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The effect of three different organomodified nanoclays (Cloisite 20A, Cloisite 30B, and Nanomer I28E) as well as the effect of a compatibilizer (PEgMA) was studied, with the purpose of developing greenhouse cover films based on polyethylene/ethylene vinyl acetate blends. Three organomodified clays were analyzed. The influence of organomodifier clay on film optical, morphology, mechanical, and photo-oxidative degradation properties as well as the effect of incorporation of maleic anhydride-grafted polyethylene as a compatibilizer was studied. The combined effect of these nanoclays with two different UV-oxidative protection systems for polyethylene/ethylene vinyl acetate-nanostructured films was evaluated. Two types of UV stabilizer combination systems were studied; one with a combination of heat and light stabilizers of mixture of antioxidants (phenolic and metal deactivator, Irgatec NC66) with hindered amines, Tinuvin 494AR (designated as system-A) and other with a combination of metal deactivator antioxidant, Irganox MD1024 with hindered amines Tinuvin NOR 371 and benzophenones, Chimasorb 81 (designated as system-B). A strong influence is observed in the use of compatibilizing agent, type, and content of nanoclay in the degree of dispersion as well as in the photo-oxidation behavior. The structure obtained is very dependent on the modified clay used; mostly, intercalated-exfoliated clay structure is produced. The induction period for the photodegradation reaction to start is shorter in the samples with the nanoclay than in the pure polymer. There was a difference in the effectiveness of two stabilizing systems used. It was found a better performance for the stabilizer system-A, regardless of the type of clay used. These greenhouse cover films should allow the pass-through of visible light into the greenhouse during day but restrict the pass-through of the infrared radiation out of the greenhouse during night. [ABSTRACT FROM AUTHOR]

A simple, effective, and inexpensive method has been developed to fabricate superhydrophobic surfaces based on low-density-polyethylene/ethylene–propylene–diene terpolymer thermoplastic vulcanizate. Field emission scanning electron microscope research showed that the rough microstructure could be fabricated successfully in the thermoplastic vulcanizate surface where metallographic sandpaper was used as molding template; moreover, the micrometer scale plastic deformation of thermoplastic vulcanizate matrix could be observed obviously, leading to the increasing surface roughness. Wettability test showed that the series rough thermoplastic vulcanizate surfaces that were molded with sandpapers had strong hydrophobic property; furthermore, the sliding angle value was less than 10°. Metallographic sandpaper template exhibited well re-used property. [ABSTRACT FROM PUBLISHER]

In this study, TiO2nanoparticles were incorporated into low-density polyethylene by melt blending. Morphological properties and dispersion behavior of TiO2nanocomposite were characterized through field emission scanning electron microscope, X-ray diffraction, and Fourier transform infrared spectroscopy. Thermal stability of the nanocomposites was determined by thermogravimetric analysis. Moreover, the mechanical properties of nanocomposites were determined. Antimicrobial activity of TiO2nanocomposites was investigated by in vitro test. Dispersion of the nanoparticles was good in nanocomposites.According to thermogravimetric analysis, incorporation of TiO2nanoparticles into low-density polyethylene enhanced the thermal stability. Mechanical properties of nanocomposites were improved by TiO2nanoparticles. Results showed that the antibacterial effect of low-density polyethylene –TiO2nanocomposite was significantly enhanced by TiO2nanoparticles (p < 0.05). The number of surviving bacteria was decreased considerably. Finally, this study showed that the TiO2nanoparticles not only can improve the properties of low-density polyethylene but they also have the potential to be used as an active food packaging film. [ABSTRACT FROM AUTHOR]

Linear low density polyethylene (LLDPE) and high density polyethylene (HDPE) (with different shear thinning behaviors) were melt blended at two different compositions (10 and 25 wt%. of HDPE) and three different rotational speeds. Batch foaming process was performed over a wide range of temperatures. Bulk density measurement, cell structure evaluation, differential scanning calorimetry (DSC), and oscillatory rheology tests were performed. Results indicated the deterioration of foamability for those blended at the highest selected speed of 120 rpm. The blends mixed at a speed of 60 rpm, exhibited a slightly lower expansion ratio compared with those of mixed at a speed of 10 rpm with the same trend over the foaming temperature. For blends with 25 wt%. HDPE, proper cellular structures were obtained through a broader range of foaming temperature. [ABSTRACT FROM AUTHOR]

A series of electrically conducting low density polyethylene/poly(p-azidoaniline) blends containing different loadings of poly(p-azidoaniline) was prepared. The resistance of these blends to accelerated thermal oxidation at 90°C for different time intervals was investigated. The thermal degradation mechanism was determined by attenuated total reflection-Fourier transform infrared technique. The values of melting temperature (Tm), enthalpy of fusion (ΔHm), and degree of crystallinity showed significant increase upon poly(p-azidoaniline) addition. X-ray diffraction patterns also confirmed increase in degree of crystallinity upon blend formation. Furthermore, scanning electron microscopy observations showed efficient thermal stabilization of low density polyethylene/poly(p-azidoaniline) blends. The mechanical properties showed significant role of poly(p-azidoaniline) as thermal stabilizer for low density polyethylene. [ABSTRACT FROM PUBLISHER]

