Search results for "Ring-opening polymerization"

Glycidyl Tosylate: Polymerization of a “Non‐Polymerizable” Monomer permits Universal Post‐Functionalization of Polyethers

2019

Abstract Glycidyl tosylate appears to be a non‐polymerizable epoxide when nucleophilic initiators are used because of the excellent leaving group properties of the tosylate. However, using the monomer‐activated mechanism, this unusual monomer can be copolymerized with ethylene oxide (EO) and propylene oxide (PO), respectively, yielding copolymers with 7–25 % incorporated tosylate‐moieties. The microstructure of the copolymers was investigated via in situ 1H NMR spectroscopy, and the reactivity ratios of the copolymerizations have been determined. Quantitative nucleophilic substitution of the tosylate‐moiety is demonstrated for several examples. This new structure provides access to a librar…

New approach for synthesis of poly(ethylglyoxylate) using Maghnite-H + , an Algerian proton exchanged montmorillonite clay, as an eco-catalyst

2017

International audience; In this works, we have explored a new method for a green synthesis of poly(ethylglyoxylate) (PEtG). This method consists on using a montmorillonite clay called Maghnite-H+ as an eco-catalyst to replace triethylamine which is toxic. Cationic polymerization experiments are performed in bulk conditions at three temperatures (-40 degrees C, 25 degrees C, 80 degrees C) and in THF solutions at room temperature (25 degrees C). At 25 degrees C, an optimum ratio of 5 wt% of catalyst leads to molar masses up to 22000 g/mol in THF solutions. Polymerizations in bulk conditions lead to slightly lower masses than experiments conducted in THF solutions. However, bulk polymerization…

Synthesis and Characterization of Stimuli-Responsive Star-Like Polypept(o)ides: Introducing Biodegradable PeptoStars

2017

tar-like polymers are one of the smallest systems in the class of core crosslinked polymeric nanoparticles. This article reports on a versatile, straightforward synthesis of three-arm star-like polypept(o)ide (polysarcosine-block-polylysine) polymers, which are designed to be either stable or degradable at elevated levels of glutathione. Polypept(o)ides are a recently introduced class of polymers combining the stealth-like properties of the polypeptoid polysarcosine with the functionality of polypeptides, thus enabling the synthesis of materials completely based on endogenous amino acids. The star-like homo and block copolymers are synthesized by living nucleophilic ring opening polymerizat…

Some new examples of cationic polymerization

1986

Preparation, proprietes et polymerisation cationique de cis et trans-methoxyvinylchlorure. Le polymere trans est surtout threodiisotactique. Copolymerisation du cis avec le trans ou le styrene ou le dioxolanene-1,3. Polymerisation de la phenyl-2 oxazoline et de la conidine

Rapid Access to Polyfunctional Lipids with Complex Architecture via Oxyanionic Ring-Opening Polymerization

2011

Polymer-coated liposomes, particularly poly(ethylene glycol) (PEG)-substituted liposomes, have emerged as long-circulating carrier systems for drug delivery and diagnostic purposes. A rapid synthesis of three different types of multifunctional lipids with structurally diverse hydrophilic, polyether-based architectures via one- or two-pot approaches is described. Architectural variation is achieved by the combination of different oxyanionic polymerization strategies and various glycidyl ether building units. Branched polyglycerol lipids have been prepared via cholesterol- or 1,2-bis-n-alkyl glyceryl ether-initiated, oxyanionic ring-opening polymerization (ROP) of protected glycidyl ethers an…

Chiroptical Induction and Molecular Recognition in Optically Active Hyperbranched Polyethers with Inherently Chiral Benzophenone Core

2010

Poly(isoglycerol methacrylate)-b-poly(d or l-lactide) Copolymers: A Novel Hydrophilic Methacrylate as Building Block for Supramolecular Aggregates

2010

On the basis of a new acetal-protected glycerol monomethacrylate monomer (cis-1,3-benzylidene glycerol methacrylate/BGMA) a series of potentially biocompatible and partially biodegradable homo- and block copolymers were synthesized. ATRP polymerization of BGMA yielded well-defined polyacrylates with pendant benzylidene acetal groups and high glass transition temperatures (115−130 °C). This hydrophobic poly(cis-1,3-benzylidene glycerol methacrylate) could be readily transformed into the hydrophilic and water-soluble poly(1,3-dihydroxypropyl methacrylate), referred to as poly(isoglycerol methacrylate) (PIGMA). It exclusively contains primary hydroxyl groups and therefore differs significantly…

Multi-Arm Star Poly(L-lactide) with Hyperbranched Polyglycerol Core

2007

Biocompatible multi-arm star block copolymers based on poly(L-lactide) (PLLA) have been prepared by a core-first approach, using hyperbranched polyglycerol (PG), a polyether polyol, as a polyfunctional initiator. The molecular weight of the hyperbranched initiator-core was varied from 2 200 to 5 200 g mol -1 , molecular weights of the resulting multi-arm stars were in the range of 6 700-107 000 g mol -1 (NMR), depending on the amount of dilactide (LA) added. Various monomer/initiator ratios have been employed in the Sn-catalyzed LA polymerization in order to vary the length of the lactide arms from DP n (arm) = 2 to 20 units. Detailed NMR analysis using conventional and 2D-NMR techniques (e…

Homoleptic Phosphoraneiminato Complexes of Rare Earth Elements as Initiators for Ring-Opening Polymerization of Lactones.

2000

Cylindrical Polypeptide Brushes

2005

Cylindrical brushes with poly(L-lysine) and poly(L-glutamate) side chains were prepared by grafting through and grafting from techniques. Grafting from is shown to be more successful for the synthesis of cylindrical brushes with high molar mass main and side chains.