RAMAN-SPECTROSCOPIC STUDY OF THE FORMATION OF POLYACETYLENE WITHIN ZEOLITE CHANNELS

Raman spectroscopy has been employed to study the polymerisation of ac etylene on various zeolite substrates. Sodium mordenite (NaM) was dete rmined to be an inefficient catalyst. The majority of the acetylene in this system was found to be in the form of monomers which were bound in a 'side-on' fashion to cation sites within the main mordenite chann el. In contrast, caesium mordenite (CsM) samples facilitated the growt h of trans-polyacetylene to a far greater degree. Furthermore, the use of elevated pressures of acetylene was also found to be beneficial to polymer formation. Finally, pretreatment of CsM with CCl4 enhanced th e rate of polymer growth substantially. An explanation of these effect s is given.