Current work focuses on establishing optimal growth conditions for covering commercial grade polymer blown films with a gas barrier oxide layer. As opposed to regular solid state substrates, low density polymers host an abundance of free space in the form of pores and voids between large polymer chains (MW > 1000) and a heterogeneous crystallized phase. In the following we will show how the structural peculiarities of the polymer matrix influence the ALD process for growing TiO2and Al2O3gas blocking layers on top of the LDPE substrate. Possible causes of low gas barrier performance, thermal expansion coefficient differences, are proposed and commercial process additives, such as slip or antioxidants, are suggested. [ABSTRACT FROM PUBLISHER]

Nypa Fruticans fiber (NFF) was used as filler in polylactic acid (PLA) and recycled low density polyethylene (rLDPE) biocomposites. The biocomposites were prepared by using a Brabender Plasticorder EC Plus. The effects of NFF content and Ultra-Plast TP01 (TP01) on the tensile properties and morphology were investigated. The effect of NFF content decreased the tensile strength and elongation at break of biocomposites, but increased Young’s modulus. The compatibilization of NFF and PLA/rLDPE biocomposites was improved with addition of Ultra-Plast TP01 as compatibilizer. It was found that the tensile strength and Young’s modulus of biocomposites with TP01 higher than biocomposites without TP01. The resulting FTIR spectra of biocomposites with TP01 showed the change in hydrophilic NFF to become hydrophobic. Furthermore, the morphology study of biocomposites indicated that the presence of TP01 enhanced the interfacial interaction between NFF and PLA/rLDPE matrix. [ABSTRACT FROM AUTHOR]

The role of nanoclays and TiO2nanoparticle loadings were investigated on low density polyethylene crystalline structure, in addition to studying packaging film properties such as barrier, thermal and mechanical properties. The polymer crystal study indicated for the orthorhombic crystal phase and about 20% lower degree of crystallinity for nanocomposites containing more than 2 wt.% TiO2nanoparticles. Based on the X-ray diffraction technique, the dispersion of nanoclays was improved to almost good degree of clay exfoliation with the company of 4 wt.% TiO2nanoparticles. In agreement with XRD results, the TEM morphological studies mainly suggest that TiO2has a helpful effect on nanoclay exfoliation. The increase in degradation temperature of nanocomposites may be attributed to the formation of inorganic char on polymer melt. The barrier properties of TiO2/clay nanocomposite packaging films depend mainly on nanoclay loading with an unclear trend from TiO2nanoparticles. The increase in elastic modulus and the yield stress of nanocomposite films showed great effects on film mechanical properties by nanoclays. [ABSTRACT FROM AUTHOR]

This article deals with the effect of electron beam irradiation and flame-retardant loading on the performances of LDPE-based formulations for wire and cable applications. In this study the influence of electron beam irradiation on different blends of low density polyethylene (LDPE) filled with aluminum trihydrate (ATH), magnesium hydroxide (MH), and calcium carbonate (CaCO3) were studied. The mechanical, thermal, and burning properties of the resulting polymer networks have been analyzed and discussed. Addition of all non-halogenated fillers to LDPE deteriorated the mechanical properties. Addition of MH to LDPE presented a significant increase on adhesion forces inside polymer matrices and acted more efficiently than similar ATH/LDPE and CaCO3/LDPE compounds. LDPE flame retardancy improved significantly by a carbonaceous, non-flammable coating formation with high plasticity of CaCO3addition at high temperature. The resulting MH blends were more efficient thermally and burned more stably than similar ATH blends. It was also concluded that electron beam irradiation had improved effects on thermal stability and mechanical properties for all the polymeric samples in this research. [ABSTRACT FROM AUTHOR]

Morphology, thermal degradation and kinetics of metallocene-linear-low-density polyethylene (m-LLDPE)/m-LLDPE-graft-maleic anhydride (m-LLDPE-g-MA)/nanoclay nanocomposites were compared with m-LLDPE/nanoclay, m-LLDPE-g-MA/nanoclay and m-LLDPE/m-LLDPE-g-MA systems. X-ray diffraction measurements revealed intercalated and “highly intercalated” morphologies for the nanocomposites. Thermogravimetric analysis demonstrated that although thermal degradation of m-LLDPE systems were delayed upon the inclusion of nanoclay in air, an inverse effect was perceived for the nanoclay under inert atmosphere. This conclusion was supported by kinetic analysis in terms of reaction order and activation energy. The results obtained from kinetics models also put forward the contribution of m-LLDPE-g-MA, as a compatibilizer, to the thermal stability enhancement through inter-molecular cross-linking augmentation. [ABSTRACT FROM PUBLISHER]

In order to examine the effect of the modified nanofiller on polyethylene matrix, Cloisite 20A is treated with various types of additives as calcium carbonate, silane, stearic acid and dibenzoyl peroxide. Polyethylene nanocomposites were prepared by extrusion on twin-screw extruder using differently modified nanofiller. The results of FTIR analysis show that disorder of nanofiller structure is obtained, i.e., the chemical bonding between the components is occurred. XRD analysis shows the shift of characteristic peaks of modified filler, which indicates the formation of delaminated and/or intercalated structures. The results of thermogravimetric analysis point to different mechanisms of degradation of polyethylene nanocomposites. [ABSTRACT FROM PUBLISHER]

