A NOVEL POLAR POLYMER VIA ROMP

We have synthesised poly(2,3-bis(trifluoromethyl)norbornadiene) (PBTFM ND) via ring-opening metathesis polymerisation (ROMP) to yield a glass y, highly polar polymer. The high trans polymer is similar to 92% tact ic and the high cis polymer is similar to 75% tactic but the type of t acticity cannot be determined by NMR techniques. Thermally Stimulated Depolarisation (TSD) measurements give relaxed susceptibilities as hig h as 45 for the high trans material but as low as 3 for the high cis m aterial. 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 temper ature permittivity and loss of PBTFMND results in a pyroelectric figur e of merit comparable with that of PVDF.