The purity of my monomers are 99.7% and 99.8%. We've tried mixing the solution for as long as 6 days to allow for every free diol to react. I've also tried monomer washes with acetone to try to wash out low molecular weight species. We just can't seem to get a polydispersity better than 4. This is polymerization using triphosgene. Any advice?
Unfortunately the diols are proprietary. But by HPLC area count they are >99.7% pure. I'm able to get sufficient MW, ca. 350KDa but the MN is always between 70-90KDa
Unfortunately the diols are proprietary. But by HPLC area count they are >99.7% pure. I'm able to get sufficient MW, ca. 350KDa but the MN is always between 70-90KDa
Please, look at this work
---Manufacture of polycarbonate using triphosgene involves dissolving phosgene in dichloromethane, reacting with bi-phenol A-sodium salt solution and then adding solid phosgene substance and modifier to reaction liquid
Patent Number: CN101195680-A
Patent Assignee: ZHAO Y
Inventor(s): ZHAO Y
Hope that you will find an answer there
Good luck
Alex, Please look at these too
---Polycondensations of bisphenol-A with diphosgene or triphosgene in water-free organic solventsBy: Kricheldorf, HR; Bohme, S; Schwarz, G
MACROMOLECULAR CHEMISTRY AND PHYSICS Volume: 206 (4), 432-438, 2005.
They claim that phosgene/diol ratio play a role on the molecular weight as well as open to cyclocarbonate ratio.
---Syntheses of cyclic polycarbonates by the direct phosgenation of bisphenol M
By: Kricheldorff, HR; Bohme, S; Schwarz, G; et al.
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY Volume: 43(6) 1248-1254, 2005.
Good luck
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