Electron beam irradiation efffects on polymer cross-linking used for wire and cable insulations are still being researched. This study showed that upon irradiation, ethylene vinyl acetate (EVA) and maleic anhydride grafted polyethylene (LDPE-g-MAH) addition as coupling agent to the LDPE/fillers, improved processing and mechanical properties of compounds at each irradiation dosage (0–110 kGy). A gradual increase in gel content (GC) and tensile strength (TS) with a concomitant decline in elongation at break (EB), hot set (HS) and densities of compounds were observed upon irradiation of the blends. Melt flow index test (MFI) results revealed that filler addition reduced compounds flowing and in consequence, caused difficult to process. The LDPE/EVA blends TS values decreased significantly with fillers addition (ATH, MH and ZB). Consequently, this study demonstrated that filler addition to irradiated low density polyethylene (LDPE) impaired processing and mechanical properties of compounds, whereas, LDPE-g-MAH (6–12 phr) and EVA (0–100 phr) addition to the compounds (1I–8I) improved the blends flowability and mechanical properties at each irradiation dose (0–110 kGy). Moreover, among additive fillers, MH content compounds presented the strongest adhesion forces with polymeric compounds compared with analog compounds content aluminum trihydrate (ATH) or zinc borate (ZB) at each irradiation dosage. [ABSTRACT FROM PUBLISHER]

Higher filler loading in incompatible polymer blends generally leads to catastrophic deterioration of physico-mechanical properties. This investigation reports effect of an elastomeric compatibili-zer on the mechanical properties of carbon black (CB) filled immiscible Polypropylene (PP)/Low density polyethylene (PE) blends. The composites were prepared by melt compounding of PE, PP, ethylene propylene diene monomer (EPDM) and CB in different proportions. Elongation at break for 30wt.% CB-filled PE/ PP (1:1) blends did not show any improvement up to 10wt.% EPDM addition, suggesting absence of any comptabilization effect of EPDM in CB-filled blends, whereas unfilled blends exhibited good comptabilization and about 200% improvement in elongation at break was observed at 10wt.% EPDM content. DSC studies revealed good interactions between PE and EPDM phases, and there was no reduction in the crystallinity of either PE or PP phases up to 50% EPDM loading. The phase inversion was observed in 50–75wt.% EPDM loading. The micromechanical modeling of the composite suggests selective incorporation of CB in PE and EPDM phases. The results have been explained in the light of the percolation of carbon black in different phases and the role of EPDM as a compatibility modifier of PE and PP phases. [ABSTRACT FROM PUBLISHER]

Low density polyethylene films were grafted by poly (acrylic acid). The effects of dose, monomer concentration, solvent, inhibitor and thickness of films were investigated. Adsorption capacities of grafted films of Pb2+and Cd2+reached up to 20 and 13 (mg/g), respectively. The complexed grafted films in protection of workers against technetium-99 m radiation dangers were investigated. The effects of grafting percentage, thickness and adsorption capacity of ions on shielding efficiency were studied. The transmission intensity of complexed grafted films decreased gradually until arrived almost 0%. The protection efficiency of complexed grafted films is higher than grafted and virgin films, respectively. [ABSTRACT FROM AUTHOR]

In this work, halloysite nanotubes (HNTs) were hybridized with kenaf core fibers (KCF) to reinforce low density polyethylene (LDPE)/thermoplastic sago starch (TPSS) blends. The effects of HNT loading (3–15 wt.%) on the mechanical and physical properties were examined. The results showed an enhancement in tensile strength and modulus with the inclusion of HNTs. Formation of FTIR bands that are assigned to Al-OH and Si-O vibrations indicated the presence of HNTs in the system. Moreover, the thermal stability of hybrid composites was improved with the addition of HNTs. Water uptake decreased as higher amount of HNTs imparted to the hybrid composites. [ABSTRACT FROM AUTHOR]

PE-LD samples containing two types of filler in concentrations of 2–10 wt.% (zeolite TMAZ 7 and nanoclay Cloisite 20A). The microstructural and morphological changes as well as mechanical features of samples were characterized by scanning electronic microscopy (SEM) and by tensile tests. The thermal degradation of PE-LD composites were achieved using thermogravimetric analysis (TGA). The permeability, the diffusion and the solubility constants of the gases in modified PE-LD films were calculated and the gas separation (N2/O2; O2/CO2) ability was determined. In the presence of nanoparticles, at lower content, the value of oxygen permeability of PE-LD decreases. [ABSTRACT FROM PUBLISHER]

A simple method for the preparation of magnetic nanocomposites consisting of NiFe2O4nanoparticles, polybenzoxazine (PB), linear low-density polyethylene (LLDPE) and LLDPE-g- Maleic anhydride (LgM) is described. Composites were prepared by forming benzoxazine- NiFe2O4nanocomposites followed by melt blending with LLDPE and thermal curing of benzoxazine. The composites were characterized by XRD, DSC and TGA, FT-IR, SEM, UTM and VSM. The saturation magnetization of the composites containing 33.25 wt% NiFe2O4was 7.72 emu/g and it decreased with decreasing amount of NiFe2O4in the composite. The composite films exhibited mechanical flexibility as well as magnetic properties. [ABSTRACT FROM AUTHOR]

