Octafluorocyclopentene – A versatile tetrafunctional monomer for making tunable, high surface area, microporous ladder polymers

Abstract

Perfluoro, alicyclic, five membered organic compound, octafluorocyclopentene (OFCP) has been observed to yield insoluble microporous polymers with surface areas comparable to PIM-1. The surface area of microporous polymers depended on the ratio between A4 monomer, which was 5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethyl-1,1′-spirobisindane (THSBI), derived from tetraphenol and the tetrafunctional fluorinated B4 monomer, OFCP. The highest surface area of 824m2/g was obtained when the ratio of A4 to B4 was 0.75:1. The nitrogen adsorption-desorption isotherm of these microporous polymers was unique in that condensation of nitrogen gas was absent at high relative pressures unlike the majority of microporous polymers reported until now. Trapping of nitrogen gas was noticed at low partial pressures in the desorption isotherm of BET analysis. The pore volume was found to be one of the lowest reported for microporous polymers. SEM analysis showed rope like bundles for those polymers obtained by reacting A4 and B4 in equimolar quantities (1:1 ratio’s). OFCP is a versatile tetrafunctional fluorinated monomer capable of forming microporous polymers with 2 equivalents of dihydroxy aryl comonomer or with tetrafunctional A4 type comonomer at certain ratios thus enabling to tune the surface area of polymers. The reaction between mixed system of dihydroxy aryl compounds (BP-A/6F-BP-A) with spirobisindane and OFCP doesn't improve the polymers microporous surface areas compared to polymer synthesized between A4 and B4 comonomer combinations 0.75:1 ratio’s.