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Publications (340)
The peel strength of aluminium-aluminium joints bonded by an adhesive based on ternary 75/25/175 poly(vinyl chloride)/epoxidised natural rubber/carboxylated nitrile rubber blends was found to depend on moulding time. Dynamic mechanical studies of the Al-blend-Al composite structures provide useful information on adhesion. In addition, the composite...
Effects of laser irradiation on the thermal properties and morphological structure of starch, polyvinyl alcohol (PVA) and their blends were studied. Laser irradiation has an insignificant effect on the thermal behaviour of starch and PVA, but it causes an increase in crystallization and melting temperature (T cry and Tm ) for blends as a function o...
This paper reports the results of studies on the effect of aspect ratio of multiwall carbon nanotubes (CNT) on the shear and extensional rheological behavior of low density polyethylene (LDPE) nanocomposites. Up to a CNT loading of 2 wt%, as used in the present study, the shear rheological data suggest no network formation in the nanocomposites, ir...
Poly(acrylic acid) polymer blends comprising poly(acrylic acid) and glycerol, the glycerol content being 25-75% by weight based on the weight of the poly(acrylic acid). The polymer blends are miscible; they retain the ability to absorb large volumes of liquids and also exhibit rubber viscoelasticity. The incorporation of glycerol reduces the glass...
Polymer nanocomposites based on poly(vinyl alcohol) (PVA)/starch blend and graphene were prepared by solution mixing and casting. Glycerol was used as a plasticizer and added in the starch dispersion. The uniform dispersion of graphene in water was achieved by using an Ultrasonicator Probe. The composites were characterized by FTIR, tensile propert...
This paper reported the effect of starch-based additive (PSN), on the rheology, morphology and thermal behavior of low-density polyethylene (LDPE). PSN was a commercial masterbatch of corn starch and linear low-density polyethylene (LLDPE) in the ratio of 45/55. Compositions of LDPE/PSN blend ratios at 100/0, 80/20, 70/30 and 60/40 were prepared by...
The present paper reports the results of studies on the effect of a prodegradant additive, named commercially as PDQ-H, on the natural weather aging in Saudi Arabia of low density polyethylene (LDPE), with special reference to the stress-strain properties, thermal behaviour, morphology and rheological properties. Incorporation of the additive cause...
Polymer nanocomposites based on polyvinyl alcohol (PVA)/starch blend and carbon nanotubes (CNT) were prepared by solution mixing, followed by casting. Glycerol was used as a plasticizer and added in the starch dispersion. The uniform dispersion of CNT in water before mixing with PVA/starch blend, was achieved by using an Ultrasonicator Probe. The c...
The method of making polyolefin with a silicon nitride nano-filler uses silicon nitride (SiN) as a promoter for in situ polymerization with a zirconocene catalyst. The method includes adding the bis(cyclopentadienyl) zirconium dichloride catalyst and nanoparticles of silicon nitride to a reactor. The reactor is then charged with toluene and a methy...
The ethylene/propylene copolymer nanocomposite is a copolymer prepared by inclusion of a filler of nanoparticles of titania doped with iron that permits control over, and variation of, the overall polymeric properties. Through the addition of the TiO2/Fe nanofiller, the concentration of polypropylene in the copolymer is increased and the overall cr...
The ethylene/propylene copolymer nanocomposite is a copolymer prepared by inclusion of a filler of nanoparticles of titania doped with iron that permits control over, and variation of, the overall polymeric properties. Through the addition of the TiO2/Fe nanofiller, the concentration of polypropylene in the copolymer is increased and the overall cr...
This article reports the results of studies on the degradation of the blend of low‐density polyethylene (LDPE) with a starch based prodegradant additive, named commercially as Polystarch plus H and abbreviated as PSH, under natural weather, underground soil aging, and sea water aging in Dhahran, Saudi Arabia. The work includes measurements of tensi...
This paper reports the results of studies on the rheological behavior of nanocomposites of high density polyethylene (HDPE) with pristine multiwall carbon nanotubes (CNT) as well as phenol and 1-octadecanol (C18) functionalized CNT at 1, 2, 3, 4, 5, and 7 wt% loading. The viscosity reduction at 1 wt% CNT follows the order, pristine CNT < phenol fun...