A novel linear low-density polyethylene (LLDPE)/polypropylene (PP) blends were prepared by melt blending with moderate cross-linked LLDPE/PP blend (LLDPE–PP) as compatibilizer, the rheological properties associated with the morphological structure of the LLDPE/PP/LLDPE-PP blends were studied by SEM, capillary rheometer, HAAKE torque rheometer and melt fiow rate instrument. The results showed that adding LLDPE-PP in the blends improved compatibility between LLDPE and PP phases, made the pseudo plastic behavior of the melt decrease and the melt viscosity and the balance torque increase slightly. Moreover, in the range of high shear rate, the die-swell ratio of the blends decreased with increasing LLDPE-PP content. [ABSTRACT FROM AUTHOR]

The effects of polyethylene grafted maleic anhydride on tensile properties, morphology, thermal degradation, and swelling behavior of low density polyethylene/chicken feather fiber composites were studied. The LDPE/CFF composites were prepared using a Z-Blade mixer at 180°C and rotor speed of 50 rpm for 15 min. LDPE/CFF/PEgMAH composites exhibit higher tensile strength, Young's modulus, and final decomposition temperature, but lower mass swell percentage and elongation at break than LDPE/CFF composites. SEM morphology showed that the chicken feather fiber more widely dispersed in the LDPE matrix with the addition of polyethylene grafted maleic anhydride as a coupling agent. It was also found that the addition of PEgMAH offers better thermal stability in LDPE/CFF/PEgMAH composites than LDPE/CFF composites. [ABSTRACT FROM AUTHOR]

Polylactide (PLA)-based wood plastic composites (WPCs) were manufactured to investigate the effects of linear low density polyethylene (LLDPE) on the resulting composites, which were fabricated through extrusion blending followed by injection molding. The static and dynamic mechanical, and thermal properties of the PLA-based WPCs were tested and the morphologies of the cryofractured surface were observed. The impact toughness and interface adhesion of the PLA-based WPCs toughened with LLDPE were significantly improved, compared with their unmodified counterparts. LLDPE had no significant effect on the thermal stability of the PLA-based WPCs and could be an advisable toughening agent for the PLA-based WPCs. [ABSTRACT FROM PUBLISHER]

This study investigated nanocomposites based on low density polyethylene containing 2, 3, 5 and 7 wt% potassium permanganate (KMnO4) nanoparticles as a new novel material used for film packaging in fruit industry. This work included preparation and modification of nano-KMnO4, fabrication and characterization of the nanocomposites. Presence of filler caused reduction in degree of crystallinity that was confirmed by WXRD and DSC analysis. Barrier properties of nanocomposite against oxygen were improved up to 24%. [ABSTRACT FROM PUBLISHER]

Montmorillonite (MMT) was first modified with dodecyl dimethylbenzyl ammonium (DDA) salt and octadecyl trimethyl ammonium (OTA) salt. Then low density polyethylene (LDPE)/organic montmorillonite (OMMT) nanocomposites were prepared by twin-screw extruder and hot-press. Transmission electron microscopy (TEM) results showed that OMMT layers were homogeneously intercalated into the LDPE matrix. In terms of MMT, the modification effect of OTA is superior to that of DDA. CO2 and O2 barrier properties of nanocomposites were increased by 7 times and 4 times with 0.5 wt.% OTA-MMT loading, respectively. At 2 wt% OTA-MMT loading, water vapor permeability of LDPE has also decreased about 2.5 times. Compared with pure PE film, 49.5% and 178% improvement of tensile strength of nanocomposites films were obtained by addition of only 4 wt.% DDA-MMT and OTA-MMT, respectively. In addition, with only 0.5 wt.% OMMT loading, the onset degradation temperature of nanocomposites increases by 23°C and 26°C for LDPE/DDA-MMT and LDPE/OTA-MMT, respectively. [ABSTRACT FROM AUTHOR]

To attain improved mechanical properties of the carbon fiber reinforced low density polyethylene (LDPE) composites (CF/LDPE), CF was deposited with TiO2. The short beam shear and mechanical properties of CF/LDPE composites have been investigated. The mechanical properties of the composites prepared from TiO2-deposited CF are found to be much better compared to those of untreated ones. Tensile strengths of the composites of both raw and TiO2 deposited CF/LDPE composites showed an increasing trend with increasing filler content. The surface morphologies of the fractured surfaces of the composites were recorded using scanning electron microscopy (SEM) to gain information about the fiber–matrix interfacial adhesion in the composites. [ABSTRACT FROM AUTHOR]

A reactive type dripping agent, glycerol monolauric acid monoitaconic acid diester (GLID) was synthesized in our laboratory. Grafting-copolymerization of linear low density polyethylene (LLDPE) with GLID was carried out by using β-ray irradiation in air in a twin-screw extruder. FT-IR was used to characterize the formation of grafting copolymer and evaluate their degree of grafting. The effects of monomer concentration, reaction temperature and screw run speed on degree of grafting were studied systematically. Crystallization rates of grafted LLDPE were faster than that of plain LLDPE at a given crystallization temperature. The tensile properties and light transmission of blown films were determined. Comparing with neat LLDPE film, no obvious changes could be found for the tensile strength, elongation at break and right angle tearing strength of LLDPE-g-GLID film. Acceleration dripping property of film samples was investigated. The dripping duration of LLDPE-g-GLID film and commercial antifog dripping film at 60° C were 69 days and 17 days, respectively. [ABSTRACT FROM PUBLISHER]

