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Concerned about environmental pollution, and aware of the comfort that polyethylene provides for daily human life, this work sought to replace a percentage of high-density polyethylene (HDPE) with human or bovine hair. Hair is natural, abundant, light weight, non-toxic, and disposed of as garbage. The main disadvantage of natural composites is the interfacial adhesion. To increase the interfacial adhesion between hair and HDPE, stearic acid or oleic acid was chemically anchored on the hair surface, which leads to an improved contact angle hysteresis and hydrophobicity. Dynamic-mechanical properties of the composites were investigated focusing on the type of carboxylic acid used (stearic or oleic acid), hair length, hair type (human or bovine) and amount of hair used in the composite. Taking 40[degrees]C as a reference, using 15% of hair with a length of 1 [+ or -] 0.15 mm, the highest storage modulus value was obtained with HDPE with human hair modified with oleic acid, exceeding the value of the storage modulus of HDPE by 67.64%. Increasing storage modulus on composites indicates of interfacial interaction and chemical affinity improvement between hair and polyethylene. KEYWORDS bovine hair, carboxylic acids, composites, human hair, polyethylene, storage and loss modulus, 1 | INTRODUCTION Plastics are probably the most versatile materials we know, the demand for plastic raw materials is enormous, and the global production of plastics has increased from 2 [...]

Poly(ethylene oxide) (PEO) based polyurethaneurea-silica nanocomposites were prepared by solution blending and characterized by Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Differential Scanning Calorimetry and tensile testing. The colloidal silica nanoparticles with an average size of 50 nm were synthesized by modified Stober method in isopropanol. Silica particles were incorporated into three cycloaliphatic polyurethaneurea (PUs) copolymers based on PEO oligomers with molecular weights of 2,000, 4,600, and 8,000 g/mol. Hard segment content of PUs was constant at 30% by weight. Silica content of the PU nanocomposites varied between 1 and 20% by weight. Soft segment (SS) glass transition and melting temperatures slightly increased with increasing filler content for all the copolymers. Degree of SS crystallinity first increased with 1% silica incorporation and subsequently decreased by further silica addition. Elastic modulus and tensile strengths of PU copolymers gradually increased with increasing amount of the silica filler. Elongation at break values gradually decreased in PEO-2000 based PU copolymer with increasing silica content, whereas no significant change was observed in PUs based on PEO-4600 and PEO-8000. Enhancement in tensile properties of the materials was mainly attributed to the homogeneous distribution of silica filler in polymer matrices and strong polymer-filler interactions., INTRODUCTION Polymeric nanocomposites have been a focus of attention particularly because of their enhanced physicochemical, thermal, mechanical, and other engineering properties, enabling their use in a wide range of applications, [...]

The production of polymers from renewable materials has arisen increasing interest because of the environmental impacts caused by conventional processes. In this context, the present manuscript investigates the step-growth polymerization [...]

The clarifying effect of using bis-oxalamide compounds on linear low density polyethylene (LLDPE) has been investigated for the first time. It was demonstrated that the haze of a commercial LLDPE resin, DOWLEX[TM] 2045G, can be reduced up to 50% by adding 0.2 wt % of a bis-oxalamide clarifying agent. The investigations on the crystalline morphology revealed that the density of spherulite cores increased with increasing concentration of bis-oxalamide N5. Through an investigation of structure-property relationships based on the tunable bisoxalamide structure, it was demonstrated that the combination of linear alkyl core and cyclohexyl pendant groups showed the best clarification. The interactions of clarifying molecules were simulated using dynamic molecular simulation. The simulation suggested that the rigidity of the core functionality played a role on the hydrogen bonding in the intermolecular network, which may contribute to the macroscopic clarification performance., INTRODUCTION Semicrystalline polymers, such as polypropylene (PP) and polyethylene (PE), are naturally translucent or opaque, because crystals aggregate into large complexes known as spherulites [1-4]. The size of these spherulites [...]

