Synthesis and Characterization of a Series of Alternating Copolymers (Oligomers) Containing Organophospha-lambda5-azene Backbone Moieties

摘要

The Staudinger reaction of bis(diphenylphosphino)alkyl or aryl compounds with 1,4-diazidobenzene at room temperature in benzene solution was shown to produce poly (organophospha (Lambda 5) azenes), which are alternating copolymers (oligomers) with the general formula (=P(Ph)2-R-P(Ph)2=N-C6H4-N=)n where R= (CH2)n, = 2-5, or R=p C6H4. The CP/MAS (13)C and (31)P NMR spectra were consistent with the proposed structures and showed a small amount of P=O end groups in addition to the P=N (31)P resonances. The diffuse reflectance FT-IR spectra showed the typical P=N absorptions characteristic of phospha Lambda 5 azenes along with some azido end group absorptions. The thermogravimetric analyses (TGA) of these polymers showed that they were reasonably thermally stable up to about 300 C, and differential scanning calorimetry (DSC) provided the glass transition temperatures, Tg. The Tg's for the polymethylene containing polymers were in the range 103-124 C and appeared to decrease with increasing length of the polymethylene chain. Approximate molecular weights of these insoluble polymers were obtained by end group analysis using the integrated areas from the (31)P NMR spectra (ratio of P=O and P=N groups) and assuming that P=O and N3 were the end groups. (aw)