Separation of components in epoxy resins degassing

[esteess]

Hi. Is that true the degassing an epoxy resin mixed with anhydride hardener may cause any sort of separation (molecular level???) that will affect the quality of the polymer?
This is what I heard but the source is not reliable.

 

[Compositepro]

It is theoretically possible, but very unlikely. Many organic materials, including epoxy resins can be vacuum distilled, meaning you can lose mass through boiling. The more volatile components would removed faster. A simple weight loss or volume loss measurement will reveal any problem. When I devolatilize a certain resin there may be a 15 gram weight loss from a gallon (3600 grams) after 30 minutes. In this time the resin goes from vigorous boiling at 100C and 20 Torr to barely bubbling at 6 Torr. The components being removed are impurities. Keep in mind that the vapor volume at 7.6 Torr is 100 times what it would be at 760 Torr. Also, when working at these low pressures it is essential to measure absolute pressure. Gauge pressure tells you very little of value.