The effect of vinyl alcohol-phthalic anhydride as a coupling agent on the tensile properties, morphology, and thermal degradation of low density polyethylene/tyre dust (LDPE/TD) composites was studied. LDPE/TD composites with different tyre dust loading and the addition of vinyl alcohol-phthalic anhydride were prepared with Z-blade mixer at 180°C and rotor speed of 50 rpm. The result indicated that LDPE/TDM composites with vinyl alcohol-phthalic anhydride show higher values of tensile strength, Young's modulus and mass swell, but lower elongation at break than LDPE/TD composites without vinyl alcohol-phthalic anhydride. The SEM micrographs showed that the tyre dust was more widely dispersed in the LDPE matrix with the addition of vinyl alcohol-phthalic anhydride as a coupling agent. It was also found that the addition of vinyl alcohol-phthalic anhydride offers better thermal stability in the LDPE/TDM composites than LDPE/TD composites. [ABSTRACT FROM PUBLISHER]

The effect of compatibilizer (LLDPE-g-MA) on mechanical, thermal, morphological and water absorption properties of Nylon-6/LLDPE blends was investigated. SEM analysis and image processing revealed coarse biphasic morphology with LLDPE dispersant size in the range of 1.97–2.23 µm for uncompatibilized blends wherein compatibilized blends showed smooth morphology with dispersant size in the range of 0.76–1.34 µm. Compatibilization effect has also been supplemented by thermal studies showing shift in crystalline melting point of Nylon-6 in compatibilized blends reflecting improved interfacial interaction. Compatibilized blends showed 10–25% overall improvement in mechanical properties and 15–35% reduction in water absorption as compared to uncompatibilized blends. [ABSTRACT FROM AUTHOR]

The effect of phthalic anhydride as a new coupling agent on the properties of low density polyethylene/tyre dust (LDPE/TD) composites was studied. LDPE/TD composites with different tyre dust filler loading and the addition of phthalic anhydride were prepared with Z-blade mixer. The result indicated that LDPE/TDM composites with phthalic anhydride show higher tensile strength, modulus of elasticity, thermal stability and swelling resistance than LDPE/TD composites. The interfacial adhesion between LDPE and TD was improved with the addition of phthalic anhydride as evidenced by the morphological study. [ABSTRACT FROM PUBLISHER]

LLDPE/LDPE blend films were prepared using a Brabender extruder by melt blending and blowing. The research results indicated that addition of LDPE has no significant effect on the melting temperature of LLDPE, but the crystallinity as well as spherulite size of the blends decreases. In addition, with increasing content of LDPE, the tensile properties of blend films decline, on the contrary the tear strength enhances in a certain degree. The decrease of melt viscosity of the blends comparing with pure LLDPE suggests that LDPE could improve the melt rheological property of LLDPE. [ABSTRACT FROM AUTHOR]

Proteins were isolated from deoiled cakes (DOC) of soybean, castor and rapeseed. The isolated proteins were then blended with LDPE in different wt. ratios, using PEG400 as a plasticizer. The morphology of the blends was evaluated by using a scanning electron microscope (SEM). Homogeneous blends were obtained and analyzed for various mechanical properties such as tensile strength, impact strength, hardness and % elongation and compared with properties of plastic sheets prepared from mixture of pure proteins. Results revealed that protein composition and amount of LDPE in proteins and LDPE blend, affects the mechanical properties of the plastic compositions considerably. [ABSTRACT FROM AUTHOR]

Low density polyethylene (LDPE)/maleic anhydride grafted polyolefin elastomer (POE-g-MA) with multiwall carbon nanotubes (MWCNTs) wrapped by fumed silicon dioxide (SiO2) were prepared by melt mixing. The results revealed that SiO2 improved the dispersion of MWCNTs on matrix. SiO2 and MWCNTs both had a heterogeneous nucleation effect on matrix and the crystallinity of composites increased with adding SiO2, MWCNTs and MWCNTs/SiO2. The addition of MWCNTs modified by SiO2 increased tensile strength and elongation at break of composites compared with composite with raw MWCNTs. MWCNTs had a strong absorption effect, leading to an obvious decrease in reflectance at 1060 nm of composites. [ABSTRACT FROM AUTHOR]

