Synthesis and characterization of poly(ɛ-caprolactone-co-ethylene glycol) star-type amphiphilic copolymers by “click” chemistry and ring-opening polymerization

Synthesis and Properties of Modified Biodegradable Polymers Based on Caprolactone

In this paper, the synthesis and characterization of two polycaprolactone-polydimethylsiloxane (PDMS-CL) copolymers with biodegradable properties are reported. A comparative study was carried out using an aminopropyl-terminated polydimethylsiloxane macro-initiator (APDMS) with two different molecular weights. The copolymers (PDMS-CL-1 and PDMS-CL-2) were obtained by ring-opening polymerization of ɛ-caprolactone using APDMS as initiators and stannous 2-ethylhexanoate as a catalyst. The copolymer's structures were confirmed by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (1H-NMR) spectra, and energy dispersion spectroscopy (EDX). Surface morphology was investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The hydrophobic properties of the copolymers were demonstrated by the water contact angle and water vapor sorption capacity. Additionally, biological tests were conducted on San Marzano type tomato plants (Lypercosium esculentum) to assess the synthesized copolymers' susceptibility to the environment in terms of biological stability and metabolic activity. The biodegradation of PDMS-CL-1 and PDMS-CL-2 copolymers does not have a dangerous effect on the metabolic activity of plants, which makes it a convenient product in interaction with the environment.

Synthesis and Self-Assembly of Poly(N-Vinylcaprolactam)-b-Poly(ε-Caprolactone) Block Copolymers via the Combination of RAFT/MADIX and Ring-Opening Polymerizations

Well-defined amphiphilic, biocompatible and partially biodegradable, thermo-responsive poly(N-vinylcaprolactam)-b-poly(ε-caprolactone) (PNVCL-b-PCL) block copolymers were synthesized by combining reversible addition-fragmentation chain transfer (RAFT) and ring-opening polymerizations (ROP). Poly(N-vinylcaprolactam) containing xanthate and hydroxyl end groups (X–PNVCL–OH) was first synthesized by RAFT/macromolecular design by the interchange of xanthates (RAFT/MADIX) polymerization of NVCL mediated by a chain transfer agent containing a hydroxyl function. The xanthate-end group was then removed from PNVCL by a radical-induced process. Finally, the hydroxyl end-capped PNVCL homopolymer was used as a macroinitiator in the ROP of ε-caprolactone (ε-CL) to obtain PNVCL-b-PCL block copolymers. These (co)polymers were characterized by Size Exclusion Chromatography (SEC), Fourier-Transform Infrared spectroscopy (FTIR), Proton Nuclear Magnetic Resonance spectroscopy (¹H NMR), UV–vis and Differential Scanning Calorimetry (DSC) measurements. The critical micelle concentration (CMC) of the block copolymers in aqueous solution measured by the fluorescence probe technique decreased with increasing the length of the hydrophobic block. However, dynamic light scattering (DLS) demonstrated that the size of the micelles increased with increasing the proportion of hydrophobic segments. The morphology observed by cryo-TEM demonstrated that the micelles have a pointed-oval-shape. UV–vis and DLS analyses showed that these block copolymers have a temperature-responsive behavior with a lower critical solution temperature (LCST) that could be tuned by varying the block copolymer composition.

Chitosan/poly(ε-caprolactone)-block-poly(ethylene glycol) copolymer electrospun membrane for the adsorption of dyes

The CS/PCL-(b-PEG) nanofibers with controllable core to shell ratio were fabricated as an adsorbent for dye adsorption.