Polylactide-Based Materials: Synthesis and Biomedical Applications

Polylactide (PLA) is a biocompatible polyester that can be obtained by polycondensation of lactic acid or the ring-opening polymerization (ROP) of lactide [...

Multifunctional Membranes for Solvent Resistant Nanofiltration and Pervaporation Applications Based on Segmented Polymer Networks

Hydrophilic bis(acrylate)-terminated poly(ethylene oxide) was used as macromolecular cross-linker of different hydrophobic polyacrylates for the synthesis of amphiphilic segmented polymer networks (SPNs). Multifunctional composite membranes with thin SPN toplayers were prepared by in situ polymerization. As the Support consisted of hydrolyzed polyacrylonitrile, the high chemical resistance of the composite membrane allowed applications of the SPN-based membranes in solvent-resistant nanofiltration (SRNF) and pervaporation (PV). The membranes show very high retention on Rose Bengal (RB) in different solvents, especially in strong swelling solvents such as tetrahydrofuran (THF) and dimethylformamide (DMF). The membranes were also tested in pervaporation for dehydration of ethanol and isopropanol (IPA). The selectivity of the membranes greatly depends on the composition or the ratio of the hydrophilic and hydrophobic phases of the SPN

Biodegradable polymer networks via triazolinedione-crosslinking of oleyl-functionalized poly(epsilon-caprolactone)

The formation of biodegradable polymer networks by the crosslinking of tailor-made poly(epsilon-caprolactone) (PCL) via the ultrafast 1,2,4-triazoline-3,5-dione (TAD) chemistry has been demonstrated. First, a series of alpha,omega-oleyl terminated PCL was prepared by a two-step, one-pot synthesis that was initiated by the coordination ring opening polymerization of epsilon-caprolactone, resulting in prepolymers bearing both an oleyl and hydroxyl end group, which were subsequently coupled by means of a diisocyanate. Network formation was performed via Alder-ene reaction of two different bifunctional triazolinediones (bisTADs) with the oleyl end groups. Different crosslinking parameters were studied in order to find the optimal conditions for the preparation of sufficiently strong polymer networks. Besides the determination of thermal and mechanical properties, as well as the susceptibility to hydrolytic degradation, of the obtained PCL-network, also the influence of the PCL molecular weight, nature of the TAD crosslinker and crosslinking stoichiometry were determined

Combining cationic ring-opening polymerization and click chemistry for the design of functionalized polyurethanes

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Functional Polyesters with Pendant Double Bonds Prepared by Coordination–Insertion and Cationic Ring-Opening Copolymerizations of ε‑Caprolactone with Renewable Tulipalin A

The synthesis of functional copolyesters that contain pendant double bonds in their structures is reported by ring-opening copolymerization of renewable monomer Tulipalin A (α-methylene-γ-butyrolactone, MBL) and ε-caprolactone (CL) using either coordination–insertion or monomer activated mechanisms. Aluminum tris­(isopropoxide) (Al­(OⁱPr)₃) was successfully used as a cheap and commonly available catalyst for the coordination–insertion ring-opening copolymerization, and functional copolyesters with dispersities below 1.2 and with contents of MBL units in the copolymer up to 25 mol % were prepared. In addition, linear or multiarm copolymers of MBL with CL were synthesized by cationic ring-opening copolymerization that was conducted using protic acid as a “metal-free” catalyst in combination with mono- or multihydroxyl alcohols as initiators. The molecular characteristics and composition of the functional copolyesters were determined by GPC, NMR, two-dimensional NMR, and MALDI-TOF spectroscopy. The effect of MBL content on thermal properties of the copolyesters was investigated using DCS and TGA analyses. The availability of resulting functional copolyesters containing pendant double bonds toward postfunctionalization was demonstrated by either thermal or photochemical thiol–ene reactions with benzo­thioxanthene fluorophore or <i>N</i>-acetylcysteine, respectively