Effect of various catalyst systems

catalyst concentration and polymerization conditions on the catalytic efficiency (f) and molecular weight (Mn) of polyacetylene (PA) was investigated

it is found that larger amount of soluble fraction (q) of PA was obtained by catalyst systems Nd(i-OC3H7)3-AlR3 (R = C2H5-

i-C4H9). The catalyst concentration

Al/Nd molar ratio and polymerization temperature exert an influence on the f

Mn and q. UV spectra of soluble catalyst systems Nd(i-OC3H7)3-AlR3 confirmed that the valence state of Nd remains unchanged af-ter mixing it with AlR3.Results of IR spectra of PA showed that polymer obtained with Nd (i-OC3H7)-Al(C2H5)3 and Nd(i-OC3H7)3-Al(i-C3H9)3 contained CH3CH2-- and (CH3)2 CCH2-- end group respectively. The above mentioned results and the fact that CH2=CH-- end group was observed for polymers indicated that polymerization of acetylene with studied catalysts might be carried out through insertion of monomer between Nd-C bond.