Polytetrafluoroethylene (PTFE) composite coatings doped with copper acetate and polyethylene (PE) were fabricated on rubber substrate by electron beam dispersion technique. The effects of dopant nature and glow discharge treatment on morphology, structural and tribological properties of the coatings were investigated. The results showed that Cu and PE doping change the surface structure of PTFE-based composite coatings due to the chemical reactions between the dispersion products. Cu-PEPTFE coatings show the columnar and layered growth models without and with discharge treatment. Cu adding decreases the crystallinity, branched degree and unsaturated degree of PE coatings, but increases the branched degree and unsaturated bonds in the PE-PTFE coatings. Glow discharge enhances the crystallinity and ordering degree of composite coatings. Friction experiments indicated the significant difference of composite coatings in the nature of their destruction during friction. PE-PTFE coating is characterized of the brittle fracture with clear failure boundaries but Cu-PE-PTFE coating shows a rough surface without cracking and delaminating after friction. Cu doping increases the dynamic coefficient of friction of PE and PE-PTFE composite coatings, but discharge plasma decreases the dynamic coefficient of friction. Cu-PEPTFE composite coating after discharge treatment has the decreased dynamic coefficient of friction and improved wear resistance., INTRODUCTION Polymer based materials have been widely used under the condition of dynamic sliding state to replace metal or ceramics parts, like the sealing element of rotary shaft and other [...]

We investigate the influence of several bifunctional phenol additives (resorcinol: RES, hydroquinone: HYD, p-hydroxybenzoic acid: PHBA, and p-nitrophenol: PNP) on the crystallization of matrix polymer, polyethyleneoxide. We employ solid state Nuclear Magnetic Resonance spectroscopy (NMR), Differential Scanning Calorimetry (DSC), optical microscopy, and Small Angle X-ray Scattering (SAXS) to investigate crystallization of the additivated PEO and compare with Density Functional Theory (DFT) calculations of additive-PEO interactions. Additivepolymer interactions are a function of the functional groups on the additive. Temperature-dependent spherulitic growth rate measurements from optical microscopy and SAXS lamellar long spacings indicate a distinct trend in the effect of additives on PEO crystallization. Change in PEO crystallization is most pronounced with PNP, followed by PHBA and finally RES and HYD. This trend correlates qualitatively with the binding energies of additive-PEO interactions from DFT studies. Our results suggest that DFT calculations might be a useful screening tool to evaluate the influence of additives on polymer crystallization. POLYM. ENG. SCI., 57:857-864, 2017. [c] 2016 Society of Plastics Engineers, INTRODUCTION Commercially available polymers typically contain an additive package that includes antioxidants, stabilizers, etc. The use of additives to control the crystallization of semicrystalline polymers is commonly practiced in industry. [...]

The effect of nanoclay on the plane-strain fracture behavior of pristine High density polyethylene (HDPE) and recycled HDPE blends was studied using the essential work of fracture (EWF) concept. The failure mode of EWF tested specimens was found to be associated with the specific non-EWF ([β.sub.B][w.sub.p,B]). Adding 6-wt% of nanoclay to pristine HDPE and 2-wt% to recycle-blends greatly decreased the [β.sub.B][w.sub.p,B] values and led to a transition from ductile to brittle failure mode. A fractographic study revealed that the difference in failure modes was caused by the changes in micro and macro morphologies, which could be related with the specific EWF ([w.sub.e,B]). In the ductile failure, [w.sub.e,B] is governed by the fibril size; adding nanoclay and recycled HDPE to pristine HDPE decreased the fibril size and subsequently lowered the we B value. In the brittle failure, the we S value was enhanced by creating a rough fracture surface. Adding nanoclay to pristine HDPE, a steadily decrease in [w.sub.e,B] was measured until 4-wt% after which the change was insignificant. Conversely, nanoclay content more than 2-wt% in recycle-blends greatly decreased the [w.sub.e,B] value. A transition map was constructed to illustrate the potential failure mode and the associated fracture morphology based on the tested material compositions. POLYM. ENG. SCI., 56:222-232, 2016. [C] 2015 Society of Plastics Engineers, INTRODUCTION High density polyethylene (HDPE) is one of the most widely used engineering plastics. With good mechanical properties, corrosion resistance, low cost, and ease of processing, the use of HDPE [...]

