Ring-opening homo- and copolymerization of lactones. Part 1. Homo- and copolymerization of racemic β-butyrolactone with ɛ-caprolactone and δ-valerolactone by tetraisobutyldialuminoxane (TIBAO) catalyst

Abstract

Copolymers of racemic β‐butyrolactone (β‐BL) with ε‐caprolactone (ε‐CL) (P(BL‐co‐CL)) and δ‐valerolactone (δ‐VL) (P(BL‐co‐VL)) were prepared by ring‐opening polymerization reactions using the commercial aluminoxane catalyst tetraisobutyldialuminoxane (TIBAO). The yields, molecular weights, compositions and crystallinities were determined for both copolymers by gel permeation chromatography (GPC), nuclear magnetic resonance (1H NMR) spectroscopy and differential scanning calorimetry (DSC). A detailed study by 13C NMR spectroscopy has been made to determine monomer diad sequence distributions. These results and those of reactivity ratios indicate that the co‐polymers may consist of compatible blocks of BL units and VL units of variable size. © 1998 SCI.

Chemistry, chances and limitations of the radical ring-opening polymerization of cyclic ketene acetals for the synthesis of degradable polyesters

“…Large number of commercially available biodegradable materials for medical and non-medical applications are based on polyesters like homopolymers or copolymers of glycolide, lactide, 3-caprolactone, and dioxanone etc. [2][3][4][5][6][7][8] In general, the conventional synthesis of these polyesters is either by ringopening polymerization of cyclic esters or by condensation polymerization (condensation of the diacids/diacid derivatives with diols) (Scheme 1). Lot of literature is already available and still increasing day by day on the use of different initiator systems like cationic, anionic and metal catalysts, as well as on Scheme 1 Conventional synthetic routes to polyesters: ring-opening polymerization of cyclic esters and condensation polymerization.…”

SmI2/Sm-Based γ-Buyrolactone−ε-Caprolactone Copolymers: Microstructural Characterization Using One- and Two-Dimensional NMR Spectroscopy

“…Generally, copolymerization of PCL is carried out for modifying its physical properties and for tuning its degradability behavior. Although the copolymerization behavior of CL with other comonomers like β-butyrolactone, valerolactone (VL), glycolide, and l -lactide − and nonhomopolymerizable cyclic monomers like γ-butyrolactone (BL) − and ethylene carbonate (EC) using different catalysts is available, but most of the reports have mentioned the configurational and compositional assignments of the comonomeric units in the polymer based on 1D 1 H and 13 C NMR techniques. The knowledge of microstructure is essential to understand the macroscopic characterization of the polymers as it directly affects the physicochemical and thermal properties.…”

Ring‐opening copolymerization of racemic β‐butyrolactone with ϵ‐caprolactone and δ‐valerolactone by distannoxane derivative catalysts: study of the enzymatic degradation in aerobic media of obtained copolymers

“…If we compare this result with the results of the biodegradation rate of polymer PHB synthesized in the presence of catalysts based of aluminium21, the highest initial biodegradation rates are obtained for synthetic polymers whose degree of isotacticity is close to 50%. In contrast, polymers tending to have isotactic structure (m = 0.70) or syndiotactic structure (m = 0.43) have very low biodegradation rates compared to the initial biodegradation rate of the bacterial PHB (100% R units).…”