The trans-polypentenamer has unique relevance among the synthetic rubbers since it has similar physical properties to the natural rubber. The polypentenamer additives have propitious effect on the tire properties and have been studied extensively for this application. Polypentenamer synthetic rubber was synthetized by ring-opening metathesis polymerization (ROMP) using ruthenium catalyst systems. It was found that the cyclopentene conversion does not depend on the catalyst activity and catalyst loading. However the applied reaction temperature has a significant impact on the polymerization yield. Equilibrium of growing chain and monomer was observed and the thermodynamic parameters were determined as: ?H = - 5.6 kcal � mol-1; ?S = -18.5 cal � mol-1� K-1. The effect of cyclopentene ring substituents on the equilibrium was also investigated by experimental and computational methods. The calculated and experimentally determined activation parameters of the synthetic rubbers made from different substituted cyclopentene derivatives are being determined. This unique feature of the equilibrium polymerization opens a way for the synthesis of durable, environmentally friendly elastomers where tires can be not only synthetized by the transition metal catalyst systems but the used tires can be readily decomposed by the same way and the recovered monomers can be easily recycled.  Figure 1. Ruthenium catalyzed ring-opening metathesis polymerization (ROMP) of cyclopentene.

Innovative synthetic rubbers via ruthenium catalyst systems

246th National Meeting (2013)

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