Nanoparticles with engineered surface chemistry represent novel means in controlling the in-situ formation of property-specific supramolecular structure in advanced processing technologies of semicrystalline polymers. Often, the published experimental data on effects of interfacial adhesion on the crystallization kinetics of polymer nanocomposites report contradictory results even for similar systems. Computer simulations allow separating structural and test variables, thus, can provide useful framework for understanding these apparent controversies. Our MD simulation of Regime II crystallization showed that adding non-nucleating spherical nanoparticles reduced the crystal growth rate, [G.sub.II] compared with the neat polymer with the extent of the reduction proportional to the strength of interfacial attraction. It also suggested that, regardless of the strength of the interfacial interactions, additional reduction of the [G.sub.II] was caused by topological constraints imposed by nanoparticles on the stem attachment. Both the Lauritzen-Hoffman model predicted and MD simulated [G.sub.II] reduction agreed fairly well with that obtained experimentally for monodisperse PE filled with nanometer-sized Si[O.sub.2]. POLYM. ENG. SCI., 53:2696-2704, 2013. © 2013 Society of Plastics Engineers, INTRODUCTION Polymer crystallization is kinetically controlled under conditions far from thermodynamic equilibrium involving molecular motions on various length and time scales. Many plastics processing technologies utilize this feature of plastics [...]

Poly(ethylene oxide)/silica (PEO/Si[0.sub.2]) nanocomposite films were modified, and nanocomposite gels were prepared by γ-irradiation up to 100 kGy. Thermal analysis, optical microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy revealed that the outcome mostly depended on the state of the PEO matrix on irradiation and that the state of the sample had a bearing on the effect of nanosilica addition. In unirradiated films, nanosilica induced heterogenous nucleation and increased crystallization temperatures proportional to its content. On irradiation of nanocomposite films, degradation prevailed, resulting in an increased crystallinity of samples irradiated to 50 kGy and a significant deterioration of mechanical properties at higher doses. In films irradiated in air, nanosilica did not provide radiation resistance. It enhanced oxidative degradation by increasing the content of a more radiation sensitive amorphous phase and probably facilitated the crystallization of broken chains resulting in an additional crystallinity increase. In the same dose range, the irradiation of PEO/nano-Si[0.sub.2] aqueous solutions produced cross-linked nanocomposite gels of much lower crystallinity and phase transformation temperatures and better mechanical properties. Interactions and radiation-induced effects in nanosilica likely contributed to a further crystallinity reduction in nanocomposite gels. Pronounced changes on the addition of 20 wt% of nano-Si[0.sub.2] to both nanocomposite films and gels indicate a possible synergism of γ-irradiation and nanoparticle addition. POLYM. ENG. SCI., 53:2318-2327, 2013. © 2013 Society of Plastics Engineers, INTRODUCTION Poly(ethylene oxide) (PEO) is a semicrystalline polymer with numerous applications (hydrogels for active substance release, polyelectrolytes, etc.). Among other characteristics, the degree of PEO crystallinity greatly influences its properties [...]

The influences of the dispersion level of carbon nanotubes (CNTs) and functionalized CNTs on the transmittance properties of ultrahigh-molecular weight polyethylene (UHMWPE) gel solutions and on ultradrawing properties of their asprepared fibers are reported. The transmittance properties suggest that the dispersion level of functionalized CNTs in UHMWPE/functionalized CNTs gel solution is significantly better than plain CNTs in UHMWPE/CNTs gel solutions. The orientationfactors, achievable draw ratios, tensile strength), and modulus (E) values of UHMWPE/CNTs ([f.sub.x][c.sub.y]) and UHMWPE/functionalized CNTs ([f.sub.x][c.sub.f-y]) as-prepared fiber specimens reached a maximum value as their CNT and functionalized CNT contents approached optimum contents at 0.00015 and 0.0001 wt%, respectively. The of and E values of both [f.sub.x][c.sub.0.0012] and [f.sub.x][c.sub.f-0.001] series fiber specimens prepared at their optimum CNT and functionalized CNT contents reached another maximum as their UHMWPE approached optimum UHMWPE concentration of 1.7 wt%. Possibie reasons accounting for these interesting properties are proposed. POLYM. ENG. SCI, 51:2552-2563, 2011. © 2011 Society of Plastics Engineers, INTRODUCTION In recent years, the DSM Corp. (Holland) produced ultrahighmolecular weight polyolefin material through gel spinning and applied for a patent; it attracted great interest from related companies and research [...]