Nanocomposites of linear low-density polyethylene (LLDPE)/natural rubber (NR)/liquid natural rubber (LNR) blend denoted as TPNR with montmorillonite-based organoclay (OMMT) were prepared using melt blending method. The melt blending of LLDPE/NR/LNR with a composition of 70:20:10 formed blends. For better dispersion of nanoclay in the TPNR blend, MA-PE was used as a coupling agent. The nanoclay dispersion was investigated by X-ray diffraction (XRD), and a novel method using permeability measurements data in a permeability model. The measured d-spacing data proved a good dispersion of nanoclay at low clay contents. The permeability model for flake-filled polymer was used to estimate the aspect ratio of nanoclay platelets in the blend nanocomposites. The oxygen barrier property of the TPNR blend improved about two-fold by adding only 2 wt% of organoclay. Differential scanning calorimetry showed an increase in cystallinity up to 20% suggesting an increase in spherulite growth, by the increased in melting temperature. The increase in the barrier property of the blend with the induction in crystallinity indicates the dominant role of organoclay platelets in barrier improvement. Scanning electron micrographs of tensile fracture surface of the nanocomposite, exhibited a very ductile surface indicating a good compatibility of LLDPE and NR and also, a possible contribution of nanoparticles to the deformation mechanism, such as extensive shear yielding in the polymer blend. The transmission electron micrograph, showed an intensive intercalation structure and exfoliation structure with the presence of MA-PE. [ABSTRACT FROM AUTHOR]

Functional fiber based on butyl methacrylate-hydroxyethyl methacrylate copolymer and low density polyethylene was prepared via the method of gelation-spinning, and then the kinetics model and mechanism of organic matter absorption into the functional fiber were investigated. The results show that a lot of microvoids are constructed within the cross section of the functional fiber, but the microvoids do not make a significant contribution to the absorption of organic matter. The functional fiber can absorb toluene at a quick rate, while it can absorb trichloroethylene and chloroform at a relatively slower rate. The swelling capability of the blend fiber in selected organic matter is weaker than the one of butyl methacrylate-hydroxyethyl methacrylate copolymer fiber, and the swelling behavior is controlled by stress relaxation in the amorphous portion of the polymer blend network. Furthermore, second-order kinetics model is more suitable for describing the process of organic matter absorption than first-order kinetics model. [ABSTRACT FROM AUTHOR]

Jute fabrics (50%)-reinforced linear low density polyethylene (LLDPE) composite was prepared by compression molding and mechanical properties were studied. Gelatin fiber (2%–10%) was incorporated into the jute fabrics-based composites and their mechanical properties were investigated and compared with the control composite. It was found that with the increased of gelatin fiber content in the jute fabrics-based composites, the mechanical properties were found to be decreased, but water uptake and degradation properties were increased significantly. The composite containing 10% gelatin fiber lost 30.2% of its weight, 56.4% TS, 41.8% BS, 26% TM and 25.5% BM after 24 weeks in soil medium. [ABSTRACT FROM PUBLISHER]

The melt compounding technique was employed to prepare thermoplastic natural rubber (TPNR) nanocomposites. The maleic anhydride grafted polyethylene (MA-PE) as a coupling agent was used to improve the filler-matrix interfacial adhesion. TPNR were prepared in the ratio of (70:20:10) from linear low-density polyethylene (LLDPE), natural rubber (NR) and liquid natural rubber (LNR) as a compatibilizer between the matrix. The composites were prepared using the in-situ method at the optimum processing parameter at 140°C with 100 rpm mixing speed and 12 minutes processing time. The results of the tensile test showed that the optimum of clay loading was obtained at 4 wt%. Dynamic mechanical analysis (DMA) was performed to investigate the thermomechanical properties of the composites. The results show that the addition of organoclay has improved the storage modulus (E′) and loss modulus (E′′) of TPNR nanocomposites. The α transition peaks was also shifted to the higher temperature. However, nanocomposites with MA-PE demonstrated higher, E′ and E′′ compared to TPNR nanocomposites without MA-PE. The TEM results show good clay dispersion with a combination of intercalated-exfoliated structure in the TPNR matrix. [ABSTRACT FROM PUBLISHER]

The compatibility and crystallization behavior of LLDPE blended with the three different molecular weights of NR were studied. The obtained single derivative decomposition peak from TGA measurements for LLDPE blended with the lowest molecular-weight natural rubber [image omitted] clarified the improved compatibility between LLDPE and NR. The reduction of the crystallinity and the change of α-relaxation temperature of LLDPE in the blend were significant. It is interesting that the mechanical properties including the elongation at break and the impact strength of LLDPE were found to be enhanced by adding this low molecular-weight NR without using a compatibilizer. [ABSTRACT FROM AUTHOR]

Polylactide (PLA)/linear low density polyethylene (LLDPE) was produced by different mixing type, provided by combining different single screw elements. The relationship between rheological responses and morphology of the blends was investigated. It is shown from rheological curves that different morphology is reflected to be formed in blends produced by different mixing type. Han plots, van Gurp-Palmen plots and cole-cole curves show that a stronger interaction between polymer minor and matrix or co-continuous morphology appears in PLA/LLDPE (70/30) produced by high shear/chaotic mixing. This is in agreement with the results of morphology observation. In addition, the crystallization of blends is analyzed. Results show that the crystallity of blends produced by shear/chaotic mixing is decreased, due to the stronger interaction between the two phases in blends. [ABSTRACT FROM AUTHOR]

