Effect of Sulfur during Radiation Curing of Poly(Vinyl Ethyl Ether) and Ethylene-Propylene Rubber

1963 ◽  
Vol 36 (1) ◽  
pp. 248-258 ◽  
Author(s):  
Joginder Lal ◽  
James E. McGrath
Keyword(s):  
Tensile Strength ◽  
Ethyl Ether ◽  
Triphenyl Phosphine ◽  
Radiation Curing ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
Maximum Tensile Strength ◽  
Lower Radiation Dose ◽  
Ethylene Propylene Rubber ◽  
Sulfur Containing

Abstract A study was made of the effect of sulfur, during radiation curing, on the physical properties of poly(vinyl ethyl ether) and an ethylene/propylene copolymer containing HAF carbon black. The presence of sulfur enabled the attainment of higher maximum tensile strength and generally higher crosslink density than when sulfur was omitted. Furthermore, the maximum tensile strength of the sulfur-containing samples was obtained at a lower radiation dose than in the corresponding control experiments. For a given swelling ratio, a higher tensile strength was generally obtained for samples irradiated in the presence of sulfur. For a given dose of radiation, the per cent elongation-at-break values of poly(vinyl ethyl ether) samples decreased as the amount of sulfur in the recipe was increased. In contrast, in the ethylene/propylene rubber the presence of sulfur resulted in an increase in the elongation values. The per cent sol values were also quite high for the ethylene/propylene vulcanizates as compared to the corresponding values in poly(vinyl ethyl ether) samples. In both rubbers, lower sol values were obtained in the presence of sulfur. Chemically bound sulfur was found in poly(vinyl ethyl ether) samples irradiated in the presence of elemental sulfur or dicyclopentamethylene thiuram tetrasulfide. The ability of the network to lose a portion of the combined sulfur by reaction with triphenyl phosphine may indicate that some of the crosslinks contain disulfide and/or polysulfide groups.

Influence of Vulcanizing System on the Properties of Rubbers Based on Ethylenepropylene Rubber

2021 ◽  
Vol 899 ◽  
pp. 239-244
Author(s):  
Larisa Yuryevna Zakirova
Keyword(s):  
Tensile Strength ◽  
High Temperatures ◽  
Organic Peroxide ◽  
Strength Properties ◽  
Maximum Speed ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
Rubber Compounds ◽  
Ethylene Propylene Rubber ◽  
Aging In Air

The article investigates the effect of vulcanizing systems of different activity on the vulcanization and elastic-strength properties of rubber compounds based on ethylene-propylene rubber Keltan . Were taken vulcanizing systems: a mixture of organic peroxide, sulfur and sulfenamide accelerator (1); a mixture of organic peroxide, sulfur and dithiodimorpholine (2); a mixture of organic peroxide, sulfur and thiuram accelerator (3); sulfur and sulfenamide accelerator (4). The vulcanization characteristics (maximum and minimum torques; times of onset, optimum and reaching the maximum speed of vulcanization) were evaluated. Elastic-strength (conditional tensile strength, elongation at break, hardness) properties of rubber compounds and operational (changes in conditional tensile strength, elongation at break after aging in air) were determined. It was found that the vulcanizing system (3) containing sulfur, peroxide in an amount of 7.0 parts by weight and thiuram accelerator imparts the best elastic and strength properties to rubber compounds and leads to their resistance to high temperatures.

Peroxide Crosslinking of Ethylene-Propylene Rubber

1965 ◽  
Vol 38 (1) ◽  
pp. 22-32 ◽  
Author(s):  
L. D. Loan
Keyword(s):  
Tensile Strength ◽  
Hydrogen Atom ◽  
Stress Relaxation ◽  
Ethylene Propylene ◽  
Permanent Set ◽  
Ethylene Propylene Rubber ◽  
Crosslinking Reactions ◽  
Allyl Compounds ◽  
Sulfur Containing ◽  
Peroxide Molecule

Abstract The crosslinking of ethylene-propylene rubber by means of cumyl peroxide has been followed in detail. The overall crosslinking efficiency has been found to be about 0.4 crosslinks per peroxide molecule, and this result has been shown by stress relaxation and permanent set experiments to result from a mixture of both scission and crosslinking reactions. The results obtained with two different rubbers are consistent with the view that scission results from abstraction of a tertiary hydrogen atom while crosslinking arises from attack at a secondary hydrogen. Such a scheme allows a relative reactivity of tertiary:secondary of 6:1 to be calculated. The action of sulfur in peroxide cures has been shown to be to introduce labile, presumably sulfur-containing, crosslinks. Such labile crosslinks explain the increased tensile strength of such vulcanizates. Allyl compounds are effective in increasing the crosslinking efficiency of the peroxide.

