Summary: Ethylene was copolymerized with 1,7‐octadiene (OD) using a methylaluminoxane (MAO) activated constrained geometry catalyst (dimethylsilyl(N‐tert‐butylamido)(tetramethylcyclopentadienyl)titanium dichloride; CGC‐Ti) at 140 °C in toluene. The polymerization activity increased with the addition of small amounts of OD, reached a maximum, and then decreased at higher OD concentrations. The vinyl‐bond content of the polymers increased with increasing diene in the feed. Increasing OD concentrations led to the production of long chain branched (LCB) polyethylene (PE). Both 1,3‐cycloheptane (CY7) and 1,5‐cyclononane (CY9) units were identified in the copolymers, with the dominant CY9 structure accounting for approximately 53% percent of all rings. Selected copolymers were fractionated by molecular weight using a solvent/non‐solvent technique to obtain their detailed microstructure. The relative amounts of CY7 and CY9 structures were not a function of molecular weight. The number of vinyl functionalities decreased with increasing molecular weight, while the number of branches increased, indicating the incorporation of macromonomers with pendant or terminal vinyl groups.Molecular weight distributions of ethylene homopolymer and three fractions.magnified imageMolecular weight distributions of ethylene homopolymer and three fractions.

A series of graft polymers having polypropylene (PP) backbone and poly(ethylene-co-propylene) (EPR) side chains was prepared. PP backbone molecular weight (M n ) was 28 -98 kg/mol, EPR side chain M n was 2.6 -17 kg/mol, and EPR content was 0 -16 wt %. In this work, thermal analysis of the copolymers was performed using differential scanning calorimetry (DSC). Nonisothermal crystallization was performed at different cooling rates. The DSC thermograms revealed multiple melting peaks for slowly cooled samples, most likely the result of the melting of thinner tangential lamellae followed by the melting of thicker radial lamellae. Equilibrium melting temperature (T m 0 ) was determined using the linear Hoffman-Weeks method. Another approach was also used for determining