A protein-based natural polymer, soya powder, was melt blended with linear-low density polyethylene (LLDPE). Cobalt stearate (CS) was used as a pro-oxidant. The blends were exposed to natural weathering for 6 months. The susceptibility of the LLDPE/soya powder, based on its tensile properties, morphology, thermal behaviour and chemical and physical changes was measured every three months. The tensile strength and elongation at break (Eb) of the blends with CS were more susceptible compared to the blends without CS. During weathering, the crystallinity and weight loss increased with the addition of CS in the blends, however molecular weight was reduced. [ABSTRACT FROM AUTHOR]

The effect of poly(methyl methacrylate) modified water hyacinth fiber on properties of low density polyethylene (LDPE)/natural rubber (NR)/water hyacinth fiber (WHF) composites were investigated. The composites were prepared with Z-blade mixer at 180°C and rotor speed of 50 rpm. The poly(methyl methacrylate) modified water hyacinth fibers in LDPE/NR composites (LDPE/NR/WHF-PMMA) gave a greater value of tensile strength, Young's modulus, glass transition temperature (Tg), melting temperature (Tm), and % crystallinity compared to unmodified water hyacinth fibers in LDPE/NR composites (LDPE/NR/WHF). FTIR analysis shows the presence of ester carbonyl group and C-O ester group in poly (methyl methacrylate) modified water hyacinth fiber. The SEM micrograph also shows a better interfacial adhesion between the fibers and LDPE/NR matrixes for LDPE/NR/WHF-PMMA composites than LDPE/NR/WHF composites. LDPE/NR/WHF-PMMA composites had a lower value of interparticle spacing compared to LDPE/NR/WHF composites thatenhanced the interparticle interaction between fiber and LDPE/NR matrixes. [ABSTRACT FROM AUTHOR]

This study examines the production of linear low density polyethylene (LLDPE)/soya powder blends to be used as alternatives to cellulosic material/polyolefin blends. LLDPE was blended with soya powder in a Haake internal mixer by melt mixing. Composition of the soya powder was varied from 5 wt% to 40 wt%. Polyethylene grafted maleic anhydride (PE-g-MA) was used as a compatibiliser. Environmental degradation was evaluated by composting the blends sample into the soil. It was found that for a higher soya powder composition, the degradation rate increased. Blends with compatibiliser degraded at lower rates than the uncompatibilised blends. The carbonyl indices of uncompatibilised blends subjected to the soil burial test were found to be higher than compatibilised blends. The weight loss changes in time data was collected and used to estimate the further changes by curve-fitting method. The complete degradation of the blends can be estimated from the kinetic curve. DSC results indicate that the crystallinity of the blends increased with increasing soya powder content added after composting. [ABSTRACT FROM AUTHOR]

Position dependence for the supermolecular morphology of linear low density polyethylene (LLDPE) prepared by gas-assisted injection molding (GAIM) was examined using scanning electron microscopy (SEM). Combined morphological feature of both spherulites and those with ring-bands was observed, which differs from our previous studies on the HDPE counterparts. Dynamic rheological measurements were also carried out to interpret the formation mechanism of the morphological feature. The difference in hierarchical crystalline structures between LLDPE and HDPE can be due to their different chain branches as well as the resultant different response to the local shear fields during the GAIM process. [ABSTRACT FROM AUTHOR]

Thermally conductive composite film was obtained from silicon carbide (SiC) and linear low-density polyethylene (LLDPE) by powder mixing and hot press molding. SiC powder distributions were found to be relatively rather uniform at both low (20 wt.%) and high (60 wt.%) filler content. The effect of the content and the particle diameter of filler on the properties of SiC/LLDPE composites was investigated by thermal conductivity measurement, TGA, tensile test and dielectric properties measurement. The results demonstrated that the thermal conductivity and dielectric constant of LLDPE film increased from 0.32 Wm-1 K-1 and 2.10 to 0.98 Wm-1 K-1 and 4.18 with 50 wt.% SiC loading. The TGA data showed SiC filler slightly increased the thermal stability of LLDPE. While the tensile properties of LLDPE obviously decreased with the increase of SiC. Compared with the untreated SiC filler, KH-550 slightly improved the thermal conductivity of SiC/LLDPE composites. For thermal conductivity, smaller particle is superior to larger particle. Compared to that with single-scale particle, the composites filled with hybrid SiC particle exhibited higher thermal conductivity. [ABSTRACT FROM AUTHOR]

The effect of isophorone diisocyanate-polyhydroxyl groups as a coupling agent on properties of low density polyethylene/acrylonitrile butadiene styrene/water hyacinth fibers (LDPE/A0BS/WHF) composites was studied. LDPE/ABS (50/50) blends with different unmodified and modified water hyacinth fibers (WHF) loading were prepared with Z-blade mixer at 200°C and rotor speed of 50 rpm. The results indicated that LDPE/ABS/modified WHF composites show higher values of tensile strength, Young's modulus and water absorption resistance than LDPE/ABS/unmodified WHF composites. It was also found that the modified WHF offers better thermal stability than unmodified WHF in the LDPE/ABS/WHF composites. [ABSTRACT FROM AUTHOR]

