The Unsaturated Polyester Via Ring-Opening Metathesis Polymerization (ROMP) of ω-6-Hexadecenlactone

Background: Ring opening metathesis polymerization of lactones using alkylidene catalysts is an alternative to obtain unsaturated linear polyesters with remarkable thermal and mechanical properties. Also, these polyesters have properties of biodegradability which opens up a wide range of applications as environmentally friendly thermoplastics and biomaterials. Objective: This research aims to present one route to obtain an unsaturated linear polyester poly(ω-6- hexadecenlactone) via ring opening-metathesis polymerization of ω-6-hexadecenlactone using the rutheniumalkylidene [Ru(Cl)2(=CHPh)(PCy3)2] (I), [Ru(Cl2)(=CHPh)(1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)( PCy3)] (II) and [Ru(Cl2)(=CH(o-isopropoxyphenylmethylene))(1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)] (III) and the ruthenium-vinylidene [RuCl2(=C=CH(p-C6H4CF3))(PCy3)2] (IV) catalysts. Conclusion: The high number-average molecular weights of the poly(ω-6-hexadecenlactone) between Mn = 114,800-155,400 g/mol and yields ranging from 96 to 98 % can be achieved by II and III catalysts. The catalysts II and III with the N-heterocyclic carbene ligand showed superior activity and stability upon catalysts I and IV bearing PCy3 ligands. The hydrogenation of poly(ω-6-hexadecenlactone) using Wilkinson catalyst [RhCl(PPh3)3] was studied. The percent crystallinity of the unsaturated poly(ω-6-hexadecenlactone) was 31% with a melting temperature 47.60ºC. Stress-strain measurements of several poly(ω-6-hexadecenlactone) were determined.