The method of making high-density polyethylene with titania-iron nanofillers involves mixing a TiO2/Fe titania-iron nanofiller with a vanadium (III) complex bearing salicylaldiminato ligands polymerization catalyst in a reactor. The reactor is then charged with toluene and heated to a temperature of about 30° C. Following heating, ethylene is fed i...
Degradation of the blends of low‐density polyethylene (LDPE) with a starch‐based additive namely, polystarch N was studied under various environmental conditions such as natural weather, soil and sea water in Saudi Arabia. Stress–strain properties and thermal behavior were investigated for the LDPE and LDPE/polystarch N blend having 40% (w/w) of po...
Ethylene polymerization was done to form polyethylene nano-composite with nanoaluminum nitride using zirconocene catalysts. Results show that the catalytic activity is maximum at a filler loading of 15 mg nanoaluminum nitride. Differential scanning calorimeter (DSC) and X-ray diffraction (XRD) results show that percentage crystallinity was also mar...
The present paper reports the results of studies on the effect of laser irradiation on the morphology and thermal properties of starch/polyvinyl alcohol (PVA) blend, with varying glycerol concentration. Differential scanning calorimeter results showed that laser irradiation increased the heat of fusion (ΔHfus), heat of crystallization (ΔHcry), temp...
Starch plasticized with glycerol and blended with polyvinyl alcohol (PVA) is recommended for use as a biodegradable material. The present article reports the results of studies of the natural weather ageing of starch/PVA blends having various amounts of glycerol in natural weather conditions of Saudi Arabia, with special reference to morphology and...
Low density polyethylene nanocomposites filled with carbon nanotubes (CNT) having three different aspect
ratios have been prepared by melt mixing technique. The effects of CNT loading, its aspect ratio, and frequency of electric field on electrical and dielectric properties of the nanocomposites have been investigated. DC and AC electrical resistiv...
Humans have been exposed to airborne nanosized materials (<100 nm) throughout the millennia, but the extent of exposure has increased significantly since the industrial revolution with special reference to the combustion processes. The advent of nanotechnology in the last 2 decades has further increased the risk of exposure of nanomaterials through...
Blends of low‐density polyethylene (LDPE) with Polystarch N were prepared by extrusion. Tensile properties, thermal behavior, and natural weathering of these blends were investigated as a function of blend composition. The addition of Polystarch N to the matrix decreased the tensile properties and the degree of crystallinity of LDPE when the propor...
The article reports the results of the studies on the effect of nano-titanium dioxide (TiO2) on the morphology, thermal, and mechanical properties of 1:1 starch/polyvinyl alcohol (PVA) composites. Degree of crystallinity of the starch/PVA blends increases with increase in the amount of nano-TiO2 as determined by differential scanning calorimeter an...
Compatibility of starch/polyvinyl alcohol (PVA) blends, prepared by solution cast method, is dependent on the blend composition. Crystallinity of the blend, as measured by X-ray diffraction (XRD) and differential scanning calorimeter (DSC), decreases with increase in starch content. Thermogravimetric analysis (TGA) shows that the broadness in the p...
This article reports the rheological behavior of nanocomposites of isotactic polypropylene with both unmodified multiwall carbon nanotubes (CNTs) and phenol and 1-octadecanol (C18) functionalized CNT (f-CNT) at 0.1, 0.25, 1.0, and 5.0 wt% of the nanofillers. The incorporation of CNT at low loadings of 0.1 and 0.25 wt% decreases the storage and loss...
Ethylene polymerization was carried out using highly active metallocene catalysts (Cp2ZrCl2 and Cp2TiCl2) in combination with methylalumoxane. Titanium(IV) oxide containing 1% Mn as dopant was used as nanofillers. The influence of filler concentration, reaction temperature and pressure on the catalytic activity and polymer properties was investigat...
Recent attempts toward improving the properties of natural rubber (NR) by using carbon nanotubes (CNT) as filler were not successful due to low dispersion of CNT in NR. This article reports the results of studies on improvement of dispersion of CNT in NR by acid modification of CNT surface. Fourier transform infrared spectra confirmed the presence...
