Unsaturated Copolyesters from Macrolactone/Norbornene: Toward Reaction Kinetics of Metathesis Copolymerization Using Ruthenium Carbene Catalysts

International Journal of Molecular Sciences

卷:23

Daniel Zárate-Saldaña¹  Arlette A. Santiago¹  Araceli Martínez¹  Joel Vargas² 

[1] Escuela Nacional de Estudios Superiores, Unidad Morelia, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No. 8701, Col. Ex. Hacienda de San José de la Huerta, Morelia C.P. 58190, Michoacán, Mexico;

[2] Instituto de Investigaciones en Materiales, Unidad Morelia, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No. 8701, Col. Ex. Hacienda de San José de la Huerta, Morelia C.P. 58190, Michoacán, Mexico;

关键词: ROMP;    macrolactones;    norbornene;    copolyesters;    ruthenium-carbene;   

DOI  :  10.3390/ijms23094521

来源: DOAJ

【 摘 要 】

Unsaturated copolyesters are of great interest in polymer science due to their broad potential applications and sustainability. Copolyesters were synthesized from the ring-opening metathesis copolymerization of ω-6-hexadecenlactone (HDL) and norbornene (NB) using ruthenium-alkylidene [Ru(Cl₂)(=CHPh)(1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)(PCy₃)] (Ru1), [Ru(Cl)₂(=CHPh)(PCy₃)₂] (Ru2), and ruthenium-vinylidene [RuCl₂(=C=CH(p-C₆H₄CF₃))(PCy₃)₂] (Ru3) catalysts, respectively, yielding HDL-NB copolymers with different ratios of the monomer HDL in the feed. The activity of N-heterocyclic-carbene (NHC) (Ru1) and phosphine (Ru2 and Ru3) ligands containing ruthenium-carbene catalysts were evaluated in the synthesis of copolymer HDL-NB. The catalysts Ru1 with an NHC ligand showed superior activity and stability over catalysts Ru2 and Ru3 bearing PCy₃ ligands. The incorporation of the monomers in the copolymers determined by ¹H-NMR spectroscopy was similar to that of the HDL-NB values in the feed. Experiments, at distinct monomer molar ratios, were carried out using the catalysts Ru1–Ru3 to determine the copolymerization reactivity constants by applying the Mayo–Lewis and Fineman–Ross methods. The copolymer distribution under equilibrium conditions was studied by the ¹³C NMR spectra, indicating that the copolymer HDL-NB is a gradient copolymer. The main factor determining the decrease in melting temperature is the inclusion of norbornene units, indicating that the PNB units permeate trough the HDL chains. The copolymers with different molar ratios [HDL]/[NB] have good thermal stability up to 411 °C in comparison with the homopolymer PHDL (384 °C). Further, the stress–strain measurements in tension for these copolymers depicted the appreciable increment in stress values as the NB content increases.

【 授权许可】

Unknown