Gradient copolymers of ε‐caprolactone and δ‐valerolactone via solvent‐free ring‐opening copolymerization with a pyridyl‐urea/MTBD system

Abstract

The ring‐opening copolymerization of ε‐caprolactone and δ‐valerolactone was carried out under solvent‐free conditions with a pyridyl‐urea (6C‐PU)/7‐methyl‐1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene catalytic system by premixing two monomers, yielding gradient copolyesters with cyclic and linear structures in the absence or presence of an initiator, respectively. The random and block copolyesters of these two monomers were also prepared for comparison. The results of 1H and 13C NMR spectra determined the linear and cyclic structure of copolymers. The kinetic experiment was used to determine the consuming rates of two monomers during the polymerization. The topologies and thermal properties of all the copolymers were characterized and compared by NMR and DSC.

Bifunctional and Recyclable Polyesters by Chemoselective Ring-Opening Polymerization of a δ-Lactone Derived from CO2 and Butadiene

“…Consequently, chemoselective ring-opening homopolymerization of EVP should provide opportunities for post-functionalization of polyesters, via hydrolysis, click reaction, and cross-linking, thus opening new avenues for the synthesis of CO2-based polymers with tailor-made structures and properties. [37][38] Using a synergistic organobase/urea binary catalytic system, [39][40][41][42] the chemoselective ROP of α-methylene-γ-butyrolactone (MBL) and α-methylene-δ-valerolactone (MVL) producing unsaturated polyesters has been achieved. [43][44] The anion generated by deprotonation of urea with the organobase effectively promotes the lactone ROP rather than the vinyl-addition polymerization of the exocyclic C=C double bond.…”

Analiza składu kopolimeru na podstawie symulacji małych układów reakcyjnych

“…Dotyczy to zwłaszcza procesów polimeryzacji, w których występują reakcje łańcuchowe ograniczające możliwość terminacji łańcucha polimerowego, np. żyjącej polimeryzacji anionowej [3], polimeryzacji z otwarciem pierścienia monomeru [4,5] oraz różnych wariantów kontrolowanej polimeryzacji rodnikowej [6][7][8].…”