Experimental and Modeling Study on the Curing Properties of Natural Rubber Composites Filled with Varying Proportions of Carbon Black, Modified Bentonite and Raw Bentonite

2018 ◽  
Vol 934 ◽  
pp. 50-54 ◽  
Author(s):  
Clare L. Garing ◽  
Bryan B. Pajarito
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Control Sample ◽  
Coefficient Of Determination ◽  
Low Oxygen ◽  
Modified Bentonite ◽  
Simplex Lattice ◽  
Experimental Values ◽  
Simplex Lattice Mixture Design ◽  
Torque Values

The aim of this study was to investigate the effect of replacing carbon black (CB) with inexpensive and environmentally friendly fillers – bentonite (BNT) and modified bentonite (M-BNT), on the curing properties of natural rubber (NR) composites. A control sample (unfilled NR) and thirteen NR composites filled with varied proportions of CB (x1), M-BNT (x2), and BNT (x3) based on a third degree – simplex lattice mixture design of experiment (DOE) were prepared in this study. Rheometric results showed that 33% substitution of CB with M-BNT provides the highest elastic torque values. Mixture of 10phr CB and 5phr M-BNT (CB/M-BNT/BNT 10/5/0) produces synergistic effect on curing. The presence of CB increases vulcanization rate due to its high basicity and low oxygen content while M-BNT serves as vulcanizing accelerator due to the present amine groups. Coefficients of reduced hierarchical models showed that the main factors contributed mainly on the curing parameters: β1for the torque values, β2for the scorch and curing time, and β3for CRI. High values of coefficient of determination (r2) were computed particularly for MH(98.20%), ΔS (99.13%), ts2(95.68%), tc90(95.70%) and CRI (95.97%) establishing best fit between the model and experimental values.

Effect of Replacing Carbon Black with Organo-Modified Bentonite and Acid-Activated Zeolite on Vulcanization Characteristics of Natural Rubber Tire Tread

2017 ◽  
Vol 890 ◽  
pp. 59-63 ◽  
Author(s):  
Bryan B. Pajarito ◽  
Kimberly A. Gines ◽  
Angelica S. Baluyut ◽  
Jennielyn Aina A. de Leon ◽  
Ralph P. Villa
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Design Of Experiment ◽  
Mixture Design ◽  
Modified Bentonite ◽  
Rubber Tire ◽  
Cure Time ◽  
Contour Plots ◽  
Simplex Lattice ◽  
Simplex Lattice Mixture Design

The effect of replacing carbon black with organo-modified bentonite and acid-activated zeolite on vulcanization characteristics of natural rubber tire tread was studied using a simplex-lattice mixture design of experiment. Minimum elastic torque ML, maximum elastic torque MH, scorch time ts1, and cure time tc90 of tire treads were modeled in terms of amount of carbon black, organo-modified bentonite, and acid-activated zeolite in the formulation. Contour plots show reduction in ML when carbon black is replaced with a blend of bentonite and zeolite. However, full replacement with acid-activated zeolite increases ML. MH is lowered when carbon black is replaced with bentonite or zeolite. Results also show scorch and curing times to be accelerated when carbon black is replaced with organo-modified bentonite. Meanwhile, vulcanization is retarded as amount of acid-activated zeolite in the formulation is increased.

Effect of Carbon Black Substitution with Raw and Modified Bentonite on the Thermal Aging Resistance of Natural Rubber Composites

2016 ◽  
Vol 705 ◽  
pp. 8-13 ◽  
Author(s):  
Clare L. Garing ◽  
Bryan B. Pajarito
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Thermal Aging ◽  
Clay Platelet ◽  
Aging Resistance ◽  
Contour Plots ◽  
Activated Bentonite ◽  
Simplex Lattice ◽  
Simplex Lattice Mixture Design

The effect of carbon black (CB) substitution with raw (BNT) and modified (M-BNT) bentonite on the thermal aging resistance of natural rubber (NR) composites was investigated in this study. NR composites were prepared at varied proportions of CB, M-BNT, and BNT using a three-component, third degree simplex lattice mixture design of experiment (DOE). M-BNT was produced by modifying sodium-activated bentonite with tetradecyldimethylamine (TDA) salt and cocamide diethanolamine (CDEA). Thermal aging was performed at 70 and 100°C for 168 and 336 h. Substitution of CB with 5 phr M-BNT gave the highest values of tensile properties (modulus and strength) for both unaged and aged samples. This is attributed to the synergistic effect of CB and M-BNT fillers on the tensile properties of NR composites. In terms of property retention (%), composites filled with M-BNT and BNT clay fillers attained the highest values which signified their excellent thermal aging resistance. This observation proves the barrier effect of clay platelet structure which hinders oxygen diffusion in the rubber. Reduced hierarchical models as function of CB, M-BNT, and BNT proportions were used to generate contour plots for tensile properties of NR composites after 168 h of aging at 70 and 100°C.