scholarly journals The influence of functional ingredients on the physico-mechanical and operational properties of rubbers for water-swelling sealing elements

2019 ◽  
Vol 58 (6) ◽  
pp. 152-157
Author(s):  
Evgeny N. Egorov ◽  
◽  
Nikolay F. Ushmarin ◽  
Konstantin V. Efimov ◽  
Sergey I. Sandalov ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Weight Changes ◽  
Gas Industry ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
Water Swelling ◽  
Methyl Styrene ◽  
Sealing Elements

The article investigated the effect of caoutchoucs, sevilen 11808-340, vulcanizing groups, fillers, plasticizers, directional ingredients on the physicomechanical (conditional tensile strength, elongation at break, hardness, rebound elasticity, tear resistance) and operational properties of two rubbers (changes of conditional tensile strength of rubbers after exposure to water, weight changes after aging of rubbers in a solution of citric and hydrochloric acids, changes in the volume of rubbers after exposure to water). These rubbers are developed for the manufacture of the outer and inner layers of water-swelling sealing elements (WSSE) for the oil and gas industry. It has been established that rubber for the outer layer of WSSE based on butadiene-nitrile BNKS-18AMN, isoprene SKI-3 and ethylene-propylene SKEPT-40 caoutchoucs, as well as rubber for the inner layer of WSSE based on butadiene-nitrile BNKS-18AMN, butadiene-methyl styrene SKMS-30AR and ethylene-propylene SKEPT-40 caoutchocs possess the required physical-mechanical and operational properties. It was shown that these rubbers containing a vulcanizing group sulfur + thiazole 2 MBS, sevilen 11808-340, a combination of carbon black T 900 with rosil 175, talc and Karelite MK, petroleum resin “Sibplast”, vermiculite and igloprobivnoe cloth, a combination of hydrosorbtional polyacrylamide 639, sodium polyacrylate, perlite and Kometa-R reagent are characterized by improved physicomechanical and operational properties. These rubbers can be recommended as the basis for the manufacture of the outer and inner layers of water-swellable sealing elements.

Ultrafine Wollastonite Reinforced Polypropylene/Ethylene Propylene Diene Rubber Thermoplastic Elastomers

2012 ◽  
Vol 488-489 ◽  
pp. 945-949 ◽  
Author(s):  
Saowaroj Chuayjuljit ◽  
Thatisorn Karnjanamayul
Keyword(s):  
Thermal Stability ◽  
Tensile Strength ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Thermoplastic Elastomers ◽  
Dependent Manner ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
Ethylene Propylene Diene Rubber ◽  
Diene Rubber

In this study, tensile properties, thermal stability and morphology of polypropylene/ethylene propylene diene rubber/wollastonite (PP/EPDM/wollastonite) thermoplastic elastomer composites were tested and evaluated as a function of their compositions in comparison with PP/EPDM blends and native PP. PP was melt mixed with two loadings of EPDM (20 and 30% (w/w)) and for the composites each of these with three loadings of wollastonite (10, 20 and 30 parts by weight per hundred of the PP/EPDM resin) on a twin screw extruder and then injection molded. Both PP/EPDM blends provided a higher elongation at break but a lower tensile strength and Young’s modulus as compared with those of the neat PP. However, the addition of wollastonite microparticles (particle size of 1200 mesh) into the blends increased the Young’s modulus in a dose-dependent manner with increasing wollastonite loadings, whilst the tensile strength and elongation at break were decreased. Moreover, the thermal stability was improved by the presence of either EPDM or wollastonite in the PP matrix.

Effect Maleic Anhydride Polypropylene on Properties of Calcium Carbonate Filled Polypropylene/Ethylene Propylene Diene Terpolymer Composites

2013 ◽  
Vol 594-595 ◽  
pp. 770-774 ◽  
Author(s):  
Husseinsyah Salmah ◽  
A. Siti Rohana ◽  
Hussin Kamarudin
Keyword(s):  
Tensile Strength ◽  
Calcium Carbonate ◽  
Maleic Anhydride ◽  
Modulus Of Elasticity ◽  
Sem Analysis ◽  
Inorganic Filler ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
The Matrix ◽  
Ethylene Propylene Diene Terpolymer

