Role of Hydroxyl-Terminated Polybutadiene in Changing Properties of EPDM/ENR Blends

2013 ◽  
Vol 844 ◽  
pp. 349-352 ◽  
Author(s):  
Sarawut Prasertsri ◽  
Passakorn Amnuay ◽  
Khanitta Sripan ◽  
Pranee Nuinu
Keyword(s):  
Thermal Aging ◽  
Crosslink Density ◽  
Aging Treatment ◽  
Elongation At Break ◽  
Compression Set ◽  
The Poor ◽  
Cure Time ◽  
Ethylene Propylene Diene Rubber ◽  
Diene Rubber

In this research, the effect of hydroxyl-terminated polybutadiene (HTPB) on processability, mechanical properties, thermal aging and oil resistance of 80/20 ethylene-propylene diene rubber/epoxidized natural rubber (EPDM/ENR) blend was investigated. The amount of HTPB used was varied from 0-4 parts per hundred of rubber (phr). The results revealed that addition of HTPB into EPDM/ENR blend decreased the compound viscosity, while scorch time and cure time slightly increased with increasing HTPB content. Furthermore, hardness, tensile and tear strengths of the blend decreased due to the poor dispersion of fillers in the presence of HTPB. After thermal aging treatment, the crosslink density of all EPDM/ENR blends increased leading to increasing in 100% modulus, tensile strength and swelling resistance, as well as reducing in elongation at break. However, it had additional plus features that high resilience with low compression set was achieved in the blend containing 2 phr of HTPB.

scholarly journals Curing and mechanical properties of chlorosulphonated polyethylene rubber blends

2011 ◽  
Vol 17 (3) ◽  
pp. 315-321 ◽  
Author(s):  
Gordana Markovic ◽  
Vojislav Jovanovic ◽  
Suzana Samarzija-Jovanovic ◽  
Milena Marinovic-Cincovic ◽  
Jaroslava Budinski-Simendic
Keyword(s):  
Mechanical Properties ◽  
Crosslink Density ◽  
Hydraulic Press ◽  
Elongation At Break ◽  
Rubber Blends ◽  
Tensile Tester ◽  
Roll Mill ◽  
Cure Time ◽  
Chlorosulphonated Polyethylene ◽  
Scanning Electron

In this paper the curing and mechanical properties of two series of prepared blends, i.e., chlorosulphonated polyethylene (CSM)/isobutylene-co-isoprene (IIR) rubber blends and chlorosulphonated polyethylene (CSM)/chlorinated isobutylene-co-isoprene (CIIR) rubber blends were carried out. Blends were prepared using a two roll-mill at a temperature of 40-50?C. The curing was assessed by using a Monsanto Oscillating Disc Rheometer R-100. The process of vulcanization accelerated sulfur of pure rubbers and their blends was carried out in an electrically heated laboratory hydraulic press under a pressure of about 4 MPa and 160?. The stress-strain experiments were performed using tensile tester machine (Zwick 1425). Results indicate that the scorch time, ts2 and optimum cure time, tc90 increase with increasing CSM content in both blends. The values of modulus at 100% and at 300% elongation and tensile strength increases with increasing CSM content, whereas elongation at break shows a decreasing trend. The enhancement in mechanical properties was supported by data of crosslink density in these samples obtained from swelling measurement and scanning electron microscopy studies of the rubber blends fractured surfaces.

Effect of Ashes as Biomass in Silica Filled Natural Rubber

2017 ◽  
Vol 735 ◽  
pp. 153-157
Author(s):  
Wasinee Pinpat ◽  
Wirunya Keawwattana ◽  
Siree Tangbunsuk
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Rice Husk Ash ◽  
Silica Content ◽  
Elongation At Break ◽  
Compression Set ◽  
Cure Time ◽  
Oil Palm Ash ◽  
Reinforcing Filler

Silica has been used as reinforcing filler in natural rubber for a period of time as it results in excellent properties for NR vulcanizes. Rice husk ash (RHA), bagasse ash (BA), and oil palm ash (OPA) obtained from agricultural wastes are mainly composed of silica in the percentage of 80.00%, 57.33%, and 40.20% by weight, respectively. The effect of these fillers on cure characteristics and mechanical properties of natural rubber materials at fixed silica content at 35 parts per hundred of rubber (phr) were investigated. The results indicated that ashes showed greater cure time compared to that of the silica. The incorporation of ashes into natural rubber gradually improved compression set but significantly decreased tensile strength, elongation at break, and resilience. Moreover, young's modulus increased, while hardness showed no significant change with the addition of ashes. Overall results indicated that ashes could be used as cheaper fillers for natural rubber materials where improved mechanical properties were not critical.

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.

CHARACTERIZATION AND CORRELATION OF THE NETWORK CHAIN DENSITY TO THE PROPERTIES OF FLUOROELASTOMER RUBBER

2020 ◽  
Vol 93 (2) ◽  
pp. 274-285 ◽  
Author(s):  
M. Boyd ◽  
I. Therrien ◽  
Richard. J. Pazur
Keyword(s):  
Crosslink Density ◽  
Double Quantum ◽  
Steady Increase ◽  
Intensity Data ◽  
Network Chain ◽  
Elongation At Break ◽  
Compression Set ◽  
Low Field ◽  
Subsequent Application ◽  
Corrected Intensity

ABSTRACT The concentrations of triallyl isocyanurate (TAIC) in a peroxide-curable fluoroelastomer terpolymer containing 67 wt% of fluorine were varied to generate compounds of differing crosslink densities. Experimental analysis was undertaken using rheometry, hardness, stress–strain (Mooney–Rivlin), equilibrium solvent swell, and low-field nuclear magnetic resonance (NMR) using the double quantum (DQ) technique. Increasing the TAIC concentration caused a systematic rise in rheometry elastic torque, hardness, and tensile strength, whereas both elongation at break and swelling levels decreased. These results are concurrent with an enhanced overall level of crosslinking, which was confirmed by the steady increase of the Mooney–Rivlin C1 values. DQ NMR analysis using hydrogen and fluorine probes and subsequent application of fast Tikhonov regularization to the corrected intensity data were particularly useful in discerning the inhomogeneous nature of the compound morphology. The spatial distribution of the crosslink density suggests that the compound consists of small, highly crosslinked/entangled polymerized TAIC domains embedded within the elastic crosslinked matrix. A concentration of 3 phr of TAIC is optimal according to compression set testing.

