Search results for "Caprolactone"
showing 10 items of 72 documents
Rapid One-Step Fabrication of Graphene Oxide-Decorated Polycaprolactone Three-Dimensional Templates for Water Treatment
2020
Coating of flexible substrates is crucial to prepare versatile, multifunctional materials. However, exploration of effective fabrication approaches is still a challenging issue, because the pathways generally proposed require time-consuming, multistep protocols. Here, we developed a one-pot process for decorating either pearl necklace-like or fibrous fluffy-like structures of polycaprolactone (PCL) with graphene oxide (GO) skin. PCL solutions were dry jet-wet electrosprayed or electrospun into a stirred liquid collector constituted by ethanol-containing GO nanoparticles. The stirred liquid collector enables the formation of 3D-structures, whose microarchitecture can be designed by controlli…
Diene/polar monomer copolymers, compatibilisers for polar/non-polar polymer blends. A controlled block copolymerisation with a single-site component …
2002
A well-controlled two-step process, the polymerisation of isoprene or isoprene/hex-1-ene copolymerisation followed by e-caprolactone polymerisation, affords trans-polyisoprene or (trans-polyisoprene/hex-1-ene copolymer)–poly(e-caprolactone) diblocks of various lengths. The single component initiator is an allylsamarocene compound. An atomic force microscopy study shows that these copolymers are efficient compatibilisers for poly(e-caprolactone) and polyisoprene blends. Poly(e-caprolactone) chain growth from Sm–polyisoprene chain.
Characterizations of Thermoplastic Block Elastomers Based on Polybutadiene and ε -Caprolactone
2010
A broad series of tri- and multiblock copolymers based on linear and branched oligomers of polybutadiene as central blocks and polycaprolactone (PCL) as block extremities are characterized by SEC, DSC, DMA, Dynamical Rheology and DRX. DSC analyses reveal phase separation between the two amorphous PB and PCL phases. By thermal analysis, the glass transition temperature of PCL is only detected for materials containing at least 80% w/w of PCL. This is attributed to the small length of the polyester blocks for copolymers containing less than 80% w/w of PCL. The increase of fusion heat with increasing PCL content in the copolymers is correlated to the greater ability of PCL chains to rearrange a…
Tunable release of Chlorhexidine from Polycaprolactone-based filaments containing graphene nanoplatelets
2019
Abstract Graphene nanoplatelets (GNP) as fillers and Chlorhexidine (CHX), as an antibacterial agent, were incorporated in a polycaprolactone (PCL) matrix and processed into filaments by melt spinning. The influence of both drawing and formulation on the processability, spinnability, mechanical properties and release behaviour of these materials were deeply investigated by performing rheological, morphological analysis, tensile tests, and by measuring the cumulative release of CHX in PBS at 37 °C. Furthermore, Korsmeyer–Peppas model was adopted to study the kinetics release mechanism. The results showed that adding GNP did not alter the processability and spinnability of the systems. Further…
Polycaprolactone-based scaffold for oil-selective sorption and improvement of bacteria activity for bioremediation of polluted water
2017
Abstract A novel floatable and biodegradable sponge for the selective absorption of oil from water and potentially useful as cell carrier for bioremediation treatments was prepared in polycaprolactone (PCL). The eco-friendly process for fabricating the PCL sponge does not involve either synthetic routes or organic solvents, thus minimizing environmental hazard. In particular, the 3D porous materials have been prepared by mixing in the melt the polymer matrix with two water-soluble porogen agents (NaCl and PEG) and thereafter leaching the obtained PCL/NaCl/PEG composites in water. The PCL sponges here proposed are capable to remove different types of oily pollutants (up to 500 wt%), and were…
Synthesis and degradation of poly (2-hydroxyethyl methacrylate)-graft-poly (ε-caprolactone) copolymers
2004
Abstract Poly (e-caprolactone) macromonomers carrying a methacryloyl end groups were synthesized using different lanthanide derivatives as catalysts, and characterized by SEC and 1 H NMR. Hydrophilic–hydrophobic copolymers from macromonomers and 2-hydroxyethyl methacrylate (HEMA) were obtained by solution free radical polymerization. Depending on the feed ratio of the two components, different copolymer structures were obtained. The expected graft structure of the copolymers was confirmed by 1 H NMR. Thermal properties of the copolymers were determined by DSC and TGA. Hydrolytic and enzymatic degradations of the materials were performed. Poly (2-hydroxyethyl methacrylate)- graft -poly (e-ca…
Polycaprolactone/gelatin-based scaffolds with tailored performance: in vitro and in vivo validation
2019
Abstract Nanofibrous scaffolds composed of polycaprolactone (PCL) and gelatin (Ge) were obtained through a hydrolytic assisted electrospinning process. The PCL-to-Ge proportion (100/0 to 20/80), as well as the dissolution time (24, 48, 72, 96, 120 h) into a 1:1 formic/acetic acid solvent before electrospinning were modified to obtain the different samples. A strong influence of these factors on the physicochemical properties of the scaffolds was observed. Higher Ge percentage reduced crystallinity, allowed a uniform morphology and increased water contact angle. The increase in the dissolution time considerably reduced the molar mass and, subsequently, fibre diameter and crystallinity were a…
1-n-Butyl-3-methylimidazolium-2-carboxylate: a versatile precatalyst for the ring-opening polymerization of ε-caprolactone and rac-lactide under solv…
2013
The ring-opening polymerization of ε-caprolactone (ε-CL) and rac-lactide (rac-LA) under solvent-free conditions and using 1-n-butyl-3-methylimidazolium-2-carboxylate (BMIM-2-CO2) as precatalyst is described. Linear and star-branched polyesters were synthesized by successive use of benzyl alcohol, ethylene glycol, glycerol and pentaerythritol as initiator alcohols, and the products were fully characterized by 1H and 13C{1H} NMR spectroscopy, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). BMIM-2-CO2 acts as an N-heterocyclic carbene precursor, resulting from in situ decarboxylation, either by heating under vacuo (method A) or by addition of NaBPh4 (method B)…
Mechanism of nanocapsules formation by the emulsion-diffusion process.
2007
International audience; A detailed investigation into the mechanisms of nanocapsule formation by means of the two stages “emulsion–diffusion” process is reported. Such widely used process is still poorly understood. An emulsion of oil, polymer and ethyl acetate is fabricated as a first step; dilution with pure water allows ethyl acetate to diffuse out from the droplets, leaving a suspension of nanocapsules at the end. It has been shown that the size of nanocapsules was related to the chemical composition of the organic phase and the size of primary emulsion through a simple geometrical relationship. As a consequence, most of the properties of the nanocapsules were decided at the emulsificat…
Production of polymeric micro- and nanostructures with tunable properties as pharmaceutical delivery systems
2020
Abstract The production of novel graft copolymers based on poly-e-caprolactone (PCL) and polyaspartamide are useful to realize structures for potential biomedical applications. Here, the synthesis of pegylated PCL/polyhydroxyethyl aspartamide (PHEA) graft copolymers (PHEA-g-SUCC-PCL-g-PEG) with tunable composition, was achieved by followpling a synthetic strategy that involved first the grafting of preformed PCL on PHEA backbone, then polyethylen glycol (PEG), by using 1,1′-carbonyldiimidazole (CDI) to speed up the condensation reaction. Graft copolymers with a Derivatization Degree (DD) in PCL ranging between 1.1 and 4.4 mol% were obtained, and processable with different technologies for t…