Khoa,

Thermogravimetric analysis will give you the weight of inorganic fillers in the powder.  You may have to do chemical analysis of the organic portion of the powder to determine if there are organic compounds other than the polyester epoxy in the powder.  Infrared may work if the other compounds are present at concentrations above ~1%.  If the powder is soluble and the molecular of the polyester powder low enough gas chromatography/mass spectrometery may give you an indication of the other organic compounds (if there are any).

Dear John,

Thank you so much!

I used titration method to determine epoxy content in this power, but not enough because just being epoxy portion, I need determine both of polyester epoxy content.

Thank you again.

Dear John,

Thank you so much!

I used titration method to determine epoxy content in this power, but not enough because just being epoxy portion, I need determine both of polyester epoxy content.

Thank you again.

Khoa,

Do you have more information on your sample?  Is it a blend of epoxy and polyester?  What type of epoxy and polyester?

Dear John,

Unfortunately, I only know that is a powder blend of polyester epoxy, filler, additives... I don't know what type of epoxy.

Other way, if I use NMR to determine epoxy and polyester in this blend and use appropriate software to analyze %weight of this polymer in blend, is it possible?

Khoa,

Do you have a product name for the powder?  It is not clear to me from the information you have provided whether it is a physical blend of an epoxy and a polyester or an epoxidized polyester.