			Home About us Contact

Interfacial Polymerization (interfacial + polymerization)

Distribution by Scientific Domains

Polymers and Materials Science	88%
Chemistry	11%

Selected Abstracts

Interfacial polymerization of morphologically modified polyaniline: from hollow microspheres to nanowires

POLYMER INTERNATIONAL, Issue 2 2008
Jinbo Li
Abstract BACKGROUND: Polyaniline (PANI) has attracted much attention in many fields due to its chemical and physical properties, and different nanostructures of PANI changing from one-dimensional to three-dimensional have been obtained. By changing the concentration of cetyltrimethylammonium bromide (CTAB), the morphology of hydrochloric acid-doped polyaniline could be changed from one-dimensional nanoneedles or nanowires with a network structure (50,100 nm in diameter) to three-dimensional hollow microspheres (ca 400 nm in outer diameter) via combining interfacial polymerization and self-assembly process. RESULTS These different nanostructures of PANI were proved using scanning electron and transmission electron microscopies. A plausible mechanism of the formation of the changeable nanostructures of PANI may be different from that of interfacial polymerization without surfactant or a traditional homogenous reaction system using CTAB as surfactant. CONCLUSION The results obtained from Fourier transform infrared spectrometry, X-ray diffraction and the four-probe method showed that the molecular structure of PANI does not change with increasing CTAB concentration, but crystallinity and conductivity of PANI increase with surfactant concentration. Copyright © 2007 Society of Chemical Industry [source]

Helical polyacetylene,Origins and synthesis

THE CHEMICAL RECORD, Issue 6 2008
Kazuo Akagi
Abstract We present the origins and synthesis of helical polyacetylene (H-PA) by focusing on its peculiar spiral morphology. Interfacial polymerization of acetylene was carried out in an asymmetric reaction field consisting of chiral nematic liquid crystal (N*-LC) and Ziegler,Natta catalyst. As the N*-LC is composed of nematic liquid crystal and a chiral compound such as a binaphthyl derivative with either the R - or S -configuration, the screw directions of the polyacetylene chain and fibril bundle,and even the spiral morphology,are rigorously controlled by the chirality of the selected compound. Interestingly, the screw directions of the fibril and the bundle in H-PA were found to be opposite to that of N*-LC. It is worthwhile to emphasize that the hierarchical spiral morphology involving the primary to higher order structure is generated in a synthetic polymer such as polyacetylene by using N*-LC as an asymmetric polymerization solvent. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 395,406; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20163 [source]

Monodisperse Polymer Capsules: Tailoring Size, Shell Thickness, and Hydrophobic Cargo Loading via Emulsion Templating

ADVANCED FUNCTIONAL MATERIALS, Issue 10 2010
Jiwei Cui
Abstract The preparation of monodisperse polymer (polydopamine, PDA) capsules by a one-step interfacial polymerization of dopamine onto dimethyldiethoxysilane (DMDES) emulsion droplets and removal of the DMDES templates with ethanol is reported. The diameters of the PDA capsules can be tailored from 400,nm to 2.4,µm by varying either the DMDES emulsion condensation time or the emulsion concentration used for templating. Further, capsules with defined nanometer-scale shell thicknesses (ranging from ,10 to 30,nm) can be prepared by adjusting the emulsion concentration. This shell thickness can be increased by repeated interfacial polymerization of dopamine, with three cycles yielding capsules with a shell thickness of up to 140,nm (for a 0.6% v/v suspension). Functional substances, such as organically stabilized magnetic (Fe3O4) nanoparticles, quantum dots (CdSe/CdS), and hydrophobic drugs (thiocoraline), can be preloaded in the emulsion droplets, and following PDA coating and DMDES removal, these materials remain encapsulated in the polymer capsules. All of the unloaded and loaded PDA capsules are monodisperse and do not aggregate. This work provides new avenues for the preparation of polymer capsules with defined size and shell thickness and for the encapsulation of a range of hydrophobic substances. [source]

