The synthetic routes and materials properties of polypropylene/montmorillonite nanocomposites are reviewed. nanocomposite formation is achieved in two ways: either by using functionalized polypropylenes common organo-montmorillonites, or neat/unmodified polypropylene a semi-fluorinated organic modification for the silicates. All hybrids can be formed solventless melt-intercalation extrusion, resulting polymer/inorganic structures characterized coexistence intercalated exfoliated...

We present a new method of electrochemical polymerization poly(thiophene) using dithiophene as the starting material, from which we obtain high-quality film with sharp interband absorption edge. An in situ study spectrum during doping process has been carried out. In dilute regime, results are detailed agreement charge storage via bipolarons; weakly confined soliton pairs confinement parameter $\ensuremath{\gamma}\ensuremath{\cong}0.1\ensuremath{-}0.2$. At highest levels, data characteristic...

The results of experimental studies photoluminescence and photoconductivity in cis- trans-${(\mathrm{CH})}_{x}$ are presented. For cis-${(\mathrm{CH})}_{x}$, we find recombination luminescence the scattered light spectrum at 1.9 eV, near interband absorption edge. turns on sharply for excitation energies greater than 2.05 implying a Stokes shift 0.15 eV. Studies temperature dependence ($T>~7$ K) show no loss intensity even temperatures as high 300 K. Isomerization same sample quenches...

This paper discusses a new family of ferroelectric polymorphic fluoroterpolymers comprosed vinylidene difluoride (VDF), trifluoroethylene (TrFE), and chloro-containing third monomer, such as chlorodifluoroethylene (CDFE), chlorotrifluoroethylene (CTFE), which feature relatively narrow molecular weight composition distributions. The terpolymers were prepared by bulk reaction process with low temperature free radical initiator, i.e., the oxidation adducts trialkylborane oxygen. slightly bulky...

Detailed quantitative studies of the visible near-ir absorption spectra trans-${(\mathrm{CH})}_{x}$ have been carried out in semiconducting, transitional, and metallic regimes. With use opto-electrochemical technique to take advantage control precision electrochemical doping, data were obtained situ, during doping process. Thin ${(\mathrm{CH})}_{x}$ films polymerized on conducting glass used as one electrode an cell (${\mathrm{Li}}^{+}$Cl${\mathrm{O}}_{4}^{\ensuremath{-}}$ propylene...

The optical-absorption spectra of pure cis- and trans-polyacetylene at various hydrostatic pressures, in the region 0-13 kbar, are reported. We find a large red shift absorption edge indicating reduction energy gap ${E}_{g}$ as function increasing pressure both isomers. At 13 is reduced trans-${(\mathrm{CH})}_{x}$ by about 0.17 eV (i.e., \ensuremath{\sim} 10%). In addition, decrease peak height broadening leading interband coefficient observed high pressures. These changes result from an...

Polyolefins, including polyethylene (PE) and polypropylene (PP), represent more than half of commercial polymers produced in the world. They are known to be cost-effective good performing materials used a broad range commodity applications that influence our everyday lives. On other hand, less attention has been paid their specialty applications, commonly requiring material have multiple performance functions. The limitations shortcomings polyolefins stemmed from lack functionality structure...

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication the EditorNEXTSynthesis of Functionalized Isotactic Polypropylene Dielectrics for Electric Energy Storage ApplicationsXuepei Yuan, Yuichi Matsuyama, and T. C. Mike Chung*View Author Information Department Materials Science Engineering, The Pennsylvania State University, University Park, 16802*To whom all correspondence should be addressed. E-mail: [email protected]Cite this: Macromolecules 2010, 43, 9, 4011–4015Publication...

This paper discusses a new class of high performance polyethylene-based anion exchange membranes (PE–AEMs) that contain wide concentration range pendant (flexible) ammonium chloride (NR3+Cl–) groups and with or without cross-linked PE matrix structure. The chemistry involves metallocene-mediated polymerization ethylene, silane-protected α,ω-amino-olefin [CxN(SiMe3)2], styrenic diene (cross-linker), to form ethylene/CxN(SiMe3)2 copolymers ethylene/CxN(SiMe3)2/diene terpolymers, respectively....

Polymer dielectrics with low-loss and high-temperature tolerance are extremely desirable as electrical energy storage materials for advanced electronics power applications. They can allow fast switching rates during conversion therefore achieve high densities without thermal issues. Here, we explore polypropylene (PP), the state of art dielectric polymer, present an innovative approach to substantially improve stability concurrently reduce loss PP. In particular, cross-linkable antioxidant...

