Mass spectral characteristics of poly(2,6‐dimethyl‐1,4‐phenylene ether)

The mass spectral characteristics of poly(2,6‐dimethyl‐1,4‐phenylene ether), its monomer (2,6‐xylenol), and its dimer (3,5‐dimethyl‐4‐hydroxyphenyl 2,6‐xylyl ether) have been determined. The monomer and dimer show peaks for the molecular ions (122; 242 amu) and degradation patterns similar to those of o ‐methylaryl ethers. Loss of methyl and cleavage of the ether with transfer of an o ‐methyl hydrogen are observed. Metastable transitions are recorded corresponding to a loss of 15 from 122 and 56 from 107 amu (xylenol) and of 151 from 242 and 40 from 104 amu (ether). The polymer volatilizes readily at 380–400°C. (TGA shows rapid weight loss at 400°C) and gives sets of peaks at ( N × 120) ± 14 up to 1080 ( N = 9). The principal peak is at ( N × 120) + 2, calibrated against PFA, and this is attributed to an ion of a volatilized oligomer. The oligomer is either present as such, is formed in a degradation process involving an ether redistribution, or is formed in a hydrogen transfer process in the ether cleavage reaction.