Synthesis of low molecular weight-hydroxy polycaprolactone macromonomers by coordinated anionic polymerization in protic conditions

Abstract

This article reports the development of a new catalytic process that takes advantage of the exchange reaction between aluminium alkoxides and alcohols to obtain functionalized low molecular weight oligomers by anionic ring-opening polymerization. The aluminium alkoxides can be used in homogeneous medium or grafted on a porous support to make possible a heterogeneous process. v-Hydroxy oligo polycaprolactones macromonomers with 2-hydroxyethylmethacrylate or hydroxymethylstyrene as polymerizable end groups have been synthesized and characterized by NMR and SEC. Mass spectrometry (LSIMS) has been used in an attempt to determine the MWD. These macromonomers have been engaged in copolymerization with styrene and the reactivity ratios have been approached.

Heterogeneous anionic ring opening polymerization in a fixed‐bed reactor: description of the process and modelling

“…It was performed in THF at 45 °C by using a Waters chromatograph equipped with a Shodex KF 805L column and a Waters 410 refractometer. Number‐average molecular weight could simply be determined by NMR spectroscopy3, 4, 14 (spectra recorded at 250 or 400 MHz in CDCl 3 ). In the case of polycaprolactone, molecular weight distributions (MWDs) were estimated using polystyrene standards and corrected according to the Mark–Houwink parameters for PCL, namely a = 0.786 and K = 1.395 × 10 −2 ml g −1 21…”

“…Practically speaking, polymerizations are almost exclusively carried out in homogeneous processes using a batch reactor according to a stoichiometric regime: the number of polymer chains is restricted to the number of metal atoms or alkoxide ligands, depending on the initiation efficiency. It has been found that adding transfer agents such as alcohols is a versatile way to increase the number of macromolecules as well as to obtain functionalized oligomers 11–14…”

Novel Macromolecular Architectures Based on Aliphatic Polyesters: Relevance of the “Coordination-Insertion” Ring-Opening Polymerization

“…Diblock copolymers have also been successfully prepared by sequential addition of the cyclic ether (EO) and lactone monomers using tetraphenylporphynato aluminum alkoxides or chloride as the initiator [69]. Of special interest is the heterogeneous catalytic coordination ROP process recently proposed by Hamaide et al [117][118][119]. The catalytic system was obtained by grafting alkyl aluminum moieties onto silica.…”

“…Not only tailor-made ω-func-tionalized oligomers but also random and block (oligo)copolymers have been produced. Note that a continuous process has been set up and that the recycling of the catalyst can be performed after washing the support [119]. Block copolymers of (R,S)-β-butyrolactone and εCL have been synthesized by combining the anionic ROP of the first monomer with the coordinative ROP of the second one (Scheme 15) [71].…”

New Amphiphilic Glycopolymers Based on a Polycaprolactone‐maleic anhydride Copolymer Backbone: Characterization by 15N NMR and Application to Colloidal Stabilization of Nanoparticles

“…[25,31] The polymerization proceeded according to a coordination-insertion mechanism. Aluminium isopropoxide was usually used as the initiator.…”