Aminoglycolysis and simultaneous hydrolysis-aminoglycolysis of poly(ethylene terephthalate) (PET) wastes by diethanolamine (DEA) was attempted in the presence of xylene, with the aim of obtaining intermediates containing both hydroxyl and carboxyl end groups, which could be employed in polyurethane surface coatings. Aminoglycolysis and simultaneous hydrolysis-aminoglycolysis reactions were carried out with the catalysis of zinc acetate (ZnAc) at high temperatures and relatively high pressures. Depolymerization products were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimeter (DSC). To prepare polyurethane surface coating films, the depolymerization products were reacted with 1,4 butanediol (BDO) and toluene diisocyanate (TDI) in the presence of dibutiltin dilaurate (DBTDL) catalyst and pyrogallol inhibitor. After the films prepared, the physical properties such as hardness, drying degree, adhesion, and impact resistance of these films were investigated. The intermediates yielded from medium to very hard coatings with excellent adhesion and having medium to very good drying degree. POLYM. ENG. SCI., 51:746-754, 2011. © 2011 Society of Plastics Engineers, INTRODUCTION The chemical recycling of poly(ethylene terephthalate) (PET) is carried out with the aim of obtaining either its monomers such as terephthalic acid (TPA), ethylene glycol (EG), and bis(2-hydroxyethyl terephthalate) [...]

Systemic investigation of the influence of the plain and functionalized carbon nanotube (CNT) contents on the ultradrawing properties of ultrahigh molecular weight polyethylene/carbon nanotubes (UHMWPE/CNTs, [FC.sub.y]) and UHMWPE/functionalized CNTs ([FC.sub.fx-y]) as-prepared fibers are reported. In a way similar to those found for the orientation factor values, the achievable draw ratios ([D.sub.ra]) of the [FC.sub.y] and [FC.sub.fx-y] as-prepared fibers approached a maximum value as their CNT and/or functionalized CNT contents reached their corresponding optimum values. The maximum [D.sub.ra] values obtained for [FC.sub.fx-0.001] as-prepared fiber specimens prepared at varying maleic anhydride grafted polyethylene ([PE.sub.-g-MAH])/modified CNTs weight ratios were significantly higher that of the [FC.sub.0.0015] as-prepared fiber specimen prepared at the optimum plain CNT content. Tensile property analysis further suggested that excellent orientation and tensile properties of the drawn [FC.sub.y] and [FC.sub.fx-y] fibers can be obtained by ultradrawing the fibers prepared at their optimum plain CNT and/or functionalized CNT contents. To understand the interesting orientation, ultradrawing and tensile properties of [FC.sub.y] and [FC.sub.fx-y] fiber specimens, FTIR, specific surface area, and SEM morphology analysis of the plain and functionalized CNTs were performed in this study. POLYM. ENG. SCI., 51:687-696, 2011. [C] 2010 Society of Plastics Engineers, INTRODUCTION Carbon nanotubes (CNTs) are long and slender fibers where the walls of the tubes are hexagonal carbon (graphite structure) and often capped at each end [1]. They attracted great [...]

Camic, CL, Hendrix, CR, Housh, T J, Zuniga, JM, Mielke, M, Johnson, GO, Schmidt, R J, and Housh, DJ. The effects of polyethylene glycosylated creatine supplementation on muscular strength and power. J Strength Cond Res 24(12): 3343-3351, 2010-The purpose of the present investigation was to examine the effects of 28 days of polyethylene glycosylated creatine (PEG-creatine) supplementation on 1-repetition maximum bench press (1RMBp) and leg extension (1RMLE), mean power (MP), and peak power (PP) from the Wingate Anaerobic test and body weight (BW). This study used a randomized, double-blind, placebo-controlled, parallel design. Twenty-two untrained men (mean age [+ or -] SD = 22.1 [+ or -] 2.1 years) were randomly assigned to either a Creatine (n = 10) or Placebo (n = 12) group. The Creatine group ingested PEG-creatine (5 [g*d.sub.-1]), whereas the Placebo group ingested maltodextrin powder (5 [g*d.sub.-1]). All subjects performed bench press and bilateral leg extension exercises to determine their 1RM values, and 2 consecutive Wingate Anaerobic Tests (separated by 7 minutes) on a cycle ergometer to determine MP and PP before supplementation (day 0) and after 7 (day 7) and 28 (day 28) days of supplementation. The results indicated that there was a significant (p < 0.05) increase in 1R[M.sub.BP] between days 0 and 28 for the Creatine group but not for the Placebo group. There were no significant changes, however, in 1R[M.sub.LE], MP, PP, or BW for the Creatine or Placebo group. These findings indicated that 28 days of PEG-creatine supplementation without resistance training increased upper body strength but not lower body strength or muscular power. These findings supported the use of the PEG-creatine supplement for increasing 1R[M.sub.BP] strength in untrained individuals. KEY WORDS PEG, 1 repetition maximum, supplements, bench press, leg extension

