| Abstract
| - The chain structures of five ethylene/propylene copolymer samples with propylene molefractions of 0.277, 0.308, 0.321, 0.583, and 0.587 were analyzed and reported in this paper. These polymerswere synthesized in a solution continuous stirred-tank reactor (CSTR) at 130−150 °C using a constrainedgeometry catalyst (CGC). The copolymers had polydispersities close to 2. Inverted propylene units werepresent. A large number of long runs of polyethylene and polypropylene units were also observed.Increasing the propylene composition significantly increased the sequences of one and two methyleneunits and decreased those of six and more consecutive methylene units. However, the uninterruptedmethylene sequence distributions were little influenced by polymerization temperature. The meso andracemic contents in the continuous and inverted propylene units were approximately equal, indicatingthat the CGC did not have much control over the stereoregularity of the propylene insertion. Comparedto the vanadium ethylene propylene elastomers (EPM), the CGC EP copolymers had fewer alternatingcomonomer sequences and more consecutive ethylene and propylene units.
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