Effect of Replacing Carbon Black with Surfactant-Modified Natural Feldspar on Mechanical Properties of Natural Rubber Composites

2017 ◽  
Vol 890 ◽  
pp. 24-27
Author(s):  
Noel Jeffrey P. Pinton ◽  
Bryan B. Pajarito
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
Natural Rubber ◽  
Stress Transfer ◽  
Rubber Composites ◽  
Complete Replacement ◽  
Natural Rubber Composites ◽  
Filler Dispersion ◽  
Simplex Lattice ◽  
Simplex Lattice Mixture Design

The effect of replacing carbon black (CB) with surfactant-modified natural feldspar (SMNF) on hardness and tensile properties of natural rubber (NR) composites was studied using a simplex-lattice mixture design of experiment. SMNF was produced by treating natural feldspar (NF) with coconut diethanolamine (CDEA) and glycerol monostearate (GMS). Complete replacement of CB with SMNF based from CDEA or GMS decreased Shore A hardness and tensile stress at all elongations. NR composites reinforced with SMNF based from GMS exhibited higher mechanical properties than from CDEA which is attributed to the higher hydrophobicity factor of GMS. CDEA may also have aggregated on the surface of NF, resulting to poor filler dispersion and ineffective stress transfer.

Moisture Diffusion in Silica/Clay/Natural Rubber Hybrid Composites

2019 ◽  
Vol 22 ◽  
pp. 9-18
Author(s):  
Bryan B. Pajarito ◽  
Mark Rigel R. Ali
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Water Uptake ◽  
Hybrid Composites ◽  
Bentonite Clay ◽  
Moisture Diffusion ◽  
Type Model ◽  
Diffusion Behavior ◽  
Simplex Lattice ◽  
Simplex Lattice Mixture Design

This study investigated moisture diffusion in natural rubber (NR) hybrid composites filled with silica and bentonite clay. Natural bentonite (BNT) was treated with tetradecyldimethylammonium chloride and coco diethanolamide to produce modified bentonite (M-BNT). Varied proportions of silica, M-BNT, and BNT fillers were added to raw NR according to a third-degree simplex lattice mixture design of experiment. The addition of fillers affects the vulcanization characteristics, mechanical properties, and hardness of NR hybrid composites. Moisture diffusion behavior was studied by monitoring the water uptake of NR composites during immersion in deionized water at 80°C. Data from sorption experiments were fitted on the classical Fickian and Langmuir-type diffusion models. The Fickian model overestimates and underestimates the water uptake of NR composites in the early and later stages of moisture diffusion, respectively. On the other hand, the Langmuir-type model adequately captures the anomalous diffusion behavior of moisture in NR composites. Parameters of the Langmuir model (equilibrium water uptake and diffusion coefficient) vary with the composition of hybrid fillers. Optimum proportions of silica, M-BNT, and BNT in rubber composites were obtained by considering the effect of fillers on mechanical properties and moisture diffusion characteristics of NR.

scholarly journals Properties Characterization of Vulcanized Natural Rubber Filled with Uncarbonized Particulate Cow Bone

2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Akinlabi Oyetunji ◽  
Isiaka O Bakare ◽  
Reginald Umunakwe ◽  
Adetola O Adeyemo
Keyword(s):  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Abrasion Resistance ◽  
Control Sample ◽  
Filler Loading ◽  
Rubber Composites ◽  
Compression Moulding ◽  
Natural Rubber Composites ◽  
Cow Bone

This work investigates the effects of addition of 63 µm uncarbonized particulate cow bone as fillers in vulcanized natural rubber on the tensile properties, hardness and abrasion resistance of the composites. Cow bones were procured from an abattoir, cleaned, crushed, pulverized, ball milled and sieved to obtain the particles that passed through the 63 µm mesh size. Natural rubber composites materials were prepared varying the filler loading as 5, 10, 15 and 20 pphr respectively. The compounded rubber samples were cured in a hot press using compression moulding technique. The control sample was produced using 20 pphr of carbon black. The cured rubber samples were conditioned at room temperature for two weeks before they were characterized. The tensile strength and elastic modulus of the samples filled with cow bone increased with filler loading up to 15 pphr before they started decreasing. Carbon black reinforced sample possessed higher tensile strength, modulus and hardness than the samples filled with uncarbonized particulate cow bone. The hardness for all samples maintained an increasing trend with increase in the filler loadings. Particulate cow bone reinforced natural rubber offered higher elongation than carbon black reinforced samples. At 10, 15 and 20 pphr, cow bone reinforced composites exhibited higher abrasion resistance than carbon black filled sample. The optimal filler loading of uncarbonized particulate cow bone reinforced natural rubber was 15 pphr.  Cow bone reinforced natural rubber can find applications in areas where moderate strength, hardness, elongation and wear resistance are required such as in protective footwear, bouncing balls and cases of children toys.Keywords— carbon black, cow bone, fillers, natural rubber, composites.

