Effect of gamma irradiation on ethylene propylene diene terpolymer rubber composites (original) (raw)
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Tensile failure of γ-ray irradiated blends of high-density polyethylene and natural rubber
Journal of Applied Polymer Science, 1986
The effect of 6oCo y-radiation on the tensile properties of thermoplastic elastomer blends of natural rubber (NR) and high-density polyethylene (HDPE) has been investigated. The samples were irradiated to absorbed doses ranging from 0.1 to 100 Mrad in air at room temperature (25°C) a t a dose rate of 0.21 Mrad/hr. The effect of blend ratio and addition of carbon black (N 330) dicumyl peroxide (DCP) on the radiation resistance of the blends has also been studied. High energy radiation at a high dose rate was found to cause extensive crosslinking in the bulk, which in effect, caused a minima in the ultimate tensile strength in the range of 10-25 Mrad and a continuous decline in the elongation a t break in all the blends. Chain scission, on the other hand, was restricted to the surface under the above-mentioned experimental conditions. This contention was substantiated by the results of irradiation of the samples in a nitrogen environment. Scanning electron microscopy @EM) studies on the tensile fracture surface morphology of the blends have also been undertaken in order to gain insight to the mechanism of failure.
Arabian Journal of Chemistry, 2016
Gamma irradiation radical-radical interaction crosslinking of elastomers and thermoplastic is a special type of crosslinking technique that has gained importance over conventional chemical crosslinking method as process is fast, pollution free, and simple. In this work a blend polymer, based on waste polyethylene and nitrile butadiene rubber, has been irradiated with gamma-rays, mechanically and thermally investigated at varying NBR content. FTIR and SEM techniques were used in addition to the swelling behavior to emphasize the blend formation. Mechanical properties like tensile strength, elongation at break and modulus at different elongations were studied and compared with those of unirradiated ones. A relatively low-radiation dose was found effective in improving the level of mechanical properties. Differential scanning calorimeter and thermogravimetric analysis were used to study the thermal characteristics of the irradiated polymer. Enhancement in thermal stability has been observed for higher NBR containing blends and via radiation-induced crosslinking up to %50 kGy.
Gamma-Radiation Effect on Mechanical Properties of Pp / Epdm Polymeric Blends
2016
Thermoplastic elastomers (TPEs) are provided with many properties of elastomeric or rubbery materials, but can be processed with the thermoplastic processing methods; they are one of the fastest growing polymers materials which combine the elastic and mechanical properties of crosslinked rubbers with the melt processability of thermoplastics. In addition, TPEs find a lot of applications in automotive, buildings and construction, wires and cables, etc.; besides their ability to reuse and recycle the production scrap and waste. Polypropylene (Pp) is a commodity, with high melting point, high chemical resistance, low density, with a balance between physical and mechanical properties and easy processing at low cost. Nevertheless, Pp shows limitations for some special applications, in terms of impact resistance; in order to minimize this characteristic, an impact modifier, as Ethylene Propylene Diene Terpolymer (Epdm) can be used. Due to different polarity and structure between the therm...
Radiation Physics and Chemistry, 2017
Utilization of waste from tire industry as reclaimed tire rubber (RTR) by formation of blends with high density polyethylene (HDPE) is great area to be focused. Enhancement of properties by the addition of triallyl cyanurate (TAC) as a co-agent with 1, 3 and 5 % to blend of HDPE 50 weight percent and RTR 50 weight percent in presence of gamma irradiation curing were investigated. Specifically, mechanical and thermal properties were studied as a function of amount of TAC and gamma irradiation dose in range of 50-200 kGy. The resultant blends were evaluated for the values of impact strength, gel content, thermal stability, tensile properties, rheological properties and morphological properties with increasing irradiation dosage and TAC loading. The mechanical properties tensile strength, hardness, impact strength of blend containing 3% of TAC were substantially increased with increasing irradiation dosage up to 150 KGy. Rheological analysis has shown increase in viscosity with increase in TAC loading up to 3% and 150 KGy irradiation dosages. 3% loading of TAC lead to better set of properties with150 KGy gamma irradiation dosage.
Journal of Applied Polymer Science, 2014
Mechanical and thermal properties of devulcanized rubber (DR)/polypropylene (PP)/ethylene propylene diene monomer blends (EPDM) were studied at various concentrations of dicumyl peroxide (DCP) and gamma radiation doses. The blends showed improved mechanical properties for vulcanized sample. The coupling of DR/PP/EPDM with different proportions of DCP was investigated by X-ray diffraction and scanning electron microscopy techniques. Evaluation of the developed blends, unirradiated and gamma irradiated, was carried out using elastic modulus, tensile strength, elongation at break, thermogravimetric analysis, kinetic analysis, and DSC measurements.