Mechanisms Involved in the Recycling of NR and EPDM

1999 ◽  
Vol 72 (4) ◽  
pp. 731-740 ◽  
Author(s):  
M. A. L. Verbruggen ◽  
L. van der Does ◽  
J. W. M. Noordermeer ◽  
M. van Duin ◽  
H. J. Manuel
Keyword(s):  
Natural Rubber ◽  
Crosslink Density ◽  
Main Chain ◽  
Chain Scission ◽  
Ethylene Propylene ◽  
Temperature Range ◽  
Lower Reactivity ◽  
Ethylene Propylene Diene Rubber ◽  
Diene Rubber ◽  
Crosslink Densities

Abstract The thermochemical recycling of natural rubber (NR) and ethylene-propylene-diene rubber (EPDM) vulcanizates with disulfides was studied. NR sulfur vulcanizates were completely plasticized when heated with diphenyldisulfide at 200 °C. It could be concluded that both main chain scission and crosslink scission caused the network breakdown. NR peroxide vulcanizates were less reactive towards disulfide at 200 °C, and only reacted through main chain scission. For EPDM a temperature range of 200–275 °C was studied. In the presence of diphenyldisulfide at 200 °C there was almost no devulcanization of EPDM sulfur vulcanizates, and at 225 and 250 °C there was only slightly more devulcanization. A decrease in crosslink density of 90% was found when 2×10−4 mol diphenyldisulfide/cm3 vulcanizate was added and the EPDM sulfur vulcanizates were heated to 275 °C. EPDM peroxide vulcanizates showed a decrease in crosslink density of ca. 40% under the same conditions. The lower reactivity of EPDM towards disulfide compared with NR is the result of higher crosslink densities, the presence of a higher percentage of more stable monosulfidic crosslinks and the fact that EPDM is less apt to main chain scission relative to NR.

Application of NR-Based Latex Reclaim: The Link Between Structure and Properties

2007 ◽  
Vol 80 (1) ◽  
pp. 40-60 ◽  
Author(s):  
W. K. Dierkes ◽  
V. V. Rajan ◽  
J. W. M. Noordermeer ◽  
R. Joseph
Keyword(s):  
Viscoelastic Properties ◽  
Crosslink Density ◽  
Virgin Material ◽  
Structure And Properties ◽  
Elongation At Break ◽  
Rubber Blends ◽  
Compression Set ◽  
Vulcanized Rubber ◽  
The Matrix ◽  
Property Profile

Abstract Natural rubber based waste latex rubber (WLR) that is reclaimed with diphenyldisulphide by a thermo-mechanical process is blended with virgin rubber in different proportion to study the change in mechanical and viscoelastic properties. Two types of WLR differing mainly in the amount of polysulfidic linkages are reclaimed and blended with a virgin rubber compound with and without adjustment of the curing system, the former in order to compensate for the extra input of sulfur and accelerators due to the addition of reclaim. The cure behavior, final crosslink density and distribution, mechanical properties and dynamic viscoelastic properties of the blends with reclaimed WLR are compared to the property profile of the virgin material. The morphology of the blends as well as sulfur distribution between the matrix and the reclaim particle is analyzed. With increasing concentrations of WLR reclaim, tensile strength, tear strength and elongation at break decrease, whereas modulus at 100% elongation, compression set and hardness show an increase. The storage modulus of the vulcanized rubber blends decreases with increasing WLR reclaim content in the blend. Swelling measurements show that the crosslink density is reduced for the adjusted cure system but increased for a fixed cure system. These influences of reclaimed WLR on the property profile of a virgin compound will be discussed fundamentally in terms of morphology and crosslink distribution.

scholarly journals Effect of micro sized marble sludge on physical properties of natural rubber composites

2013 ◽  
Vol 19 (2) ◽  
pp. 281-293 ◽  
Author(s):  
Khalil Ahmed ◽  
Shaikh Nizami ◽  
Nudrat Raza ◽  
Khalid Mahmood
Keyword(s):  
Average Molecular Weight ◽  
Cure Rate ◽  
Maximum Torque ◽  
Swelling Properties ◽  
Elongation At Break ◽  
Compression Set ◽  
Natural Rubber Composites ◽  
Cure Time ◽  
Swelling Coefficient ◽  
Marble Waste

Marble waste as sludge is collected from Marble industry, as a way of solving the environmental problem of industrial waste. The sludge was dried, ground and passed through desire sieves (10, 15, 20, 37 and 75 ?m), This powder was characterized by the X-ray fluorescence technique and then incorporated in the formulation of NR composites with different loading of micro sized MS particles (20, 40, 60, 80 and 100 parts per hundred of rubber, phr). The cure characteristics, mechanical properties and swelling properties of MS/NR composites were evaluated. Results indicate that minimum torque, maximum torque, tensile strength, modulus, tear strength, hardness, crosslink density were increased while the scorch time, cure time, cure rate, cure rate index (CRI), elongation at break, compression set, rebound resilience, abrasion loss, swelling coefficient, average molecular weight and filler-rubber interaction decrease with increasing MS loading.

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