Interfacial formation of porous membranes with poly(ethylene glycol) in a microfluidic environment

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2008
Dongshin Kim
Abstract In a microfluidic environment, the liquid,liquid interface, formed by laminar flows of immiscible solutions, can be used to generate thin membranes via interfacial polymerization. Because these thin nylon membranes have a very small pore size or lack porosity entirely, their utilization in some biological applications is greatly limited. We introduce an in situ fabrication method using the interfacial reaction of a two-phase system to generate a porous nylon membrane. The membranes were characterized with scanning electron microscopy and fluorescent beads. Scanning electron microscopy micrographs verified the asymmetrical structure of the porous membrane, and the membrane pore sizes ranged from 0.1 to 1 ,m. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008. [source]

Fabrication of DBSA-doped polyaniline nanorods by interfacial polymerization

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008
Shihai Ding
Abstract An interfacial polymerization was used to fabricate dodecybenzenesulfonic acid (DBSA)-doped polyaniline (DBSA-PANI) nanorods with diameter range from 40 nm to 1 ,m. The molar ratio of aniline to ammonium peroxydisulfate (APS), the concentrations of DBSA and reaction temperature had an effect on the morphology and size of products. It was found that lower concentration of DBSA and lower temperature will be helpful to the formation of rod-like PANI nanostructures with a relative small diameter. UV,vis and FTIR measurements were used to characterize the chemical structure of the obtained samples. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

Polyamides nanocapsules: Modeling and wall thickness estimation

AICHE JOURNAL, Issue 6 2006
K. Bouchemal
Abstract This work provides a better understanding for effective control of the nanocapsules wall thickness. Polyamides based nanocapsules are prepared by interfacial polymerization combined with spontaneous emulsification. A clear guideline of how factors such as monomer concentration, diffusion, interfacial reaction, or water swelling influence the capsule formation is very important to the control of capsule wall structure and release performance. In this goal, the macroscopic planar models of the interfacial polycondensation between diethylenetriamine and sebacoyle chloride are studied experimentally and theoretically. This planar model is developed to examine the kinetics of the reaction and to perform the estimation of parameters thanks to the experiment measurements. The effect of the operating conditions on the wall thickness is also studied. The model is shown to be consistent with the experimental data. Next, the spherical model is deduced from the first one. The results obtained with this model are in accordance with some observations of wall thickness. From this model, the increase of the wall thickness is predicted for several operating conditions. © 2006 American Institute of Chemical Engineers AIChE J, 2006 [source]

Microencapsulation of a functional dye and its UV crosslinking controlled releasing behavior

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 14 2009
Gangqiang Li
Abstract A new family of microcapsules containing photopolymerizable tripropylene glycol diacrylate (TPGDA) was synthesized by using interfacial polymerization. The release behavior of encapsulated dye could be controlled easily by changing the crosslink density of network formed from TPGDA. The chemical structure and properties of microcapsules were characterized by Fourier Transform infrared spectroscopy, scanning electron microscope, differential scanning calorimetry, optical microscope, wide angle X-ray diffraction and UV-visible spectrophotometer. The results demonstrate that the higher agitation rate results in a smaller particle size with a narrow size distribution. When core/shell ratio is low, the surface of the microcapsules becomes smooth. Additionally, it was found that UV radiation time is most effective factor to change the CC double bond conversion ratio. After microcapsules were synthesized, the release speed could be changed according to requirement by exposing them to UV light for minutes. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3630,3639, 2009 [source]

Synthesis and characterization of new polyamides based on Diphenylaminoisosorbide