As a new grade of polyethylene materials with unique chain architectures, hyperbranched polyethylenes synthesized by chain walking ethylene polymerization have great potential for industrial application as novel viscosity index (VI) improver in lubricant formulation. Although high-molecular-weight hyperbranched polyethylenes (weight-average molecular weight of about [10.sup.5] g/mol) possess high shear stability, their viscosity thickening properties are compromised due to their compact chain architectures. In this work, we aim at improving their viscosity thickening property by increasing polymer molecular weight. A range of hyperbranched polymers of various enhanced molecular weights were synthesized by chain walking ethylene polymerization in the presence of small amounts of 1,4-butanediol diacrylate as a difunctional crosslinker. The molecular weight dependences of viscosity thickening power and shear stability of these polymers containing crosslinking structures were evaluated. It is found that, with the increase of molecular weight via crosslinking, these polymers showed consistently enhanced viscosity thickening power, but with the reduced shear stability. However, their shear stability was still significantly better compared to linear polymers. POLYM. ENG. SCI., 50:911-918, 2010. [C] 2009 Society of Plastics Engineers, INTRODUCTION Viscosity index (VI) is an important parameter that evaluates the dependence of lubricant viscosity on temperature. It defines the quality and application temperature range of lubricants. Lubricants of high [...]

The main objective of this research is to investigate the potential use of pyrolisis low density polyethylene (LDPE) as a modifier in hot mix asphalt paving mixtures. Five different blends including conventional mix were subjected to binder testing such as rheological tests, as well as to some other tests related to the homogeneity of the system. Optimum asphalt content was obtained by Marshall method and used in all the modified mixes. The engineering properties, including Marshall stability, indirect tensile strength, and compressive strength were determined. Research results indicate that modified binders showed higher softening point, keeping the values of ductility at minimum range of specification of ([100.sup.+] cm), and caused a reduction in percentage loss of weight due to heat and air (i.e., increase durability of original asphalt). The results indicated that the inclusion of pyrolisis LDPE with asphalt concrete mixtures gave a quite satisfactory result in terms of stability and other Marshall properties, increase in indirect tensile, and compressive strength. DOI: 10.1061/(ASCE)0899-1561 (2009)21:10(618) CE Database subject headings: Polyethylene; Asphalts; Rheology; Tensile strength; Compressive strength; Concrete.

The present theoretical study explores the interaction of various energetic molecular projectiles and clusters with a model polymeric surface, with direct implications for surface analysis by mass spectrometry. The projectile sizes (up to 23 kDa) are intermediate between the polyatomic ions (S[F.sub.5], [C.sub.60]) used in secondary ion mass spectrometry and the large organic microdroplets generated, for example, in desorpfion electrospray ionization. The target is a model of amorphous polyethylene, already used in a previous study [Delcorte, A.; Garrison, B. J. J. Phys. Chem. C 2007, 111, 15312]. The chosen method relies on classical molecular dynamics (MD) simulations, using a coarsegrained description of polymeric samples for high energy or long time calculations (20-50 ps) and a full atomistic description for low energy or short time calculations (

Space charge behavior at physical interfaces in cross-linked polyethylene (XLPE) films subjected to a dc field has been investigated as a function of the nature of the interfaces using the pulsed electro-acoustic technique. Aluminum, gold and carbon black-loaded polyethylene were used as electrodes to investigate space charge build-up in a single dielectric layer. A sandwich structure constituted by two dielectric films of the same nature was used to study the charging propensity of the dielectric/dielectric interface. Samples with uncharged and charged interfaces were investigated. The time dependence of the space charge distribution was subsequently recorded at different temperatures under field (polarization) and short circuit conditions (depolarization). Charge injection rather than ionic species migration is seen to control space charge distribution in single and double- layer samples in agreement with the storage conditions of the XLPE films. It is shown that the sign and distribution of the space charge depend drastically on the nature and the polarity of the electrodes and that dielectric/dielectric interfaces behave differently depending on the sign of the charge, providing deeper traps for positive charge carriers. Index Terms--Space charge, dielectric interface, pulsed electro acoustic technique.