Inorganic filler, calcium carbonate (CaCO3) was used as filler in the polypropylene (PP)/ ethylene propylene diene terpolymer (EPDM) composites. The composites were compatibilized with Maleic anhydride grafted polypropylene (MAPP) in order to improve the properties. The addition of CaCO3 at has increased the modulus of elasticity of composites but tensile strength and elongation at break of uncompatibilized composites decreased with increasing CaCO3. The result shows that the compatibilized composites higher tensile strength and Modulus of elasticity but lower elongation at break compared to uncompatibilized composites. At 10 wt% CaCO3 showed higher tensile strength of uncompatibiled and compatibilized composites. The morphology study from SEM analysis reveals that compatibilized composites show better interfacial adhesion between the filler and the matrix. The addition of MAPP has improved crystallinity of compatibilized composites.

scholarly journals The Study of Recycled Ethylene Propylene Diene Monomer (EPDM-r)/Polypropylene (PP) Polymeric Blends

2021 ◽  
Vol 2080 (1) ◽  
pp. 012012
Author(s):  
MH Zulkifli ◽  
MSM Rasidi ◽  
NAM Rahim ◽  
L Musa ◽  
Abdul Hakim Masa
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Young’S Modulus ◽  
Morphological Study ◽  
Young's Modulus ◽  
Tensile Tests ◽  
Ethylene Propylene Diene Monomer ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
Polymeric Blends

Abstract In this study, recycled ethylene propylene diene monomer (EPDM-r) were blended with polypropylene (PP) by compounding via heated two roll mills with the various ratio of EPDM-r. Certain blends were included with PP-g-MA as a compatibilizer. In tensile tests, the increasing of EPDM-r content in blends resulted in the reduction of tensile strength and Young’s Modulus but increased elongation at break. Furthermore, the presence of compatibilizer in blends enhanced the tensile properties. It was found all the samples with compatibilizer performs better results in tensile strength, Young’s Modulus, and elongation at break than samples without compatibilizer. On the other hand, the aging affected were studied on compatibilized and uncompatibilized blends. It was found that aging affects the samples by decreasing the tensile strength, Young’s Modulus, and elongation at break. The crosslink density had been found higher in the blends with high EPDM-r content as the EPDM-r had the ability to swell. The morphological study related to the structure with the tensile properties. It was confirmed that the presence of a compatibilizer increased the compatibility between EPDM-r and PP matrix.

Tensile Properties and Melt Flow Index of Polypropylene/Ethylene Propylene Diene Monomer Nanocomposites

2015 ◽  
Vol 1107 ◽  
pp. 125-130 ◽  
Author(s):  
Muhammad Safwan Hamzah ◽  
M. Mariatti ◽  
M. Kamarol
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Melt Flow Index ◽  
Filler Loading ◽  
Flow Index ◽  
Ethylene Propylene Diene Monomer ◽  
Melt Flow ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
Internal Mixer

In this article, we report three nanofillers filled polymer composite systems. Nanofillers composed of alumina, titania and organoclay were embedded separately in 50% polypropylene (PP) and 50% ethylene propylene diene monomer (EPDM) blends. The nanocomposites were prepared using an internal mixer and were molded using a compression mold to form test samples. Effect of filler loading (2, 4, 6, and 8 vol.%) on the tensile properties and melt flow index (MFI) were determined. The mechanical properties of alumina are the highest compared to titania and organoclay. Alumina and organoclay shows an ascending trend in tensile strength with the increase of nanofiller loading. In contrast, the increment of titania filler loading reduces the tensile strength of the nanocomposites. The Young's modulus of the nanocomposites increases with the addition of filler loading. Elongation at break of the nanocomposites shows a descending trend with the addition of filler loading. The addition of 8 vol. % titania and organoclay slightly changes the MFI of the PP/EPDM nanocomposites whereas the addition of 8 vol. % alumina drastically decreased the MFI values. Further addition of nanofillers up to 8 vol. % decreases the MFI values of the PP/EPDM nanocomposites.

scholarly journals Life assessment of marine ethylene propylene rubber power cables based on hardness retention rate

2017 ◽  
Vol 66 (3) ◽  
pp. 475-484 ◽  
Author(s):  
Xiaokai Meng ◽  
Zhiqiang Wang ◽  
Guofeng Li
Keyword(s):  
Evaluation Method ◽  
Retention Rate ◽  
Condition Assessment ◽  
Life Assessment ◽  
Power Cables ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
Ethylene Propylene Rubber ◽  
Different Temperatures ◽  
Insulation Condition

