Alex Joseph Crotteau

6 Questions 19 Answers 0 Followers

Questions related from Alex Joseph Crotteau

How will secondary alcohols and carboxylic acids react with triphosgene during a polymerization?

I am performing solution polymerization of diols (PLLA diols have a secondary alcohols, and can also have trace carboxylic acid endgroups) using triphosgene. I am continuing to have problems with...

09 September 2014 8,640 1 View

Does anyone have any experience with triphosgene making anhydrides?

I am running polycondensations with triphosgene and diols and have noticed degradation of the final powder that is much faster than normal. Anhydride bonds are obviously not as thermally stable as...

08 August 2014 8,457 2 View

How will carboxylic acids affect my phosgenation of diols?

So I am taking diols, dissolving them into chloroform and pyridine, and adding a solution of chloroform/triphosgene to the reaction over a period of time. I am failing to get a high number average...

08 August 2014 2,076 5 View

What causes the exothermic reaction that occurs when mixing triethlyamine with a polycarbonate?

So I am having trouble with the solubilty of my polycarbonate. We make these using diols and triphosgene in chloroform solution with a large molar excess of pyridine. I wanted to know if using TEA...

08 August 2014 7,557 7 View

Does anyone have any good ideas on how to raise the Mn of a polycarbonate?

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...

01 January 2014 1,392 6 View

I am trying to find out what formulation they are using in their BVS stent, does anyone work for/with Abbotts BVS program?

So Abbotts BVS cornary stent is make of extruded and then blowformed PLLA. But I have a suspicion that they use mandelic acid monomer or polymandelide in there commercial stent as a reinforcement...

01 January 2014 6,294 0 View