This article reports the results of studies on the effect of 1-octadecanol (abbreviated as C18) functionali-zation of carbon nanotubes (CNT) on electrical properties of natural rubber (NR) composites. Dispersion of CNT in NR matrix was studied by transmission electron micros-copy (TEM) and electrical resistivity measurements. Fou-rier transform inf...
Multi-walled carbon nanotubes (CNTs) were functionalized on treatment with nitric acid and the surface-modified CNT was characterized using Fourier transform infrared spectroscopy (FTIR). Isotactic polypropylene (iPP)/CNT composites at different CNT loadings (i.e., 0.1, 0.25, 1.00, and 5.00 wt%) were prepared by melt blending in a mini blender. The...
This paper reports the results of studies on the effect of phenol functionalization of carbon nanotubes (CNTs) on the mechanical and dynamic mechanical properties of natural rubber (NR) composites. Fourier transform infrared spectrometry (FTIR) indicates characteristic peaks for ether and aromatic rings in the case of phenol functionalized CNT. Alt...
In this work, multiwall carbon nanotubes (MWCNT) were functionalized with phenol and characterized by using Fourier transform infrared spectroscopy (FTIR). Isotactic polypropylene (iPP)/MWCNT composites of both the unfunctionalized and functionalized MWCNT were prepared by melt blending in a miniextruder at different loadings of nanotubes (i.e., 0....
An easy one pot method is demonstrated for the controlled periodical surface coating of polyethylene over multiwalled carbon nanotubes (MWCNT) by insitu polymerization of ethylene using highly active metallocene catalysts (Cp2ZrCl2 and Cp2TiCl2) in combination with methylalumoxane. The crystallinity of the nanocomposite was increased and its morpho...
The paper reports the results of studies on the effect of glycerol content on thermal, mechanical, and dynamic mechanical properties of blends of starch and polyvinyl alcohol (PVA). Degree of crystallinity of the starch/PVA blends (4 g/4 g ratio) remains almost constant up to 3.78 g of glycerol as determined by differential scanning calorimetry (DS...
Thermoplastic elastomeric blends of nitrile rubber (NBR)/poly(styrene-co-acrylonitrile) (SAN) and NBR/scrap computer plastics (SCP) based on acrylonitrile-butadiene-styrene terpoly-mer (ABS) were prepared. Thermoplas-tic elastomeric blends of NBR/SAN containing various amounts of a model waste nitrile rubber powder (w-NBR) were also prepared. Therm...
The incorporation of small amount of ionic groups into hydrocarbon polymers results in unique physical properties and these polymers are called ionomers. They are effectively cross-linked through the association of ionic groups, forming multiplets or clusters. These associations are thermally labile to a greater or lesser extent depending on the co...
Atomic force microscopic (AFM) studies on the 50/50 blend of silicone rubber and fluororubber based on tetrafluoroethylene-propylene-vinylidene fluoride terpolymer reveal that the morphological features do not undergo appreciable change on 50% replacement of the fluororubber in the blend by its vulcanizate powder of fine particle size (1 mm). On th...
The present paper reports the results of studies on the thermorheological properties and extrudate characteristics of the 60/40, 70/30 and 80/20 nitrile rubber (NBR)/poly(styrene-co-acryloni-trile) (SAN) blends. The effects of dynamic vulcanization and replacement of a part of the virgin NBR by a nitrile rubber vulcanizate powder (w-NBR) on the 70/...
The paper reports that the processing behavior and physical properties of the blends of silicone rubber and fluororubber based on tetrafluoroethylene/propylene/vinylidene terpolymer. The processing behavior of the fluororubber can be improved on blending with low viscous silicone rubber. The results indicate that the processing behavior, mechanical...
This paper reviews the utilization of waste rubber and waste plastics for the preparation of thermoplastic elastomers (TPEs). TPEs based on ground rubber tire (GRT), waste EPDM rubber, waste nitrile rubber, recycled rubber, latex waste, and waste plastics are described with respect to composition and physical properties. It is found that part of th...