COMPATIBILIZATION OF RUBBER BLENDS BY γ-IRRADIATION PROCESSING
normal pressure. The contribution of . In such units the cables and seals may be exposed to low rate irradiation at room temperature. Their durability is estimated at about 30 years [1]. Particular service illustrated by accidental events requires suitable behaviour under hard operation conditions. Long time duty is based on certain properties that guaranty the high performances of units. In spite of low risk of nuclear equipment for power transmission and instrumentation, evaluation of chemical stability of polymers must gain appropriate attention. Various polymer materials like monocomponent systems or blends have been checked by means of accelerated tests in order to found satisfactory formulas for products [for example, 2-5].
Chemistry & Chemical Technology
The effect of the irradiation (γ-rays or electron beam) on structure-property relationships for the high performance thermoplastic elastomers (TPEs) obtained as a result of dynamic vulcanization of the blends of recycled high-density polyethylene (HDPE), ethylene/propylene/ diene monomer (EPDM) rubber, and ground tire rubber (GTR, pre-treated with Bitumen), has been investigated. Bitumen was used as a multifunctional agent providing partial devulcanization of GTR (during GTR pre-treatment) as plasticiser and to improve adhesion between the GTR particles and surrounding thermoplastic matrix. The structure-property relationships of individual components, initial TPEs and TPEs irradiated by various doses of γ-rays or e-beam were studied using Thermogravimetric Analysis (TGA), Transmission Optical Microscopy technique, Size Exclusion Chromatography (SEC), Elementary Analysis methods, mechanical testing, etc. It was established that irradiation treatment of the studied TPEs provided significant increasing in gel fraction content. Nevertheless, a substantial decrease in gel fraction content was achieved by using α-Tocopherol (Vitamin E) as antioxidant in the TPE recipe. It was found that γirradiation treatment of HDPE/EPDM/GTR based TPEs resulted in improvement of the tensile properties thereof. A positive effect of antioxidant on tensile properties of the e-beam irradiated TPEs was observed. All the irradiated TPEs exhibited thermal behaviour similar to basic non-irradiated blends in the temperature range up to ~593 K and some improvement of stability against thermal oxidative degradation was fixed for the irradiated samples of different recipes in the temperature range of 593 to 823 K.
Journal of Applied Polymer Science, 2007
Blends of waste low-density polyethylene with waste butyl rubber of equal quantities containing reactive compatibilizing agents, namely: maliec anhydride; glycidyle methacrylate, divinyl benzene, tetraethyleneglycoldimethacrylate and diethyleneglycoldimethacrylate were prepared and exposed to different c-irradiation doses up to 400 kGy. The swelling behavior in organic solvent of the gel and soluble fractions and the degree of crosslinking were investigated. The mechanical properties, namely tensile strength and elongation at break were also studied. Thermal properties using thermo gravimetric analysis and differential scanning calorimetry analysis follow analyses have been followed up to follow the change of the structure for the irradiated and nonradiated blends. Results obtained indicated improvement in physical, mechanical and thermal properties on irradiation of the prepared blends which incorporate compatibilizing agents, but with varying degrees.
Journal of Applied Polymer Science, 2014
Scrap rubber reclamation is one of the most desirable approaches to solve the disposal problem of used tires. However, reclaimed tire rubber (RTR) has not gained enough attention due to its poor properties. In this work, the effects of poly(ethylene-covinyl acetate) (EVA) addition and electron beam (EB) irradiation on the properties of RTR were studied. The RTR/EVA blends containing 100-0 wt % of RTR were prepared in the internal mixer followed by EB irradiation with doses ranging from 50 to 200 kGy. The RTR/EVA blends were subjected to mechanical, gel content, thermal, and morphological analysis. It was found that the addition of EVA to RTR improved the mechanical properties of RTR. However, results revealed that RTR undergoes irradiation-induced crosslinking in a relatively lesser extent as compared to EVA. This observation is associated with the stabilization and radical scavenging effects of additives, which are present in the RTR matrix.
Journal of Applied Polymer Science, 2011
Linear low-density polyethylene/soya powder blends were prepared by using an internal mixer at 150 C. The soya powder content ranged from 5 to 40 wt %. Epoxidized natural rubber with 50 mol % epoxidation (ENR 50) was added as a compatibilizer. The blends were irradiated by electron beam (EB) at a constant dose of 30 kGy. The changes in gel fraction, tensile properties, morphological and thermal properties of the samples were investigated. The gel content increased after EB irradiation. However, the increment of gel content was hindered by increasing soya powder content. The tensile strength and Young's modulus of the blends were increased by EB whereas the elongation at break decreased. The tensile frac-ture surface also support the reduction of elongation at break by EB irradiation. Further analysis on the irradiated blends using Fourier transform infrared spectra indicated an increase of oxygenated product after undergoing EB irradiation. The differential scanning calorimetry result indicated that the melting temperature of the blends decreased after EB irradiation whereas the crystallinity increased. EB irradiation also enhanced the thermal stability of the blends as indicated by thermogravimetric analysis. V C 2011 Wiley Periodicals, Inc. J Appl Polym Sci 124: 5220-5228, 2012