This research investigated the enhancement of polyethylene properties through the use of additives to make it suitable as a roofing material. To function as a roofing material, weatherability (resistance to photo-oxidation), low flammability, and good strength were identified as the key requirements that must be met by the polymer. The additives: carbon black, clay, and ammonium chloride were compounded with the polyethylene. Carbon black was used to protect against photo-oxidation; ammonium chloride was used as a flame retardant, and clay served as a flame retardant while also imparting hardness. ASTM D638-46T tensile test pieces were used to determine the strength of the mixtures, the horizontal UL 94 incipient regime flame test was used to determine flammability, and a simulated weathering test was developed to evaluate weatherability. Results indicated that at about 8.96% clay and 17.42% ammonium chloride, the polyethylene matrix has an average strength of 3.04 [+ or -] 0.42 MPa. The horizontal UL 94 fire test showed a marked improvement of flammability properties over that observed for virgin polyethylene. The simulated weathering test also showed an improvement in weatherability properties in polyethylene containing the additives. DOI: 10.1061/(ASCE)0899-1561 (2008)20:8(516) CE Database subject headings: Polyethylene; Roofs; Ultraviolet radiation; Construction materials.

The systematic derivatization of polyethylene imine (PEI) with alkyl ([C.sub.2]-[C.sub.12]), benzyl, and guanidinium groups which gives rise to catalysts ('synzymes') with rate accelerations of up to [10.sup.4] for the intramolecular transesterification of 2-hydroxypropyl-p-nitrophenyl phosphate, HPNP, in the absence of metal is reported.

The experimental and theoretical studies were conducted to determine the effects of the sample size on the chemical and physical properties of copper plasma-implanted polyethylene. The nonuniform metal implantation are attributed to laterally different surface potential on the insulating materials due to surface charge buildup and more effective charge transfer near the edge of the sample.

This paper deals with the viability of using reclaimed polyethylene (PE) derived from low-density PE carry bags collected from domestic waste as an additive in asphalt concrete mixtures. Different ratios of PE (2.5, 5.0, 7.5, and 10% by weight of asphalt) were blended with (80/100)-paving grade asphalt. The dynamic creep test (unconfined), indirect tensile test, resilient modulus test, and Hamburg wheel track tests were carried out on asphalt concrete mixtures blended with PE. The analyses of test results show that the performance of PE-modified asphalt mixtures are better when compared to conventional mixtures. The rutting potential and temperature susceptibility can be reduced by the inclusion of PE in tile asphalt mixture. APE content of 5% by weight of asphalt is recommended for the improvement of the performance of asphalt concrete mixtures similar to that investigated in this study. DOI: 10.1061/(ASCE)0899-1561(2007)19:6(500) CE Database subject headings: Asphalt concrete; Tensile strength; Polyethylene; Mixtures.

New insights into the mechanism of various triplet radical-pair combinations are provided, where in the persistent radical effect play an extremely important role in the distinction between the in-cage and out-of-cage processes. The results clearly indicate that the decarbonylation rates in such combinations are not dependent on its microviscosity.

The influence of two diblock copolymers, each comprising a nonionic poly(ethylene oxide) block and an anionic block comprising pendent aromatic sulfonate groups on the precipitation of calcium carbonate is compared. It is observed that a poly(ethylene oxide) diblock copolymer is particularly versatile in causing morphological changes in calcite particles.

The vibrational sum frequency generation (SFG) spectroscopy is employed to investigate and explore the phase transitions of several phospholipid monolayers containing poly(ethylene oxide) lipids at the air-water interface. The results indicate that the mixed monolayers exist in pancake, mushroom or the brush state, wherein the mushroom-brush transition accompanies the conversion of the alkyl group from an irregular structure to the all-trans structure.

Transmission electron microscopy (TEM), particle size analyzer (PSA), Fourier transformed infrared and fluorescence spectroscopy are used to investigate the acid effect on the aggregation of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymers E[O.sub.20]P[O.sub.70]E[O.sub.20]. It is attributed to the aggregation of micelles through the protonated water bridges between different micelles through hydrogen bonds.