A model waste nitrile rubber powder (w-NBR) was prepared by ambient grinding of aged NBR vulcanizate based on an oil seal formulation. The w-NBR was characterized by scanning electron microscopic and optical microscopic techniques. Virgin nitrile rubber in a thermoplastic elastomeric 70:30 nitrile rubber/poly(styrene-co-acrylonitrile) (SAN) blend w...
Acrylonitrile-butadiene-styrene terpolymer (ABS) is one of the engineering plastics most frequently used as outer casings for computer equipment such as monitors, keyboards and other similar components. In an attempt to recycle, blends of scrap computer plastics (SCP) based on ABS with nitrile rubber (NBR) were prepared and mechanical properties an...
Thermorheological properties of thermoplastic elastomeric 60/40, 70/30 and 80/20 nitrile rubber (NBR)/scrap computer plastics (SCP) blends were studied by using parallel plate rheometer. The blends exhibit pseudoplasticity and obey power law model. The dynamically vulcanised blends have higher dynamic viscosities than their unvulcanised counterpart...
This article reports the development of a new composite based on acrylonitrile butadiene rubber (NBR) and melamine fiber. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) have been used to study the effect of a dry bonding system in improving the adhesion between the fiber and the matrix. Mechanical properties of the composites...
This article reports the development of new composites based on maleated ethylene–propylene–diene monomer (EPDM) rubber and melamine fiber. The compositions are cured using three different types of curing systems: conventional covalent crosslinking based on sulfur and an accelerator, fully ionic crosslinking based on zinc oxide/zinc stearate, and m...
Dynamically vulcanized thermoplastic elastomeric blends of nitrile rubber (NBR)/poly(styrene-co-acrylonitrile) (SAN) were mapped by tapping mode atomic force microscopy (TMAFM) and transmission electron microscopy (TEM). The morphology changes with the blend ratio and dynamic vulcanization. Roughness and surface analysis were used to study the effe...
While silicone rubber has a much lower shear viscosity than that of fluororubber, the viscosity of silicone rubber/fluororubber blends is closer to that of silicone rubber. All rubber compositions show pseudoplastic behavior. While the viscosity of a 50/50 silicone rubber/fluororubber blend increases on replacement of the silicone rubber by silicon...
The effects of dynamic vulcanization and blend ratios on mechanical properties and morphology of thermoplastic elastomeric (TPE) compositions, based on blends of nitrile rubber (NBR) and poly(styrene-co-acrylonitrile) (SAN), were studied. The TPE composition prepared by adding a rubber-curatives masterbatch to softened SAN yields higher mechanical...
The rheological behavior of ethylene propylene diene monomer (EPDM) compounds containing ground EPDM waste (W-EPDM) of known composition was studied by using a Monsanto processability tester in a temperature range of 90–110°C and a shear rate range of 306.7–1533.24 s−1. It is found that the shear viscosity decreases slightly with increasing W-EPDM...
The use of powdered factory scraps in EPDM compounds is discussed. It is found that the powdered rubber obtained by the abrasion technique is highly aggregated but the particle are ultra-fine with a rough, convoluted surface. The breakdown of aggregates of powdered rubber and homogeneous dispersion of the particle in the rubber matrix are also elab...
It is evident from Monsanto rheometric studies, dynamic mechanical analysis (DMA), physical property measurements and scanning electron microscopy (SEM) that the mixer rotor speed has an effect on the crosslinking of poly(acrylic acid) (PAA)/epoxidized natural rubber (ENR) blends. These studies reveal that mixing at high rotor speed deteriorates th...
This paper reports the results of studies on the thermal and ablative properties of the vulcanizates based on EPDM, maleated EPDM and nitrile rubber reinforced with melamine fibre, one of the recent generation high performance fibres. The thermogravimetric studies of the composites show that the presence of melamine fibre in the vulcanizates reduce...
This paper reports the results of Atomic Force Microscopic (AFM) studies on blends of silicone rubber and fluororubber based on tetrafluoroethylene/propylene/vinylidene fluoride terpolymer. The surface morphology of the single component rubbers and their blends and the effect of the blend ratio on the surface morphology were studied using analysis...
