Effect of Vulcanization Temperature and Different Fillers on the Properties of Efficiently Vulcanized Natural Rubber

1979 ◽  
Vol 52 (2) ◽  
pp. 263-277 ◽  
Author(s):  
R. Mukhopadyay ◽  
S. K. De
Keyword(s):  
Particle Size ◽  
Natural Rubber ◽  
Crosslinking Density ◽  
Filler Loading ◽  
Zinc Stearate ◽  
Curing Temperature ◽  
Abnormal Behavior ◽  
Elongation At Break ◽  
Polymer Filler ◽  
Reinforcing Fillers

Abstract The present work deals with effect of vulcanization temperature on the polymer-filler interaction parameter, vulcanizate structure, and the technical properties of efficiently vulcanized natural rubber stocks in the presence of different fillers. We have used carbon blacks of four different particle sizes (ISAF, HAF, SRF, FT), reinforcing silica, and whiting. In the case of black fillers, as the particle size increases, reversion resistance increases. For all fillers, an increase of curing temperature from 150 to 180°C caused a reduction in strength, modulus, hardness, resilience; and an increase in elongation at break, compression set, and heat build-up. However, the flexing properties and abrasion loss showed improvement at higher curing temperature. Kraus' plots indicate that increase of curing temperature caused reduction in polymer-filler attachment. At both curing temperatures, the activity of fillers follow the order, ISAF > HAF > SRF > FT. Silica showed erratic behavior in that Kraus plots indicate nonreinforcement by the filler. Whiting also behaved abnormally with respect to Kraus plots; at lower filler loading, the system is nonadherent, becoming weakly adherent at higher concentrations. The abnormal behavior of silica-filled compounds has been explained on the basis of a reaction on the silica surface between silanol groups and zinc stearate. Westlinning and Wolff's αF values were found to be independent of curing temperature and characteristic of fillers only (the larger the particle size, the lower is the αF value). The increase in apparent crosslinking density in the case of reinforcing fillers is due to increased υr arising out of increased polymer-filler interaction. Therefore, the sulfur inefficiency parameters (E values) and zinc sulfide efficiency parameters (F values) become less significant in filled vulcanizates.

Natural Rubber-Whisker Alumina Fiber Composite Materials for Mechanical and Thermal Insulation Applications

2018 ◽  
Vol 789 ◽  
pp. 221-225
Author(s):  
Nattapol Dedruktip ◽  
Wasan Leelawanachai ◽  
Nuchnapa Tangboriboon
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Natural Rubber ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Curing Temperature ◽  
Mechanical And Thermal Properties ◽  
Alumina Fiber ◽  
Elongation At Break

Alumina fiber is a ceramic material used as a dispersed phase or filler to reinforce the mechanical and improve thermal properties of natural rubber via vulcanization process at curing temperature 150°C. The amount of alumina fiber added in natural rubber was varied from 0 to 50 phr on 100 phr of natural rubber in a sulfur curing system. Adding 10 phr alumina fiber affects to obtain the best natural rubber composite samples having good mechanical and thermal properties. Tensile strength, elongation at break, Young’s modulus and thermal conductivity of adding 10 phr whisker alumina fiber encoded NR-Al-10 are equal to 14.38±1.95 MPa, 1038.4±41.45%, 545.63±25.67 MPa and 0.2376±0.0003 W/m.K, respectively, better than those of pure natural rubber compounds without adding alumina fiber. Tensile strength, elongation at break, Young’s modulus and thermal conductivity of natural rubber without adding alumina fiber are equal to 14.06±6.03 MPa, 949.41±52.15%, 496.32±8.54 MPa and 0.2500±0.0003 W/m.K, respectively.

