Synthesis of inorganic/organic host-guest hybrid materials by cationic vinyl polymerization within Y zeolites and MCM-41

Cationic guest polymerizations of several vinyl monomers inside the pores o f Hy zeolites and MCM-41 as hosts have been used for the synthesis of novel organic/inorganic hybrid materials. Substituted vinyl ethers [ROCH=CH2; R = -CH2CH(CH3)(2), -C2H5, -C2H4Cl, -C6H11], 2,3-dihydrofuran, and N-vinylcar bazole can serve this purpose, because their polymerization can be initiate d by the active protons in HY zeolite or by coadsorbed arylmethylium ions i n MCM-41. The synthesis of well-defined poly(vinyl ethers) or poly(vinylcar bazole) under the conditions of constricted geometry can be achieved by mea ns of cationic host-guest polymerization of the corresponding monomers in M CM-41 (pore diameter 3.6 nm) with (4-CH3OC6H4)(2)CHCl (MeO) or (C6H5)(3)CCl (TC) as the internal surface initiator. The reaction products are novel po lymer/MCM-41 host-guest hybrid materials. The molecular mass of the (enclos ed) polymer and the percentage of polymer within the pores of MCM-41 as wel l as HY zeolite can be adjusted within certain limits. Polymeric products a re analyzed by solid-state magic angle spinning cross-polarization C-13{H-1 } NMR spectroscopy and gel permeation chromatography analyses of the obtain ed polymer fraction after dissolution of the hybrid material in an aqueous potassium hydroxide solution. The formation of conjugated sequences of poly (vinyl ether) segments inside the HY zeolites is caused by successive ether cleavage along the encapsulated polymer chains.