Processability, curing characteristics and vulcanizate properties of EPDM compounds containing ground waste EPDM (W-EPDM) have been studied. Ground waste was prepared from factory scraps, using a mechanical grinder with silicon carbide abrasive wheel rotating at 2950 rpm. The particle size shows a range between 2 and 50 mum, with an average size of...
The paper reports the results of Limiting oxygen index (LOI) measurements, thermogravimetric (TG) analysis and hot oil resistance (ASTM #1 and IRM 903 oils both at 150 °C) of silicone rubber, fluororubber based on tetrafluoroethylene/propylene/vinylidene fluoride terpolymer and their blends. Fluorosilicone rubber is included in the studies as a con...
The silicone rubber vulcanizate powder (SVP) obtained from silicone rubber by mechanical grinding exists in a highly aggregated state. The particle size distribution of SVP is broad, ranging from 2 µm to 110 µm with an average particle size of 33 µm. X-ray Photoelectron Spectroscopy (XPS) and Infrared (IR) Spectroscopy studies show that there is no...
Fluororubber vulcanizate powder (FVP) obtained from fluororubber based on tetrafluoroethylene/propylene/vinylidene fluoride terpolymer by mechanical grinding exists in a highly aggregated chain-like structure. X-ray photoelectron spectros-copy (XPS) and infrared (IR) spectroscopy studies show that there are no chemical change on the rubber surface...
The melt flow properties of unfilled and filled brominated isobutylene-co-paramethylstyrene (BIMS) were measured by means of a capillary viscometer at three different temperatures (90°C, 110°C and 130°C) and four different shear rates (61, 122, 245 and 306 s−1). The effect of addition of EPDM rubber on melt flow properties of unfilled BIMS was also...
The vulcanization process of powdered natural rubber is discussed with special focus on utilization of waste rubber products. The abrasion technique was used for obtaining ultra-fine powder. It was found that the vulcanizate powder can be used as a cheap filler in virgin rubber compounds without adversely affecting the final vulcanizate properties....
The thermorheological behaviour of thermoplastic elastomeric blends based on both ground rubber tyre (GRT) and maleic anhydride grafted GRT (m-GRT) has been studied. The blend composition based on m-GRT exhibits a higher melt viscosity than the corresponding control blend based on GRT. The former exhibits lower die swell and less melt fracture at l...
The milling behavior of brominated isobutylene-co-paramethylstyrene (BIMS), ethylene propylene diene terpolymer (EPDM), and their blends was investigated over a range of temperatures and friction ratios using the continuous milling operation. At 30 °C, BIMS forms a loose nervy appearance and, as the temperature is increased to 90 °C, it gradually f...
Melamine fibre is a new category of advanced synthetic fiber having superior heat and flame resistance with decomposition temperature above 350°C. It suitability as a reinforcing fiber for ethylene propylene diene terpolymer, abbreviated as EPDM rubber, where ‘M’ stands for polymethylene chain, was investigated. It has been observed that tensile st...
Oxygen containing chemical groups on the carbon black surface can react with the carboxyl groups of XNBR. or epoxy groups of ENR. or chlorosulfonated groups of CSM, during high temperature molding of the rubber-filler mixtures. This leads to crosslinking of the rubber phase. The extent of crosslinking increases if the carbon black surface is oxidiz...
Dielectric analysis (DEA) of molded ground waste rubber tire (GRT) and its chlorinated derivatives (Cl-GRT) was undertaken. Dielectric spectra of Cl-GRT show formation of a biphasic structure consisting of the rubbery phase and a hard phase whose relaxation occurs in the high-temperature region. DEA of plasticized poly(vinyl chloride) (PVC) contain...
The processability, curing characteristics, and mechanical properties of a window seal compound based on highly filled and oil extended EPDM rubber (R-EPDM) containing ground EPDM vulcanisate of known composition (W-EPDM) simulating the waste window seal product have been studied. A conventional mechanical grinder with a rotating abrasive wheel was...