Waste Silicon Carbide as Filler for Natural Rubber Compounds

2014 ◽  
Vol 979 ◽  
pp. 155-158 ◽  
Author(s):  
Apaipan Rattanapan ◽  
Jitrakha Paksamut ◽  
Pornsri Pakeyangkoon ◽  
Surakit Tuampoemsab
Keyword(s):  
Silicon Carbide ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Shear Viscosity ◽  
Tensile Modulus ◽  
Filler Loading ◽  
Extrudate Swell ◽  
Elongation At Break ◽  
Roll Mill ◽  
Cure Time

This work studied possibilities of using waste silicon carbide (SiC) particles from abrasive industry as alternative filler in natural rubber (NR) compounds. The rubber was prepared by using natural rubber grade STR 5L and waste silicon carbide loading of 0, 10, 20, 30 and 40 phr. Firstly, the rubber were compounded by using two roll mill and then using Oscillating Disc Rheometer for studying cure time at one hundred and fifty degree Celsius. Then, shear viscosity and extrudate swell of the compounded natural rubber were characterized by using capillary rheometer at 100°C. The result showed that the apparent shear viscosity increased slightly with increasing waste silicon carbide loading and the percentage of extrudate swell was found to be a decreasing function of the filler loading. Then, test tensile by using the prepared samples for studying tensile modulus, tensile strength and elongation at break. The result showed that tensile modulus and tensile strength increased with increasing waste silicon carbide. On the other hand, the elongation at break of the filled natural rubber decreased with increasing waste silicon carbide. Finally, bring the sample to test hardness by using shore A. Results indicated that waste silicon carbide direct variation with the indicator of hardness.

Effect of Peroxide Content on Morphology and Properties of Thermoplastic Vulcanizates Based on PP and NR

2011 ◽  
Vol 284-286 ◽  
pp. 1854-1860 ◽  
Author(s):  
Rui Wang ◽  
Zheng Peng ◽  
Peng Peng Fan
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Shear Stress ◽  
Elastic Modulus ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Elongation At Break ◽  
Peroxide Content ◽  
Thermoplastic Vulcanizates ◽  
Rubber Phase

Thermoplastic vulcanizates (TPVs) of natural rubber (NR) and polypropylene (PP) (60:40) containing various dosages (0.5-5.5phr) of peroxide were prepared using a Haake Rheocord. The effects of peroxide content on the crosslink density, thermal behaviors, morphology, mechanical and rheological properties of NR/PP TPVs were studied. The crosslink density of TPVs increased with increasing of peroxide content. However, the tensile strength, tear strength and elongation at break obtained the maximum values when 2.5phr peroxide was added, which was ascribed to the presence of smallest particle size of crosslinked rubber phase at this peroxide content. It was proposed that the effect of DCP, which not only initiated crosslink reaction in NR phase, but also degraded the polypropylene molecules, played an important role in determined the morphology and properties of TPVs. The viscosity of TPVs decreased with shear stress, indicating pseudoplastic nature of the TPV samples. The elastic modulus of the samples gradually increases with the increase in DCP content.

Composites of Cysteamine Functionalised Graphene Oxide and Polypropylene

2021 ◽  
Vol 36 (3) ◽  
pp. 297-313
Author(s):  
S. S. Abbas ◽  
T. McNally
Keyword(s):  
Graphene Oxide ◽  
Crystallization Behavior ◽  
Polymer Network ◽  
Filler Loading ◽  
Elongation At Break ◽  
Polymer Filler ◽  
Reduced Graphene ◽  
Crystallisation Temperature ◽  
Covalent Bridging ◽  
Rheological Percolation

Abstract Cysteamine functionalised reduced graphene oxide (rGO) was grafted to polypropylene-graft-maleic anhydride (PP-g-MA) and subsequently melt blended with PP. The covalent bridging of rGO to PP-g-MA via the cysteamine molecule and co-crystallization are routes to promoting interfacial interactions between rGO and the PP matrix. A rheological percolation threshold was achieved for a nanofiller loading between 3 wt% and 5 wt%, but none detected for the composites prepared with un-functionalized rGO. At low loadings (0.1 wt%), functionalized rGO is well dispersed in the PP matrix, an interconnecting filler-filler, polymer-filler and polymer-polymer network is formed, resulting in increased tensile toughness (1 500%) and elongation at break (40%) relative to neat PP. Irrespective of whether the rGO was functionalised or not, it had a significant effect on the crystallization behavior of PP, inducing heterogeneous nucleation, increasing the crystallisation temperature (Tm) of PP by up to 10°C and decreasing the crystalline content (Xc) by ∼30% for the highest (5 wt%) filler loading. The growth of the monoclinic a-phase of PP is preferred on addition of functionalised rGO and b crystal growth suppressed.