Calcium carbonate (CC) and carbon black (CB) filled composites based on linear low density polyethylene (LLDPE) and ethylene-octene copolymer (POE) were prepared by means of melt blending. The microwave absorbing performances were measured using the arch method and the electromagnetic parameters of composites were determined by transmission/reflection method. The structure and surface morphology were observed using transmission electron microscopy (TEM). LLDPE/POE/CC/CB composites show excellent microwave absorption ability. The dielectric loss from the filler CB is responsible for the microwave absorption of polymer composites. CB can effectively improve the mechanical properties of LLDPE/POE/CC composites. [ABSTRACT FROM AUTHOR]

Composites of low density polyethylene were prepared by melt mixing in a co-rotating twin screw extruder. Castor presscake, a biodiesel process co-product, was used as filler for the polyethylene composites. Different concentrations of this filler were added to the polymer matrix. Melt flow index and. mechanical properties were measured by following standardized tests. The results showed that the addition of the filler to the polymer matrix provoked an increase on the values of Young Modulus and on the flexural properties. However, the impact strength and the tensile stress values tended to decrease with the increasing of the filler concentration. [ABSTRACT FROM AUTHOR]

This paper reports the study of microcellular injection molding of low-density polyethylene- (LDPE) based composites. The effects of adding nanoclays and polymer additives in LDPE as well as rheological property of materials on the cell morphology, mechanical properties and surface properties of microcellular injection molded LDPE based composites are presented. For the microcellular injection molding process, when 3 wt% of nanoclays are added into LDPE-based polymers, the cell morphology can be significantly improved due to the nucleating effects resulting from the broad interface areas between polymer and nanoclays. Also, the addition of low melt flow LDPE into high melt flow LDPE could achieve smaller and denser bubbles in the polymer matrix than neat high melt flow LDPE. [ABSTRACT FROM AUTHOR]

Low density polyethylene (LDPE)/modified water hyacinth fiber (WHF) composites have been prepared by melt blending. All the composites were characterized by tensile test, differential scanning calorimetry (DSC), water absorption behaviour, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The results indicated that LDPE/WHF composites with NCO-polyol as a coupling agent show higher values of tensile strength, Young's modulus and water absorption resistance but lower elongation at break than LDPE/WHF composites without NCO-polyol. The micrographs of SEM showed that the WHF were more widely dispersed in the LDPE matrix with the addition of the NCO-polyol as a coupling agent. It was also found that the modified WHF offers better thermal stability in the LDPE/WHF composites than unmodified WHF. [ABSTRACT FROM AUTHOR]

The effect of cobalt naphthenate on photo degradation of low density polyethylene was studied. The carbonyl index, tensile strength, elongation at break, density and relative crystallinity of the samples were measured. The samples were made of different concentrations of LDPE and cobalt naphthenate. Parts of uniform thickness were cut for testing before and after UV-irradiation at every 30-days interval for 90 days. From the results of FTIR, and other measurements, it was observed that the UV-irradiation affects on the LDPE films and the rate of degradation increased with increasing both the concentration of the photosensitizer and time of irradiation. [ABSTRACT FROM AUTHOR]

The effect of waste office white paper (WOWP) loading and size on mechanical properties, morphology and thermal properties of LDPE/WOWP composites were investigated. The results showed that increasing of WOWP loading has increased tensile strength and Young's modulus but decreased elongation at break of composites. LDPE/WOWP composites with smaller particle size (31 μm) have higher mechanical properties. Thermal analysis results of composites with particle size (31 μm) show higher thermal stability and crystallinity than composites with particle size (77 μm). Scanning electron microscope (SEM) micrograph indicates that the smaller particle size of filler has better interaction with LDPE matrix. [ABSTRACT FROM AUTHOR]

In this work, normal blends, microfibrillar blends and composites were prepared from low density polyethylene (LDPE) and poly(ethylene terephthalate) (PET) in 85/15 and 75/25 w/w% ratio in the presence and absence of a compatibilizer polyethylene grafted with maleic anhydride (PE-g-MA). The microfibrillar composites (MFCs) were prepared using extrusion - drawing - isotropization technique. The morphology development of the microfibrillar blends and composites was studied using scanning electron microscopy (SEM). The presence of 5 wt% PE-g-MA compatibilizer affected the continuity of the fibrils differently in 75/25 and 85/15 w/w% microfibrillar blends. In the case of normal blends the addition of compatibiliser reduced the size of the dispersed PET phase. The presence of PET microfibrils improved the tensile properties of the microfibrillar composites. The normal blends exhibited a relatively ductile failure during tensile loading in comparison with the microfibrillar composites. The microfibrillar nature of the dispersed phase was found to improve the stiffness of the composite rather than their impact strength. [ABSTRACT FROM AUTHOR]

The effect of polyethylene-grafted maleic anhydride (PE-g-MAH) on the tensile properties, morphology and thermal properties of low-density polyethylene (LDPE)/eggshell powder (ESP) composites was studied. LDPE/ESP composites with different eggshell powder content and the addition of PE-g-MAH were prepared with Z-blade mixer at 180°C and rotor speed of 50 rpm. The tensile strength, elongation at break and thermal stability of LDPE/ESP composites with PE-g-MAH were greater than LDPE/ESP composites, and their differences became more pronounced at higher filler content. The interfacial adhesion between ESP and LDPE was improved with the addition of PE-g-MAH as evidenced by the morphological study. [ABSTRACT FROM AUTHOR]