Synthesis and characterization of carborane-containing poly(hydroxy ethers) with excellent thermal stability

o-Carborane-containing poly(hydroxy ethers) (P1,P2 and P3) were synthesized via "advancement reaction" of o-carborane-containing bisphenol (4) and diglycidyl ether of bisphenols (DGEBA and 1).FTIR and 1H-,13C-,and 11B-NMR were utilized to characterize the obtained polymers.TGA test was conducted under nitrogen and air.It is found that the shielding effect of carborane moiety on its adjacent aromatic structures contributes to high initial decomposition temperatures,while oxygen in air has an adverse effect on the initial decomposition temperature.The oxygen can combine with polymer chain to form peroxide and hydroperoxide groups,which are more reactive during the degradation process.Besides,o-carborane-containing poly(hydroxy ethers) have high char yield at elevated temperatures.The boron atom combines with oxygen from the polymer structure or/and from air,thus to form a three-dimensional network linked with B-O-B and B-C bonds,and retain the polymer weight to a large extent.