INVESTIGATION OF HEMPSEED PROCESS OIL AS THE ALTERNATIVE IN NATURAL RUBBER COMPOUNDING PROCESS

2021 ◽  
Author(s):  
Julijana Blagojević ◽  
◽  
Olga Govedarica ◽  
Kojić Predrag ◽  
Oskar Bera ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Rotor Speed ◽  
Elongation At Break ◽  
Rubber Industry ◽  
Mineral Oils ◽  
Rubber Compounds ◽  
Reinforcing Fillers ◽  
Environmentally Friendly Process ◽  
Batch Mixer ◽  
Selection Of

Good selection of natural rubber compounds is substantial in rubber industry. Behavior of products based on natural rubber is determined by rubber blending components, especially nature of process oil and concentration of reinforcing fillers. Rubber process oil main purpose is to improve dispersibility of fillers and reduce the viscosity of the rubber compound, therefore enable better processing. Mineral oils are mostly used process oils in natural rubber compounding, but, due to their toxicity and new requirements for preservation of the environment, more and more well-known manufacturers have turned to the use of environmentally friendly process oils. In this study, influence of the hempseed oil as process oil on the products properties in natural rubber compounding was investigated. Properties of hempseed oil as process oil were experimentally determined or calculated. Blending of natural rubber was performed in a laboratory by internal batch mixer, at the constant temperature of 90°C and a rotor speed of 60 rpm. Main rubber properties such as hardness, tensile strength, elongation at break, modulus at 100 and 300% elongation, and rheological properties were determined. Also, voltage and amperage were experimentally measured for calculating power consumption during effective mixing phase in rubber blending.

Effect of palmyra palm fiber filler on properties of natural rubber vulcanizate

2014 ◽  
Vol 11 (6) ◽  
pp. 565-574
Author(s):  
J. Nwabanne ◽  
P. Igbokwe ◽  
E. Ezeonyebuchi
Keyword(s):  
Particle Size ◽  
Carbon Black ◽  
Natural Rubber ◽  
Surface Area ◽  
Filler Loading ◽  
Partial Replacement ◽  
Average Particle ◽  
Swelling Properties ◽  
Palm Fiber ◽  
Loading Ratio

The effect of partial replacement of carbon black by Palmyra palm fiber on the cure characteristics, physico-mechanical and swelling properties of natural rubber vulcanizates was studied. The Palmyra palm fibers were extracted, treated and characterized so as to determine pH, moisture content, and ash content, loss on ignition, conductivity, cellulose, lignin, Hemicellulose, cellulose/lignin ratio and Acid soluble lignin. The functional groups in the Palmyra palm fiber was also determined using FTIR. The Palmyra palm powder with an average particle size of 75 μm was used in this study. The natural rubber/carbon black/Palmyra palm fiber (NR/CB/PPF) composites having eight different loadings, 0/70, 10/60, 20/50, 30/40, 40/30, 50/20, 60/10, 70/0, were prepared using a laboratory size two roll mill. The maximum Torque of NR/CB/PPF composites increased with increasing commercial filler loading ratio. The scorch time and cure time of NR/CB/PPF composites decreased as the ratio of CB loading increased. The tensile strength, modulus of elongation, tear strength and abrasion resistance of all the composites increased as the commercial filler loading ratio increased. This is due to the presence of the commercial filler which gave a better filler interaction. Also this behavior can be attributed to the particle size and surface area of the fillers used as the fillers with small particle size usually have a larger surface area which supports better filler-rubber interaction. The hardness increased as the palmyra palm fiber loading increased. The elongation at break decreases as carbon black filler loading increases except for the composite with CB/PPF ratio of 10/60. The effect of filler loading on the swelling behavior of NR/CB/PPF composites was also investigated in aromatic and aliphatic compounds. Result showed that the composites with more carbon black has less absorption than those with more palmyra palm fiber showing that the compounds with more carbon black has better interaction than those with palmyra palm fiber.

