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The development of a simplified kinetic model describing some effects observed in catalyzed olefin terpolymerization is presented. Based on the method of moments, the model describes the influence of Al/V ratio and diene concentration on reaction yield and on polymer characteristics such as molecular weight, ethylene incorporation, and polydispersity. In order to verify the model validity, the terpolymerization reactions were performed using VOCl 3 -Al 2 Et 3 Cl 3 systems and 2-ethylidenebicyclo[2.2.1]hept-5-ene (ENB) as diene. The results of dynamic simulation fit well the experimental data for Al/V up to 15, but the model fails under high diene concentration, where branching reactions, neglected by reason of simplification, become significant.

The microstructure of polyolefinic thermoplastic elastomers made with a combination of two single‐site catalysts was analyzed by Monte Carlo simulation. The model can be used to describe the crystallizable fraction for both long‐chain branched polypropylene (aPP‐g‐iPP) and long‐chain branched ethylene/α‐olefin copolymers (PEαO‐g‐PE). The simulations showed that at levels of 7.5% of comonomer incorporation, PEαO‐g‐PE samples reach a similar crystallizability level of aPP‐g‐iPP. From a topological point of view, it was demonstrated that the fraction of free arms and inner segments tend to the limit of ½ for highly branched chains and that the fraction of free arms reaches its maximum value when the Y‐type chains are the predominant population. A mathematical correlation between the linear‐ and LCB catalyst probabilities was proposed to ensure the production of symmetrical branched chains.

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A series of ethylene-propylene-2-ethylidenebicyclo[2.2.1]hept-5-ene terpolymers have been prepared using the VOCl 3 /Al 2 Et 3 Cl 3 catalyst under various initial Al/V ratios and diene concentrations. The V/C and Al/V ratios in EPDM films were determined by Rutherford backscattering spectrometry. The concentration of incorporated vanadium increases with the increase of the iodine number, i.e., with the number of double bonds in the polymer. However, the concentration of incorporated V in the terpolymers remains relatively low, which is attributed to the small percentage of V(III) active species due to the presence of the diene. On the other hand, the Al/V molar ratio in the terpolymers was seen to be roughly constant (between 6 and 8), independent of the iodine number and of the initial Al/V molar ratio in the reaction mixture. The polymerization yield was seen to increase with the augmentation of the initial Al/V ratio and of the diene concentration, until reaching a maximum of about 500 g polymer/g V.