Mechanical Properties of Ternary-Filled Natural Rubber Composites

2019 ◽  
Vol 821 ◽  
pp. 111-117 ◽  
Author(s):  
Clare L. Garing ◽  
Bryan B. Pajarito
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Compressive Performance ◽  
Contour Plots ◽  
Simplex Lattice ◽  
Reflectance Ftir ◽  
Atr Spectroscopy ◽  
Simplex Lattice Mixture Design

The aim of this study was to investigate the effect of each ternary filler component: carbon black (CB), modified bentonite (M-BNT), and raw bentonite (BNT), and their interactions, on the mechanical properties of natural rubber (NR) composites, using a third degree-simplex lattice mixture design of experiment. The efficiency of the two-step organic modification to produce M-BNT was confirmed by the results of Fourier transform infrared with attenuated total reflectance (FTIR-ATR) spectroscopy and x-ray diffraction (XRD) analysis. Synergistic effect between CB and M-BNT on the mechanical properties of NR composites with ternary filler composition 10/5/0 was observed. Reinforcement of NR matrix using this ternary filler enhanced its tensile properties: strength (69.43%), modulus (47.01%), stress at 100% strain (34.67%), stress at 200% strain (41.88%), and stress at 300% strain (50.82%), as well as its compressive properties: strength (40.89%), modulus (40.05%), stress at 20% strain (41.10%), stress at 40% strain (37.57%), and stress at 60% strain (40.79%). Significant improvement in the mechanical properties was also attributed to the surface modification of M-BNT resulting to better dispersion to NR matrix. The addition of pure BNT filler resulted to lowest tensile and compressive performance due to high clay loading and incompatibility with NR matrix. Trends of the generated contour plots based on reduced hierarchical models demonstrated synergy between CB and M-BNT as well as deterioration of mechanical properties upon addition of pure BNT filler 0/0/15.

Extraction and identification of fillers and pigments from pyrolyzed rubber and tire samples

1996 ◽  
Vol 54 ◽  
pp. 174-175
Author(s):  
P. Sadhukhan ◽  
J. B. Zimmerman
Keyword(s):  
Zinc Oxide ◽  
Electron Microscope ◽  
Carbon Black ◽  
Natural Rubber ◽  
Transmission Electron Microscope ◽  
Rolling Resistance ◽  
Synthetic Polymers ◽  
Nitrogen Atmosphere ◽  
Transmission Electron ◽  
Curing Agents

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.

Rubber Fracture Characterization Using J-Integral

1988 ◽  
Vol 16 (1) ◽  
pp. 44-60 ◽  
Author(s):  
C. L. Chow ◽  
J. Wang ◽  
P. N. Tse
Keyword(s):  
Crack Initiation ◽  
Carbon Black ◽  
Natural Rubber ◽  
Fracture Parameter ◽  
J Integral ◽  
Specimen Length ◽  
Fracture Characterization ◽  
Premature Failure ◽  
Testing Procedures ◽  
Material Evaluation

Abstract The use of the J-integral to investigate fracture characterization in a carbon black reinforced natural rubber is described. Three applications to crack initiation are included: two based on the use of a hypothetical zero specimen length and one on conventional testing procedures for metals. While the validity of the zero-length methods is questionable, the conventional method yielded a consistent Jc value of 1.01 N/mm for a typical tire compound. This value was obtained from 24 combinations of varying specimen geometries and pre-crack lengths. The J-integral is revealed as a valid fracture parameter that is applicable not only for material evaluation but also for designing tire structures to resist premature failure. These conclusions disagree with those from an earlier investigation, so the causes for the discrepancies are examined and discussed.

Elaboration of novel adsorbent from Moroccan oil shale using Plackett–Burman design

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Methylene Blue ◽  
Oil Shale ◽  
Screening Method ◽  
Raw Material ◽  
Coefficient Of Determination ◽  
Processing Temperature ◽  
Acid Pretreatment ◽  
Experimental Data Processing ◽  
Experimental Values ◽  
Maximal Capacity

The new adsorbents were prepared from Moroccan oil shale by chemical and physical process .In this study, experimental Plackett-Burman has been used as a screening method to study six factors for the development of materials to adsorbent basis of oil shale Moroccan. The factors have been identified by two levels, To Know temperature (°C), Processing time (min), mass ratio (m precursor/m acid), Pretreatment mixture the precursor with acid, origin of the raw material and type of the activating agent (H2SO4, H3PO4).And it was chosen as a response The maximum quantity of adsorption of the molecule of Methylene blue (Qads in mg/g) and the specific surface measure by the method bet (Sbet in m2/g), The predicted values were in agreement with the experimental values with a coefficient of determination (R2) of 0.98. The model has been validated by experiments subsequent to optimized conditions. The experimental data processing by software JMP 7 showed that the processing temperature The report of oil shale on the acid and activation time were the important effect on the maximal capacity of adsorption of methylene blue. The sample prepared at 237 °C during 215 min with pre-processing has a maximal capacity of adsorption equal to 54mg/g according to model of adsorption of Langmuir and SBET equal to 143 m2/g.

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