Preparation and Characterization of Rice Husk Powder Incorporated Natural Rubber Latex Foam

2012 ◽  
Vol 626 ◽  
pp. 523-529 ◽  
Author(s):  
Shamala Ramasamy ◽  
Hanafi Ismail ◽  
Yamuna Munusamy
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Rice Husk ◽  
Structural Characterization ◽  
Natural Rubber Latex ◽  
Filler Loading ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Rice Milling

Rice husk powder (RHP) is an abundant agricultural by product that is produced in bulk quantity as part of rice milling. This research is carried out to incorporate RHP with natural rubber latex (NRL) compound. Different loading of RHP is added to NRL compound and is foamed to make natural rubber latex foam (NRLF) using a well known technique called the Dunlop method. The tensile properties of modified NRLF is studied and compared with the controlled NRLF which has zero RHP loading. The morphology and micro structural characterization has been performed by Tabletop microscopy (TM1000). The tensile strength decreases at 2.5 pphr but increases again as the filler loading increases. Elongation at break decreases whereas modulus at 100% elongation (M 100) and hardness increases as the filler loading increases.

Influence of Pyrolytic Carbon Black Prepared from Waste Tires on Mechanical Properties of Natural Rubber Vulcanizates

2017 ◽  
Vol 751 ◽  
pp. 332-336 ◽  
Author(s):  
Sarawut Prasertsri ◽  
Sansanee Srichan
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
Natural Rubber ◽  
Pyrolytic Carbon ◽  
Filler Loading ◽  
Elongation At Break ◽  
Cure Time ◽  
Mooney Viscosity ◽  
Heat Build Up ◽  
Natural Rubber Vulcanizates

This research aimed to investigate the possibility of pyrolytic carbon black (PCB) used as filler in natural rubber (NR) and its effect on Mooney viscosity, cure characteristics and mechanical properties compared with commercial carbon black (N774). The results revealed that Mooney viscosity, stiffness and heat build-up tended to increase with increasing both PCB and N774 loading, whereas elongation at break decreased. However, the maximum tensile and tear strengths appeared at the optimum filler loading for both PCB and N774. At similar filler content, PCB-filled NR compounds have higher cure time, heat build-up and thermal resistance. Nevertheless, they exhibited lower Mooney viscosity and mechanical properties compared to N774-filled NR. Finally, it can be concluded that PCB could be utilized as filler in NR compound to act as semi-reinforcing filler and was classified as a filler to reduce costs.

scholarly journals Treatment’s effect on mechanical properties of kenaf bast/natural rubber latex foam

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9507-9522
Author(s):  
Nurul Jannah Sallehuddin ◽  
Hanafi Ismail
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Filler Loading ◽  
Rubber Matrix ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Morphological Studies ◽  
Recovery Percentage ◽  
Kenaf Bast

Non-treated and silane-treated kenaf bast/natural rubber latex foam (NRLF) were prepared using the Dunlop method at different filler loading (0, 3, 5, and 7 pphr). The properties were investigated in terms of mechanical properties, tensile, compression, hardness, and swelling behavior. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize kenaf bast/NRLF. With the modulus at 100% elongation (M100), the compression strength and hardness showed increments in value with increments of kenaf loading. However, different results showed in tensile strength, elongation at break, swelling percentage, and recovery percentage, which decreased at higher filler loading. Silane-treated kenaf bast/NRLF showed higher value in all properties except for elongation at break, swelling, and recovery percentage. The improvement of properties was supported by SEM surface morphological studies that showed better adhesion between the rubber matrix and kenaf filler.

Effect of Rice Husk Particle Size on Tensile and Density of Recycled PPVC Composite

2013 ◽  
Vol 812 ◽  
pp. 145-150 ◽  
Author(s):  
Azizul Rahman Farah Nordyana ◽  
Ahmad Zafir Romli ◽  
Mohd Hanafiah Abidin
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Tensile Properties ◽  
Rice Husk ◽  
Filler Loading ◽  
Particle Sizes ◽  
Hot Press ◽  
Rice Husks ◽  
Elongation At Break ◽  
Density Result

This study is to measure the effect of various rice husks particle size on density, tensile strength, Youngs modulus and elongation at break of PPVC composite. Rice husk was grind before being sieved to particle sizes of 60 μm, 60 μm < particle size 80 μm, and 80 μm < particle size 100μm. Each size was compounded with PPVC at same filler loading which is 20 % rice husk and being pressed using hot press machine. Tensile strength, Youngs modulus and elongation at break increased as particle size increases. The highest value for tensile strength, Youngs modulus and elongation at break are 21.48 MPa, 1344.88 MPa and 2.29 % respectively. However, it is different for density result which decreased as particle size increases. The results obtained from the study shows that the bigger the size of the rice husks, the better the composite tensile properties.

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