By integrating polyvinyl alcohol (PVA)-borate-tannic acid (TA)-sodium sulfate into cellulosic wood matrices, a novel wood-basedPVA-borate-TA-sodium (WPBTS) hydrogel is successfully synthesized. Through multicomponent synergistic design combining natural lignocellulose, PVA, borax, TA, and sodium sulfate, multiple dynamic cross-linking mechanisms-dynamic borate bonding, hydrogen metal-ligand interactions-are established, resulting in WPBTS hydrogels with exceptional mechanical properties...

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication the EditorNEXTExfoliated PP/Clay Nanocomposites Using Ammonium-Terminated PP as Organic Modification for MontmorilloniteZ. M. Wang, H. Nakajima, E. Manias, and T. C. ChungView Author Information Department of Materials Science Engineering, The Pennsylvania State University, University Park, 16802 Cite this: Macromolecules 2003, 36, 24, 8919–8922Publication Date (Web):October 31, 2003Publication History Received2 September...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA Novel "Stable" Radical Initiator Based on the Oxidation Adducts of Alkyl-9-BBNT. C. Chung, W. Janvikul, and H. L. LuView Author Information Department Materials Science Engineering The Pennsylvania State University Park, 16802Cite this: J. Am. Chem. Soc. 1996, 118, 3, 705–706Publication Date (Web):January 24, 1996Publication History Received14 August 1995Published online24 January 1996Published inissue 1...

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication the EditorNEXTStudy of VDF/TrFE/CTFE Terpolymers for High Pulsed Capacitor with Energy Density and Low LossZhicheng Zhang T. C. Mike ChungView Author Information Department Materials Science Engineering, The Pennsylvania State University, University Park, 16802 Cite this: Macromolecules 2007, 40, 4, 783–785Publication Date (Web):January 17, 2007Publication History Received25 November 2006Revised5 January 2007Published...

This paper systematically examines the family of poly(vinylidene difluoride) (PVDF)-based fluoropolymers, including homo-, co-, and terpolymers containing vinylidene fluoride (VDF), trifluorethylene (TrFE), chlorotrifluoroethylene (CTFE) units, with objective tuning polymer chain conformation crystal structure in order to identify most suitable for energy storage (capacitor) applications. All polymers have high molecular weight, uniform composition distribution, semicrystallinity, purity....

Long chain branched isotactic polypropylenes (LCBPP) prepared via the combination of rac-Me2Si(2-Me-4-Ph-Ind)ZrCl2/MAO catalyst and a p-(3-butenyl)styrene (T-reagent) were characterized to investigate their synthesis, structure, solution properties, melt properties. The T-reagent, in presence hydrogen, simultaneously served as comonomer transfer agent, resulting LCBPP with high molecular weight, desirable branch point density, relatively well-defined structure. Additionally, metallocene...

A series of poly(vinylidene fluoride)-g-sulfonated polystyrene (PVDF-g-SPS) graft copolymers were systematically synthesized and examined with the focus understanding how polymer microstructure (backbone molecular weight, density, length, sulfonic acid concentration, ion exchange capacity, etc.) affects their morphology, water uptake, proton conductivity under various environmental conditions (temperature relative humidity). The synthesis these relatively well-defined structures involves...

This paper discusses a new synthesis route to prepare microporous boron substituted carbon (B/C) materials that show significantly higher hydrogen binding energy and physisorption capacity, compared with the corresponding carbonaceous (C) materials. The chemistry involves pyrolysis of designed boron-containing polymeric precursors, which are polyaddition polycondensation adducts between BCl3 phenylene diacetylene lithiated diacetylene, respectively. During pyrolysis, most moieties were...

This paper discusses a novel approach that may provide complete solution to combating oil spills. The technology is centered on cross-linked polyolefin terpolymer (x–OS–DVB), containing 1-octene, styrene, and divinylbenzene units, which an superabsorbent polymer (oil–SAP) with aliphatic aromatic side chains have similar solubility parameters (oleophilic hydrophobic properties), the hydrocarbons in crude oil. Some x–OS–DVB terpolymers, desirable morphology (amorphous, low Tg, high free...

Despite the commercial importance of maleic anhydride grafted polypropylene (PP-g-MAH), it has long been a scientific challenge to prepare this polymer with well-controlled molecular structure. This paper discusses new chemical route that can form PP-g-MAH desirable MAH content, single incorporated unit, white color, high weight, and narrow weight composition distributions. The chemistry involves unique PP-co-p-BT copolymer as "reactive intermediate" be effectively prepared by...

This paper discusses a new family of polymeric stabilizers (antioxidants) containing polypropylene backbone and several pendant hindered phenol groups (PP-HP), with both random tapered copolymer microstructures. They are effectively prepared by Steglich esterification the corresponding hydroxylated (PP-OH) copolymers molecule carboxylic acid moiety. Some resulting PP-HP show significantly higher thermal-oxidative stability than pristine PP polymer commercial products that contain small...