COPOLYMERIZATION OF PROPENE AND HIGHER ALPHA-OLEFINS WITH THE METALLOCENE CATALYST ET[IND]2HFCL2 METHYLALUMINOXANE/

Copolymerizations of propene with higher alpha-olefins including 1-but ene, 1-hexene, 1-octene, 1-dodecene and 1-hexadecene were carried out with an isospecific metallocene catalyst (Et[Ind]2HfCl2/methylaluminox ane) at 30 degrees C in toluene. C-13 NMR analysis showed that all pro ducts obtained are random copolymers (r(1) . r(2) approximate to 1). T he reactivity of the higher cc-olefins in the copolymerization is surp risingly high and decreases only slightly with increasing length of th e olefin. The incorporation rates of the comonomers in this study were found to be much higher than those obtained by the use of heterogeneo us Ziegler-Natta catalysts. Hence, copolymers with every desired compo sition and alpha-olefin homopolymers can be prepared. The molecular we ight of the copolymers is reduced with rising comonomer content. Melti ng points and glass transition temperatures studied by means of differ ential scanning calorimetry show a decrease with rising comonomer cont ent and increasing length of the alpha-olefin.