomer. But you should be careful about monomer needs to be in the acid form. In this way there wouldn't be much unreacted monomer. If you have any doubt about conversation, you can age the reaction a few hours more at 70-80 C. At higher pH the polymerization kinetic slows down and it becomes so difficult to polymerize.
Agreed that, It is not necessary to remove the inhibitor from acrylic acid monomer. But you should be careful about monomer needs to be in the acid form. In this way there wouldn't be much unreacted monomer. If you have any doubt about conversation, you can age the reaction a few hours more at 70-80 C. At higher pH the polymerization kinetic slows down and it becomes so difficult to polymerize.
Alternatively, you can buy Inhibitor removers and mix with monomer before polymerization. You will need to find the right inhibitor removers for your monomer.
Alternatively, you can buy Inhibitor removers and mix with monomer before polymerization. You will need to find the right inhibitor removers for your monomer.
The best method that works for us is a distillation under reduced pressure with copper wire, shavings or foil (clean, shiny surface is essential) in the distillation flask, not in the condenser or the receiving flask. In this way any radicals forming during the heating of the distillation flask are quenched. After the distillation you should store any unused portion at -4oC, but not for a long time. Good luck.
The best method that works for us is a distillation under reduced pressure with copper wire, shavings or foil (clean, shiny surface is essential) in the distillation flask, not in the condenser or the receiving flask. In this way any radicals forming during the heating of the distillation flask are quenched. After the distillation you should store any unused portion at -4oC, but not for a long time. Good luck.
What about the unreacted material left in the reaction vessel ?
What about the unreacted material left in the reaction vessel ?
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I Agree and recommend the methods described with Drs. Abdelkader BOUAZIZ , Ivan Gitsov , Inge-Willem Noordergraaf
To be honest, for the following my papers (free downloaded), the liquid monomers were purified by passing them through an alumina column for inhibitors removing, then exposed to vacuum distillation.
Article Poly(DMAEMA-co-MPS) Coated Mesoporous Silica Nanoparticles a...
Article Facile Synthesis of Poly(DMAEMA-co-MPS)-coated Porous Silica...
Best Wishes
I Agree and recommend the methods described with Drs. Abdelkader BOUAZIZ , Ivan Gitsov , Inge-Willem Noordergraaf
To be honest, for the following my papers (free downloaded), the liquid monomers were purified by passing them through an alumina column for inhibitors removing, then exposed to vacuum distillation.
Article Poly(DMAEMA-co-MPS) Coated Mesoporous Silica Nanoparticles a...
Article Facile Synthesis of Poly(DMAEMA-co-MPS)-coated Porous Silica...
Best Wishes
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Dear Mithra
Inhibitors are the substances that can kill or inhibit the chain growth by combining with free radicals and forming either stable products or inactive
free radicals. Inhibitors are added to monomers to prevent polymerisation
during storage.
How remove the Inhibitors from the monomer?
• For this the monomer is distilled or washed with an aqueous solution of
sodium or potassium hydroxide. When the inhibitors is destroyed and
removed by the aqueous phase.
• In industrial practice, the inhibitors are killed by adding more quantities of
initiators to the monomers.
Kind regards
Hani
Dear Mithra
Inhibitors are the substances that can kill or inhibit the chain growth by combining with free radicals and forming either stable products or inactive
free radicals. Inhibitors are added to monomers to prevent polymerisation
during storage.
How remove the Inhibitors from the monomer?
• For this the monomer is distilled or washed with an aqueous solution of
sodium or potassium hydroxide. When the inhibitors is destroyed and
removed by the aqueous phase.
• In industrial practice, the inhibitors are killed by adding more quantities of
initiators to the monomers.
Kind regards
Hani
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VOTE
The best way is told by Mr Ivan Gitsov, but it is not necessary to remove the inhibitor from the monomer, the polymerization will work with it but with a lower yield.
The best way is told by Mr Ivan Gitsov, but it is not necessary to remove the inhibitor from the monomer, the polymerization will work with it but with a lower yield.
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VOTE
Removal of inhibitors during the polymerization seems extremely challenging.
Removal of inhibitors during the polymerization seems extremely challenging.
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Liquid monomers are always stabilized before shipping to increase their shelve-life. This is achieved by introducing few ppm of a radical-scavenging compound, usually a hidroquinone or catechol derivatives. It is usually taken off before polymerization, otherwise it will react with the free radical initiator at early time reducing hence their efficiency and concentration, so if it remains a part it will launch the polymerization but the conversion and ultimate molecular weight became unpredictable.
To remove the inhibitor there are two major techniques used without any problems:
- one is by passing the liquid monomer througn a column filled with silica or alumina gels
- and the second is by washing with a concentrated solution of NaOH (4N), followed by drying (dehydrating agent) and sometimes distilled under reduced pressure
To tell you, this situation is already discussed in the area of the researchgate.
Liquid monomers are always stabilized before shipping to increase their shelve-life. This is achieved by introducing few ppm of a radical-scavenging compound, usually a hidroquinone or catechol derivatives. It is usually taken off before polymerization, otherwise it will react with the free radical initiator at early time reducing hence their efficiency and concentration, so if it remains a part it will launch the polymerization but the conversion and ultimate molecular weight became unpredictable.
To remove the inhibitor there are two major techniques used without any problems:
- one is by passing the liquid monomer througn a column filled with silica or alumina gels
- and the second is by washing with a concentrated solution of NaOH (4N), followed by drying (dehydrating agent) and sometimes distilled under reduced pressure
To tell you, this situation is already discussed in the area of the researchgate.
More
VOTE
Dear Omkar S. Kushwaha, the inhibitor is removed before the polymerization and not during it. It is a routine task in polymer Synthesis lab's. My Regards
Dear Omkar S. Kushwaha, the inhibitor is removed before the polymerization and not during it. It is a routine task in polymer Synthesis lab's. My Regards
More
VOTE
Agreed that, It is not necessary to remove the inhibitor from acrylic acid monomer. But you should be careful about monomer needs to be in the acid form. In this way there wouldn't be much unreacted monomer. If you have any doubt about conversation, you can age the reaction a few hours more at 70-80 C. At higher pH the polymerization kinetic slows down and it becomes so difficult to polymerize.
Agreed that, It is not necessary to remove the inhibitor from acrylic acid monomer. But you should be careful about monomer needs to be in the acid form. In this way there wouldn't be much unreacted monomer. If you have any doubt about conversation, you can age the reaction a few hours more at 70-80 C. At higher pH the polymerization kinetic slows down and it becomes so difficult to polymerize.
More
VOTE
Alternatively, you can buy Inhibitor removers and mix with monomer before polymerization. You will need to find the right inhibitor removers for your monomer.
Alternatively, you can buy Inhibitor removers and mix with monomer before polymerization. You will need to find the right inhibitor removers for your monomer.
More
VOTE
thank you all for the good comments .
thank you all for the good comments .
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monomer wash with 5% NaOH solution or vccum distilation
monomer wash with 5% NaOH solution or vccum distilation
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The best method that works for us is a distillation under reduced pressure with copper wire, shavings or foil (clean, shiny surface is essential) in the distillation flask, not in the condenser or the receiving flask. In this way any radicals forming during the heating of the distillation flask are quenched. After the distillation you should store any unused portion at -4oC, but not for a long time. Good luck.
The best method that works for us is a distillation under reduced pressure with copper wire, shavings or foil (clean, shiny surface is essential) in the distillation flask, not in the condenser or the receiving flask. In this way any radicals forming during the heating of the distillation flask are quenched. After the distillation you should store any unused portion at -4oC, but not for a long time. Good luck.
More
VOTE