The diffusion of the radioisotope [super 86]Rb in an amorphous polymer-salt complex consisting of poly(ethylene oxide) and sodium iodide is found to be faster at all temperatures investigated than tracer self-diffusion of the smaller alkali metal cation [super 22]Na. The faster overall transport of Rb as measured by radiotracer diffusion is due to a relatively large fraction of RbI pairs, in conjunction with the finding that the ion pair diffusivities exceed the single carbon diffusivities by 2 orders of magnitude.

A model system, polyethylene (PE) in biphenyl is simulated, to gain the insight into the detailed solvation structures and the molecular mechanism of polymer chain solvation. Using atomistic molecular dynamics (MD) simulation, it is found that when the biphenyl is far from PE chain or in the bulk, the dihedral angle of the two rings in the solvent molecule are 32 degree.

The nanosheet polyethylene (PE) is prepared with silica-supported metallocene catalyst and the effect of the polymerization conditions on the morphology of the resultant PE is investigated. The silica is found to break up into sheet fragments instantaneously during polymerization, whereas the polyethylene could replicate it to obtain nanosheet polyethylene, and a possible formation mechanism of the nanosheet polyethylene is proposed.

The crystalline microdomains of a poly(ethylene oxide) (PEO)-lithium triflate sample with an oxygen/lithium ratio of 20:1 is characterized using solid-state NMR data collected with the rotational-echo double-resonance (super 13)C{(super 7)Li} (REDOR) pulse sequence. The results have shown that the lithium crystalline microdomains are nearly identical to those of a completely crystalline 3:1 sample, for which the crystal structure is known.

Potential-modulated spectroelectrochemical ATR (PM-ATR) instrument is applied using multiple internal reflections at an optically transparent electrode to analyze the charge-transfer kinetics and electrochromic response of adsorbed films. This method is used to investigate the high-speed limit of electrochromic switching in poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-ethylenedioxythiophene methanol) (PEDTM) polymer and copolymer films.

A new unique method is represented for periodically patterning of polymeric materials on individual one dimensional (1-D) carbon nanotubes (CNTs) by using a controlled polymer crystallization method. The method provides an opportunity for CNT separation, as nano-hybrid shish-kebab (NHSK) formation conditions depend on the CNT structures and hence also opens a new pathway for patterning polymers in an ordered and controlled manner.

A description is presented on fabrication of 2D arrays of Au nanorods using nanoporous anodized aluminum oxide (AAO) templates coated with polyethylenimine (PEI), with very fine control over nanorod height. Uniform growth rate is determined by the adsorbed PEI matrix, which controls the growth kinetics of the grains comprising the nanorods.

It is believed that space charge build-up in cross-linked polyethylene (XLPE) insulation is the main cause of premature failure of underground power cables. The space charge activities in XLPE depend on many factors such as additives, material treatment, ambient temperature, insulator/electrode interface, etc. Degassing is the process of subjecting the XLPE to a moderately high temperature, thereby removing volatile residual by-products and additives that are commonly employed in cable manufacturing to improve insulation performance. While there have been reports comparing space charge activities (as-received) un-degassed and degassed samples, little attention has been placed on degassing conditions effect on space charge. In this paper, investigations of morphology and space charge distribution of planar XLPE samples was carried out as parameters such as degassing temperature, degassing duration and sample thickness were adjusted. Changes in the morphological structure of the material were probed with the differential scanning calorimeter and the transmission electron microscopy, whereas space charge distribution of the samples subjected to dc electric stress was monitored for 24 h using the laser induced pressure pulsed technique. It was revealed that degassing temperature, duration and the thickness of the degassed sample has a direct effect on the morphological structure and space charge distributions of the samples. It is believed that the presence and amount of by-products takes precedence over the morphology of the material as far as space charge evolution is concerned. Index Terms--XLPE cable insulation, degassing treatment, space charge, morphological feature, by-products ionisation, charge injection.

The development of (4-dialkylamino-2,6-pyridylene)ethynylene polymer 2, saccharide binding of which is regulated by H(super +)-induced stabilization of the helical conformation is reported. The analysis shows that the pyridium-pyridine dimeric structure prefers its cisoid conformation to its transoid one.

The statistics of knots with numerical simulations of a simplified model of polyethylene is examined. A typical size with individual knots, which are found to be small, can be associated in the swollen phase but large (loose and spread out) in the dense phases.

The structural changes of the crystalline lamellae and lamellar superstructures and the single chain radius of gyration of cold-drawn polyethylene, after annealing, is studied by means of combined small- and wide angle X-ray scattering and small-angle neutron scattering (SANS). It is observed that the global anisotropic shape of the chains is preserved even after prolonged annealing, and that the mobility of polyethylene chains is a local phenomenon.

