Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.
-
Upload
gwendolyn-holmes -
Category
Documents
-
view
224 -
download
0
Transcript of Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.
![Page 1: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/1.jpg)
Doing without Phosgene, Hydrogen Cyanide, and FormaldehydePART II
![Page 2: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/2.jpg)
Reducing Toxicity of Isocyanates
toluenediisocyanate
Isocyanates
- Associated with occupational asthma;
- Require a hood;
Ways to reduce toxicity:
-Increasing MW;
- Chemical conversion;
![Page 3: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/3.jpg)
Chemical Conversion of Isocyanates
1. Conversion to carbodiimides
2. Reaction with polymeric diol
RNCO
![Page 4: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/4.jpg)
Various HA Agents Can Add to Isocyanate Group
RNHCOAHARNCO
nRNHOCORNCOROCNOHRHO ))((
nRNHONHCRNCOROCNNHRNH ))((22
alchohol
isocyanate
isocyanate polyurethane
polyureaamine
• -used to inactivate isocyanate group
• -require thermal unblocking
• -volatile blocking agent
![Page 5: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/5.jpg)
Blocked Prepolymer Mixtures
Tengfei Shen, Mangeng Lu, Liyan Liang; Synthesis and properties of biodegradable polyurethane crosslinkers from methyl ethyl ketoxime-blocked diisocyanate. Macromolecular Research, August 2012, Volume 20, Issue 8, pp 827-834
Methyl ethyl ketoxime
![Page 6: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/6.jpg)
Thermally Reversible Polyurethane Polymers
Dissociation Temperature
Alcohol > Lactam > phenol > ketoxime >active methylene compound
1,4-butanediol
4,4-diphenyldiisocyanate
4,4’-isopropylidendipenol (bisphenol A, BPA)
![Page 7: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/7.jpg)
4,4’-Isopropylidendipenol (bisphenol A, BPA)
http://www.edf.org/health/four-reasons-bpa-free-wont-protect-you?s_src=ggad&s_subsrc=bpa&gclid=CM_c2IT1wsACFaTm7Aodo1cA2Q
![Page 8: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/8.jpg)
Polymerization of Isocyanate Monomers
![Page 9: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/9.jpg)
Polymers Made without Isocyanates: Reactions of Cyclic Carbonates with Diamines
Contras: low MW (9350 and 5345) Possible solution: use chain extension agents
![Page 10: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/10.jpg)
Reactions of Cyclic Carbonates with Diamines
![Page 11: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/11.jpg)
Applications of Polycarbonate Polymers
http://www.bisphenol-a-europe.org/uploads/images/EN_Socio-economic-contribution_011013-2_08.png
http://atlasthermoforming.com.au/wp-content/gallery/poly-carb/polycarbonate_chair.png
http://www.metalandpolycarbonatesheets.com/durotuff/polycarbonate-sheet-1.jpg
http://gallinausa.com/wp-content/uploads/2012/02/547.photo_.c.jpg
![Page 12: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/12.jpg)
PolycarbonatesTraditional polycarbonate synthesis involves phosgene
Solvent: methylene chlorideBase: pyridine, NaOH
![Page 13: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/13.jpg)
Ester Exchange Method for Polycarbonate Synthesis
http://chem.chem.rochester.edu/~chem424/pcsynth.htm
No solvents, no salt by-productsNeeds:High temperatureVacuum/N2 flow to extract phenol
![Page 14: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/14.jpg)
CO2 Can Be an Alternative to CO in Polycarbonates Synthesis
![Page 15: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/15.jpg)
Summary for PhosgeneElimination of phosgene in PC production is getting commercialized (SABIC, Asahi, Mitsubishi)
Non-Phosgene Polycarbonate from CO2 - Industrialization of Green Chemical ProcessAuthors: Shinsuke Fukuoka (Asahi Kasei Chemicals Corporation) Chapter 1. Introduction: Society And Chemical Industry
Chapter 2. Background Of Polycarbonate Chapter 3. General Method For Synthesis Of Polycarbonate Chapter 4. Technological Aspects Of The Industrial Processes For Producing Aromatic Polycarbonates Using Carbon Monoxide (Co) As A Starting Material
Part 1. Interfacial Polycondensation Phosgene Process Chapter 5. Technological Aspects Of The Industrial Processes For Producing Aromatic Polycarbonates Using Carbon Monoxide (Co) As A Starting Material
Part 2. Non-phosgene Process Chapter 6. General Aspect Of Non-Phosgene Polycarbonate Process From Co2 (Asahi Kasei Process) Chapter 7. Monomer Production Technology From Co2 (Asahi Kasei Process) Chapter 8. Melt Polymerization Technology Of Asahi Kasei Process Chapter 9. Excellent Features Of Polycarbonate Produced By Asahi Kasei Non-Phosgene Process Chapter 10. Economical Features Of Asahi Kasei Non-Phosgene Polycarbonate Process Chapter 11. Contribution Of Asahi Kasei Non-Phosgene Polycarbonate Process To Society
Chapter 12. Other Approach 1 – Outline Of Chemical Fixation Of Co2 Into Polymer Chapter 13. Other Approach 2 – Development Of Non-Phosgene Mdi Process
![Page 16: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/16.jpg)
Summary for Phosgene
Polyurethane Synthesis
- Elimination of phosgene from isocyanate synthesis
- Methyl isocyanate synthesis on demand (DuPont)
- Advances in pest management to eliminate carbamates
Challenge:
- On demand production of other isocyanates
- Create similar products synthetized from less harmful materials
![Page 17: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/17.jpg)
General Toxicity Rules for Safer Substitutions• CO2 is less toxic than CO
• Ethanol is less toxic than methanol
• Aliphatic amines are less toxic than aromatic and nitro aromatic compaunds
• Routs to amines through diols are less toxic than through nitriles
• Higher MW substance is less toxic that low MW substance
• Roots via carboxylic acid are less toxic than via nitro compounds
• Solids give less problems than liquids
![Page 18: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/18.jpg)
Replacements for HCN
1. Replacements in gold ore extraction
- Thiourea (can be reused)/ thiourea + Fe(III) sulfate in ionic liquid
- Chloride on activated carbon
2. Replacements in adipic acid synthesis
- Renewable raw materials (petroselenic acid, cis-muconic acid
![Page 19: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/19.jpg)
Elimination of FormaldehydePhenol-formaldehyde and urea-formaldehyde adhesives for the plywood and particle board
![Page 20: Doing without Phosgene, Hydrogen Cyanide, and Formaldehyde PART II.](https://reader034.fdocuments.us/reader034/viewer/2022051315/56649d6f5503460f94a516f6/html5/thumbnails/20.jpg)
Elimination of FormaldehydeCrease proofing resin for cottonBeing replaced by 1,2,3,4-butanetetracarboxylic acid and poly(maleic acid)
http://oecotextiles.wordpress.com/2011/01/04/formaldehyde-in-your-fabrics/