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Polymeric Core (polymeric + core)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

A Novel Route to Thermosensitive Polymeric Core,Shell Aggregates and Hollow Spheres in Aqueous Media,

ADVANCED FUNCTIONAL MATERIALS, Issue 4 2005
Y. Zhang
Abstract Poly(,-caprolactone)/poly(N -isopropylacrylamide) (PCL/PNIPAM) core,shell particles are obtained by localizing the polymerization of NIPAM and crosslinker methylene bisacrylamide around the surface of PCL nanoparticles. The resultant particles are converted to hollow PNIPAM spheres by simply degrading the PCL core with an enzyme. The hollow spheres are thermosensitive and display a reversible swelling and de-swelling at ,,32,°C. [source]

Sequential Polymer Precipitation of Core,Shell Microstructured Composites with Giant Permittivity

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 5 2010
Tingyang Dai
Abstract Polymeric core,shell microstructures have been constructed through a new method, namely sequential precipitation, which is intrinsically a self-assembly and phase separation process. High-quality poly(vinyldene fluoride),polycarbonate,lithium perchlorate composite films with spherical core,shell microstructures have been prepared and determined to consist of conducting cores and insulating shells. Because of the percolation effect, the resulting materials present a dielectric constant as high as 104,107 at the threshold. [source]

Synthesis of polymeric core,shell particles using surface-initiated living free-radical polymerization

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 9 2007
Sarav B. Jhaveri
Abstract An easy and novel approach to the synthesis of functionalized nanostructured polymeric particles is reported. The surfactant-free emulsion polymerization of methyl methacrylate in the presence of the crosslinking reagent 2-ethyl-2-(hydroxy methyl)-1,3-propanediol trimethacrylate was used to in situ crosslink colloid micelles to produce stable, crosslinked polymeric particles (diameter size , 100,300 nm). A functionalized methacrylate monomer, 2-methacryloxyethyl-2,-bromoisobutyrate, containing a dormant atom transfer radical polymerization (ATRP) living free-radical initiator, which is termed an inimer (initiator/monomer), was added to the solution during the polymerization to functionalize the surface of the particles with ATRP initiator groups. The surface-initiated ATRP of different monomers was then carried out to produce core,shell-type polymeric nanostructures. This versatile technique can be easily employed for the design of a wide variety of polymeric shells surrounding a crosslinked core while keeping good control over the sizes of the nanostructures. The particles were characterized with scanning electron microscopy, transmission electron microscopy, optical microscopy, dynamic light scattering, and Raman spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1575,1584, 2007 [source]

Direct synthesis of amphiphilic block copolymers from glycidyl methacrylate and poly(ethylene glycol) by cationic ring-opening polymerization and supramolecular self-assembly thereof

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2005
Wei Huang
Abstract Amphiphilic block copolymers composed of a hydrophilic poly(ethylene glycol) (PEG) block and a hydrophobic poly(glycidyl methacrylate) (PGMA) block were synthesized through cationic ring-opening polymerization with PEG as the precursor. The model reactions indicated that the reactivity of the epoxy groups was higher than that of the double bonds in the bifunctional monomer glycidyl methacrylate (GMA) under the cationic polymerization conditions. Through the control of the reaction time in the synthesis of block copolymer PEG- b -PGMA, a linear GMA block was obtained through the ring-opening polymerization of epoxy groups, whereas the double bond in GMA remained unreacted. The results showed that the molecular weight of the PEG precursor had little influence on the grafting of GMA, and the PGMA blocks almost kept the same length, despite the difference of the PEG blocks. In addition, the PGMA blocks only consisted of several GMA units. The obtained amphiphilic PEG- b -PGMA block copolymers could form polymeric core,shell micelles by direct molecular self-assembly in water. The crosslinking of the PGMA core of the PEG- b -PGMA micelles, induced by ultraviolet radiation and heat instead of crosslinking agents, greatly increased the stability of the micelles. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2038,2047, 2005 [source]

Photoswitchable architectural polymer: Toward azo-based polyamidoamine side-chain dendritic polyester

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 23 2001
Samaresh Ghosh
Abstract A versatile approach to the synthesis of novel polyamidoamine (PAMAM) side-chain dendritic polyester (SCDPE) possessing azobenzene motifs in the polymeric core is described and displayed reversible cis,trans (E/Z) isomerization upon exposure to UV light. A polymerization reaction was conducted in solution using ester-terminated PAMAM dendritic diol (1a, G 3.5) and azobenzene dicarboxylic acid chloride in the presence of triethylamine. PAMAM dendritic diol 1a as well as SCDPE (1) were thoroughly characterized by means of IR and NMR (1H and 13C) spectroscopies. The intrinsic viscosity of 1 at 36 °C in CHCl3 was found to be 0.38 dl/g. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4182,4188, 2001 [source]

Self-Assembly of Dendritic Macromolecules Based on the Ionic Interaction of Linear Chain Polyelectrolyte Cores with Oppositely Charged Focal Ionogenic Groups of Dendrons

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 12 2004
Alexander Y. Bilibin
Abstract Summary: A new principle for the design of dendritic macromolecules , the ionic binding of linear chain polyelectrolyte with oppositely charged focal ionogenic groups of dendrons , has been developed. The majority of the dendritic ionic complexes (DICs) are prepared with poly(styrenesulfonic acid) (PSS) as a polymeric core and L -aspartic acid dendrons of different generations. Two series of DICs were prepared using PSS and aspartic dendrons bearing terminal (located at the external periphery) methoxycarbonyl and hexyloxycarbonyl groups (C1- n and C6- n respectively where n is the generation number). Ionic binding of about 100% was found for dendrons of Generation 1,3. The solubility of the DICs was examined and the DICs prepared were studied by IR spectroscopy, 1H NMR and viscometry. Dendritic ionic complexes prepared using poly(styrenesulfonic acid) acid and aspartic dendrons bearing terminal methoxycarbonyl and hexyloxycarbonyl groups. [source]