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 24 2005
Asmaa A. Caouthar
Abstract New aromatic polyamides were synthesized by the microwave-assisted polycondensation of an optically active isosorbide-derived diamine with different diacyl chlorides in the presence of a small amount of N -methylpyrrolidinone. Polymers with inherent viscosities between 0.22 and 0.73 dL/g were obtained corresponding to molecular weights up to 140,000 g/mol. With interfacial polymerization or the Higashi method, lower molecular weight polymers were obtained with inherent viscosities in the range of 0.04,0.36 dL/g. Differential scanning calorimetry measurements clearly demonstrated the high thermal stability of these polymers (mp = 180,300 °C) and the absence of decomposition. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6480,6491, 2005 [source]

Synthesis of Polyanilines Bearing Optically Active Substituents

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 12 2006
Hiromasa Goto
Abstract Summary: Optically active polyanilines were prepared by an interfacial polymerization with (NH4)2S2O8 in a water/perchloric acid/chloroform system. The pristine polymer obtained in this way is in the oxidized (doped) form. The polymers display the mirror-image Cotton effect. The doping process in solution allows a change in the circular dichroism of the polymer. The procedure has great potential in the improved preparation of durable optoelectrical devices based on the good film-forming properties of chiral polymers. CD spectra of R - P2 (solid line) and S - P2 (dashed line) in 4.0,×,10,4M THF solution. [source]

Preparation of polyaniline,polypyrrole composite sub-micro fibers via interfacial polymerization

POLYMER COMPOSITES, Issue 1 2008
Shuangxi Xing
Polyaniline,polypyrrole (PANI,PPy) composite sub-micro fibers were prepared via interfacial polymerization of aniline and pyrrole using ammonium persulfate (APS) as oxidant. Carbon tetrachloride was used as the organic solvent to dissolve the monomers and APS was dissolved in HCl aqueous solution. The reaction was carried out at the interface formed by the two above solutions. Scanning electron microscopy, Fourier transformation infrared spectra and differential thermal analysis were conducted to characterize the morphology, structure and thermostability of the resulting composites. Dodecyl benzene sulfonic acid was also used as medium to make comparison with that using HCl in the reaction system. The guidance of the formation of the PANI nanofibers at the first step and the interaction between PANI and PPy were considered as the drive forces to yield the composite sub-micro fibers. POLYM. COMPOS., 29:22,26, 2008. © 2007 Society of Plastics Engineers [source]

Synthesis of exfoliated polyamide 6,6/organically modified montmorillonite nanocomposites by in situ interfacial polymerization

POLYMER COMPOSITES, Issue 6 2007
M. Tarameshlou
Polyamide 6,6 (PA 6,6)/organically modified montmorillonite (OMMT) nanocomposites were prepared by a novel method, using direct interfacial polymerization of an aqueous hexamethylene diamine and a nonaqueous adipoyl chloride in dichloromethane solution containing different amounts of OMMT dispersed nanoparticles. The state of dispersion of OMMT in the PA 6,6 matrix was investigated by means of X-ray diffraction, as well as transmission electronic microscopy. The results indicated that the OMMT nanoparticles were dispersed homogeneously and nearly exfoliated in the PA 6,6 matrix. The random arrangement of clay platelets in the PA 6,6 matrix, exfoliation, and intercalation of clays between the PA 6,6 matrix were distinguished. The amount of the incorporated OMMT in the PA 6,6 matrix was determined by means of TGA technique. Furthermore it was found that addition of a small amount of OMMT dramatically improved the thermal stability of PA 6,6. The TGA thermograms of all the synthesized nanocomposite samples showed an interesting unexpected lag in the weight loss at high temperatures, which could be another evidence for formation of fully exfoliated nanocomposites structures, with improved thermal stability. Nucleating effect of the OMMT nanoparticles and their influence on crystallization behavior of PA 6,6 was confirmed by DSC. Finally it is concluded that the in situ interfacial polycondensation is a suitable method for synthesis of nanocomposites with well dispersed structures and enhanced properties. POLYM. COMPOS., 28:733,738, 2007. © 2007 Society of Plastics Engineers [source]