Search results for " copolymers"
showing 10 items of 65 documents
Synthesis of polybutadiene-polycaprolactone multi-blokcs based on hydroxyl telechelic polybutadiene. Composition and kinetic study
2009
International audience
Janus Nanostructures from ABC/B Triblock Terpolymer Blends
2019
Lamella-forming ABC triblock terpolymers are convenient building blocks for the synthesis of soft Janus nanoparticles (JNPs) by crosslinking the B domain that is &ldquo
Biocompatible polymeric micelles with polysorbate 80 for use in brain targeting.
2008
In this paper, the synthesis and characterization of novel amphiphilic graft copolymers based on an alpha,beta-poly(N-2-hydroxyethyl)-D, L-aspartamide (PHEA) backbone and D, L-polylactic acid (PLA) hydrophobic side chains are reported. These copolymers were obtained starting from PHEA-ethylenediamine (PHEA-EDA), which was functionalized with polysorbate 80 (PS(80)) and/or PLA in order to obtain the PHEA-EDA-PS(80)-PLA and PHEA-EDA-PLA samples, respectively. The degrees of derivatization, DD(PS80) and DD(PLA), of PHEA-EDA-PS80-PLA, calculated by (1)H-NMR, resulted in being 1.2 +/- 0.03 mol% and 0.54 +/- 0.05 mol%, respectively, while that of PHEA-EDA-PLA was found to be 0.60 +/- 0.05 mol%. S…
Synthesis, Characterization and Preliminary Biological Evaluation of P(HPMA)-b-P(LLA) Copolymers: A New Type of Functional Biocompatible Block Copoly…
2010
We describe a synthetic pathway to functional P(HPMA)-b-P(LLA) block copolymers. The synthesis relies on a combination of ring-opening polymerization of L-lactide, conversion into a chain transfer agent (CTA) for the RAFT polymerization of pentafluorophenyl methacrylate. A series of block copolymers was prepared that exhibited molecular weights $\overline M _{\rm n}$ ranging from 7 600 to 34 300 g · mol(-1) , with moderate PDI between 1.3 and 1.45. These reactive precursor polymers have been transformed into biocompatible P(HPMA)-b-P(LLA) copolymers and their fluorescently labeled derivatives by facile replacement of the pentafluorophenyl groups. The fluorescence label attached to this new …
Monomer Sequence Distribution Monitoring in Living Carbanionic Copolymerization by Real-Time 1H NMR Spectroscopy
2013
Detailed understanding of the monomer sequence distribution in carbanionic copolymerization was achieved by direct online monitoring of copolymerizations in an NMR tube. Obtaining detailed knowledge of the changing monomer concentration in stock during the reaction, this technique permits to determine the incorporation probability for each monomer at every position of the polymer chain. An in situ kinetic study of two different carbanionic copolymerizations has been carried out. On the one hand, the copolymerization of the structurally similar, protected hydroxystyrene derivatives, p-(1-ethoxy ethoxy)styrene (pEES) and 4-tert-butoxystyrene (tBuOS), and on the other hand the copolymerization…
New amphiphilic conjugates of mono- and bis(carboxy)-PEG(2,000) polymers with lipoamino acids as surface modifiers of colloidal drug carriers
2010
Hydrophilic and hydrophobic copolymers of a polyasparthylhydrazide bearing positive charges as vector for gene therapy
2008
BACKGROUND: The design of polymeric vectors for gene delivery provided with specific properties is one of the most critical aspects for a successful gene therapy. These polymers should be biocompatible as well as able to carry efficiently DNA to target tissues and to transfect it into cells. RESULTS: The formation of complexes of poly[(α,β-asparthylhydrazide)–poly(ethylene glycol)] and poly[(α,β-asparthylhydrazide)–hexadecylamine] copolymers functionalised with glycidyltrimethylammonium chloride (PAHy–PEG-GTA and PAHy–C16-GTA, respectively) with DNA was studied. The effects of the introduction of hydrophilic (PEG) or hydrophobic (C16) moieties on the chains of PAHy–GTA copolymers, such as t…
Synthesis and characterization of poly(L,L-lactide)-b-polyethylene glycol) diblock copolymers as plasticizers and their effect on the hydrophilicity …
2011
Vanadium catalysts for ethylene-norbornene copolymerization
2020
Kopolimery cyklicznych olefin (COCs) stanowią obiecującą grupę materiałów o specyficznych, możliwych do zaprojektowania właściwościach. Szczególnym zainteresowaniem w tej grupie związków cieszą się kopolimery etylenu z norbornenem. Do ich syntezy stosuje się różnorodne kompleksy metali przejściowych, przede wszystkim pierwiastków z grupy 4. Artykuł stanowi przegląd literatury dotyczącej wykorzystania katalizatorów wanadowych z różnego rodzaju ligandami w syntezie kopolimerów etylenu z norbornenem. Opisano wpływ ligandów i warunków prowadzenia reakcji na aktywność oraz wybrane właściwości otrzymanych kopolimerów.
Studies of ethylene/1-hexene copolymerization over zirconocene catalyst supported on MAO-modified MgCl2(THF)2. The effect of copolymerization conditi…
2003
Composition of catalytic system and copolymerization reaction conditions influence on heterogeneity of ethylene/1-hexene copolymers obtained over MgCI2(THF)2/MAO/Cp2ZrCl2/MAO catalyst was studied. One of the DSC techniques, i.e. successive self-nucleation/annealing (SSA) method allowing separation of the polymer into fractions with differing chemical composition in result of alternating crystallization and melting cycles was applied. It was found that the intermolecular heterogeneity exists inside all studied samples irrespective of the reaction conditions (temperature and time) and the catalyst composition (Al/Zr molar ratio). It was also confirmed that catalyst composition has a considera…