A novel polar polymer via ROMP

We have synthesised poly(2,3-bis(trifluoromethyl)norbornadiene) (PBTFMND) via ring-opening metathesis polymerisation (ROMP) to yield a glassy, highly polar polymer. The high trans polymer is similar to 92% tactic and the high cis polymer is similar to 75% tactic but the type of tacticity cannot be determined by NMR techniques. Thermally Stimulated Depolarisation (TSD) measurements give relaxed susceptibilities as high as 45 for the high trans material but as low as 3 for the high cis material. These data suggest that both the trans and cis materials are syndiotactic. The high trans material can be poled to yield a maximum polarisation of about 20 mC m(-2) and a pyroelectric coefficient of 6 mu C m(-2). Though this is less than that of PVDF, the low room temperature permittivity and loss of PBTFMND results in a pyroelectric figure of merit comparable with that of PVDF.