Poly(amic acid) and polyimide characterization using gas chromatography/mass spectrometry and particle beam liquid chromatography/mass spectrometry

Abstract

A number of polymers were hydrolyzed in NH4OH and studied using gas chromatography/ mass spectrometry (GC/MS) and particle beam liquid chromatography/mass spectrometry (particle beam LC/MS) techniques. The polymers studied in this report were as follows: BPDA-PDA, BPDA-PDA-ODA, BPDA-PDA-GFDA, PMDA-ODA, and BTDA-APB. Some of the polymer samples were hydrolyzed in both their acid and imide forms to see if any mass spectrometric differences could be detected. ln all cases, the acid and imide spectra looked the same. GC/MS was unable to determine either the amine or acid portion of these polymers via a direct injection of the sample, but when the samples were first extracted with diethyl ether and this ether extract was injected into the chromatograph, the amine portion of the polymers was readily detected. The acid portion was, again, not detected in either the sample or the ether extract. The particle beam was able to detect both the amine and acid monomeric units in the nonextracted sample.