Chlorinated ground rubber tire (Cl-GRT) particles were used as filler in a plasticized polyvinylchloride (PVC) to develop a melt-processable rubber composition. Physical properties of the Cl-GRT-filled PVC compound showed improvement compared to the nonchlorinated counterpart. Interaction between Cl-GRT and PVC was examined on the basis of results...
Ground rubber tire (GRT) powder was maleated in an internal mixer using maleic anhydride and dicumyl peroxide at 160°C. Maleated GRT was characterized by using X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, wettability, and differential scanning calorimetry. The physical properties of the dynamically vulcanized 60 : 40,...
Ground rubber tire (GRT) and its chlorinated derivative (CI-GRT) were filled in a plasticized polyvinylchloride (PVC) compound. Thermorheological studies of the PVC compound and its blends with GRT and CI-GRT were done using a shear dynamic oscillating rheometer. Rheological complexity of the compositions was analyzed from double logarithmic plot o...
This paper reports the characterization of unaged and aged melamine fibers using various characterization techniques including atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermal analysis. Since melamine fiber is a relatively new fiber, very few studies on it...
Virgin ethylene propylene diene monomer (EPDM) rubber in a thermoplastic elastomeric blend of polypropylene (PP) and EPDM rubber was substituted by ground EPDM vulcanizate of known composition, after which the mechanical properties of the raw EPDM/waste EPDM/PP blends were determined. The ratio of the rubber content in the waste EPDM (r-W-EPDM) to...
Processing, cure characteristics, and mechanical properties of EPDM rubber containing ground EPDM vulcanizate of known composition were studied. Mooney viscosity increases and Mooney scorch time decreases by the addition of the ground vulcanizate. At higher loadings of the ground rubber, the maximum rheometric torque decreases. On addition of groun...
Milling behavior of brominated isobutylene-co-paramethylstyrene (BIMS), and its blends with ethylene propylene diene rubber (EPDM), with special reference to the effect of addition of different fillers, filler loadings and processing oil, was investigated over a range of temperatures in a drop mill operation. The critical nip gap (CNG, at which a f...
This study reports the results of investigations on blends of silicone rubber and fluororubber based on tetrafluoroethylene/propylene/vinylidene fluoride terpolymer and the effects of replacement of silicone rubber and/or fluororubber in their 50/50 blend by the respective vulcanizate powders of known compositions. To simulate the aging condition o...
Milling behavior of brominated isobutylene-co-paramethylstyrene (BIMS) and its blends with ethylene propylene diene terpolymer (EPDM) rubber, was investigated over a range of temperatures and friction ratios in a drop mill operation. BIMS showed striking changes, that is, from a loose nervy band to a tight elastic band, as the temperature of the ro...
Dielectric studies show that the blends of silicone rubber and fluororubber based on tetrafluoroethylene/propylene/vinylidene fluoride terpolymer are immiscible. Dielectric loss factor at any temperature increases with increase in concentration of the fluororubber phase in the blend composition. The activation energy of the relaxation of the vinyli...
Novel block copolymer ionomers having both carboxylate and sulfonate groups in the same polymer backbone were obtained by sulfonating maleated poly (styrene-(ethylene-co-butylene)-styrene) block copolymer (m-SEBS), followed by its neutralization with barium acetate. The effects of the degree of neutralization on the properties of the ionomers were...
Ground rubber tire (GRT) powders were chlorinated by trichloroisocyanuric acid (TCLCA). GRT powders of different chlorination levels were characterized by X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDAX), attenuated total reflection infrared (ATR-IR) spectroscopy, thermal, dielectric, and stress-strain properties...
Chlorosulfonated polyethylene (CSM) reacts with aluminum oxide in the presence of stearic acid producing an ionic elastomer. Although CSM cannot be cross linked with dicumyl peroxide (DCP) alone, DCP crosslinking can be achieved in the presence of aluminum oxide and stearic acid. Moving die rheometric (MDR) studies show the occurrence of a two-stag...
Blends of two or more polymers having appropriate reactive groups can be crosslinked through condensation or substitution reactions in the absence of crosslinking chemicals when molded at high temperatures for prolonged times. When at least one of the two polymers is a rubber, such blends are called "self-crosslinking rubber blends." Self-crosslink...