AbstractThe lifetime of ethylene propylene rubber (EPR) insulated cables will decrease because of complex aging processes. From the safety perspective, insulation condition assessment of the cable is essential to maintain an efficient and reliable operation. As a nondestructive and online evaluation method, a hardness retention rate was used to estimate the lifetime of cable. First, accelerated thermal aging tests in the laboratory were performed to measure the elongation at break retention rate (EAB%) and a hardness retention rate at different temperatures. Second, the aging values were processed by the Arrhenius equation and time temperature superposition to assess aging lifetime of insulation at different temperatures and end levels. As the insulation condition assessment of the cable by hardness retention test has no approved standard, the EAB% data were correlated with hardness retention to provide an evaluation basis. The results show that when EAB% picks out the time corresponding to a certain amount of 50% degradation, 10% of hardness retention was chosen as the termination index.

scholarly journals The influence of technological additives and peroxides on the properties of rubber mixtures based on ethylene propylene caoutchouc

2019 ◽  
Vol 60 (10) ◽  
pp. 81-87
Author(s):  
Nikolay F. Ushmarin ◽  
◽  
Lyudmila Yu. Tsareva ◽  
Ksenia A. Konnova ◽  
Maria V. Yakimova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Tensile Elongation ◽  
Physical And Mechanical Properties ◽  
Physicomechanical Properties ◽  
Dicumyl Peroxide ◽  
Rubber Mixture ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
Aging In Air

The article investigates the influence of technological additives and peroxides on the properties of two rubber mixtures based on ethylene-propylene caoutchouc of marking SKEPT-40. The main properties were: rheometric (maximum and minimum torques; start, optimum and maximum vulcanization rates; maximum vulcanization rates), physical and mechanical (conditional tensile strength, elongation at break, hardness) and operational (changes in conditional strength at tensile, elongation at break and hardness after aging in air). The resistance of rubbers to the action of high temperatures by methods of differential thermal and thermogravimetric analysis was studied. As technological additives, MA-L22, Struktol WS180, Zincolet BB 222 and Struktol A89 were used. Vulcanizing agents were peroxides: Novoperox BP-40, Percodox BC-FF, Dicumyl Peroxide (DK), Chemanox PX1 and Dicumyl Peroxide DCP 99. The studies were carried out for two rubbers, one of which is intended for the manufacture of molded products, and the second rubber – for sealing profiles. It was shown that the technological additive Zincolet BB 222 increases the vulcanization rate of rubber mixture for molded products. All technological additives used have practically no effect on the conditional tensile strength and hardness vulcanizates of molded products, increasing their elongation at break. The smallest changes in the physical and mechanical properties are characterized by the vulcanizate, which contains the technological additive Zincolet BB 222. Technological additives practically do not affect the process of vulcanization of the rubber mixture and slightly affect the process of destruction of rubber during aging. Of the investigated technological additives Zincolet BB 222 is more conducive to improving the thermal properties of rubber. It has been established that Novoperox BP-40 and Chemanox PX1 peroxides increase the rate of vulcanization of the rubber mixture for sealing profiles. For vulcanizates of this rubber mixture, when Novoperox BP-40 and Chemanox PX1 is replaced with other peroxides, a decrease in the conditional tensile strength, hardness and an increase in the elongation at break are observed. With aging in air, changes in the physicomechanical properties of the vulcanizates of the rubber mixture variants containing Novoperox BP-40 and Chemanox PX1 are insignificant and close to each other.

The Influence of CB, Silica and CaCO3 on Tensile and Morphological Properties of vPE/rPE/EPDM Blends

2013 ◽  
Vol 594-595 ◽  
pp. 808-811
Author(s):  
Hanafi Ismail ◽  
N.Z. Noimam ◽  
Woon Hon Wei ◽  
Muhammad Ridhwan Jamalul Nasir
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Tensile Properties ◽  
Morphological Properties ◽  
Elongation At Break ◽  
Ethylene Propylene ◽  
Recycled Polyethylene ◽  
Ethylene Propylene Diene Terpolymer ◽  
Scanning Electron

The virgin polyethylene (vPE) and recycled polyethylene (rPE) was melt blended with ethylene propylene diene terpolymer (EPDM) in different ratio by using a Haake Rheomix at 180°C and 50 rpm were prepared. The characterization such as tensile properties and morphology were examined. Results indicated that, the tensile strength and youngs modulus of vPE/rPE/EPDM with CB show the highest value compared to silica and CaCO3 except for elongation at break. The scanning electron microscopy (SEM) studies proved that, better dispersion and less agglomeration of CB and silica filled particles as compared to the CaCO3.

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