Potentiometric titration and eletrophoretic mobility measurements are used to investigate the solvent isotope effects on the interaction between the hyperbranched cationic polyelectrolyte, polyethylene, imine (PEI), and the anionic surfactant sodium dodecyl sulfate (SDS). A significantly higher fraction of the amine groups is found to be protonated when the PEI is dissolved in D2O compared to H2O at the same pH/pD.

A new mass spectrometric method has been developed for the analysis of low molecular weight polyethylene (PE). Laser-induced acoustic desorptlon (LIAD), combined with chemical ionization by the cyclopentadienyl cobalt radical cation (CpC[o.sup.*+]) in a Fourier transform ion cyclotron resonance mass spectrometer, produces predominantly a quasimolecular ion, [(R + CpCo 2[H.sub.2]).sup.*+], for each PE oligomer (R). An examination of artificial alkane mixtures revealed no mass bias for alkanes of differing molecular weights. However, the success of the LIAD/CpC[o.sup.*+] CI technique depends greatly upon the LIAD sample preparation method used. Several sample preparation methods were evaluated, and pneumatically assisted spin coating was concluded to provide the best mass spectra as a result of its ability to provide uniform PE coverage on the LIAD foils. The molecular weight distributions measured for several low molecular weight PE samples (200-655) were found to be in good agreement with manufacturers' values as determined by gel permeation chromatography.

An investigation on the primary and secondary phosphines as chain-transfer agents for organolanthanide-mediated olefin polymerization is conducted. It is shown that organolanthanide-mediated ethylene polymerizations in the presence of a single phosphine chain-transfer agent, diphenylphosphine, yielded diphenylphosphine-capped polyethylenes.

The atomistically detailed realistic polymer models treated within the well-known density functional theory (DFT) approach to study the properties of polymers near surfaces are demonstrated. It is concluded that the theory generally performs best when the wall-polymer interaction strength is comparable to polymer-polymer interactions.

The main objective of this study was to investigate the barrier properties of polyethylene (PE), PE/modified polyamide (MPA), and PE/blends of modified polyamide and ethylene vinyl alcohol (MPAEVOH) bottles against white spirit permeation. After MPAEVOH barrier resins were blended with PE, the resistance of the PE/MPAEVOH bottles against white spirit permeation was significantly improved compared to the PE bottle. Surprisingly, with proper compositions of MPAEVOH resins, the white spirit permeation resistance of PE/MPAEVOH bottles at 40[degrees]C improved by more than 3000 times compared to the PE bottle, wherein the best permeation resistance (4200 times barrier improvement) of the PE/MPAEVOH bottles was found as the weight ratio of MPA: EVOH reached 4:1. These interesting permeation properties of PE/MPAEVOH bottles were investigated in terms of the barrier and free-volume properties of the base resins and their corresponding morphologies in blow-molded bottles. POLYM. ENG. SCI., 45:25-32, 2005. [c] 2004 Society of Plastics Engineers, INTRODUCTION It is well known that many hydrocarbon solvents (e.g., xylene, toluene, white spirit, etc.) are commonly available products that easily permeate polyethylene (PE) containers. Such permeation results in pollution, [...]

The electrical mobility of mass-selected single poly(ethylene glycol) (PEG) chains reveals a near-spherical shape above a critical mass m(super *)(z)~z(super 2). Other nonspherical shape families with structures independent of charge, and with charge-dependent stability domains, are observed.

The bis (imino) pyridine iron complex, [{2,6-(MeC=N-2,6-Pr2C6H3)2C5H3N}FeCl2], in combination with MAO and ZnEt2(> 500 equiv), is shown to catalyze polyethylene chain growth on zinc. The catalyzed chain growth process is characterized by an exceptionally fast and reversible exchange of the growing polymer chains between the iron and zinc centers.

The process of degradation of polyethylene caused by vacuum ultraviolet radiation emitted from a synchrotron is studied using vibrational spectroscopy and UV. It is indicated that analysis show the degraded polymer to have double bonded and cross linked structures.

A methodology is proposed to obtain molecular interpretation and quantitative analysis on photooxidation of polyolefins. This methodology will be useful to gather more information in the fields of polymer science.