ANALYSIS OF CARBON BLACK–REINFORCED CARDANOL-MODIFIED NATURAL RUBBER COMPOUNDS

2015 ◽  
Vol 88 (2) ◽  
pp. 289-309 ◽  
Author(s):  
Sunita Mohapatra ◽  
Golok Bihari Nando
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Multifunctional Additive ◽  
Rubber Compounds ◽  
Bound Rubber ◽  
Link Density ◽  
Polycyclic Aromatic ◽  
Cross Link Density ◽  
Filler Dispersion ◽  
Better Than

ABSTRACT Carbon black is advantageous for rubber as a reinforcing filler. Carbon blacks at higher loadings require process aids for easier processing and improved filler dispersion. Aromatic oils have been used so far in the rubber industry as plasticizer and process aids. The presence of polycyclic aromatic hydrocarbons in these oils has raised concerns, and they have been banned. Rubber industries are looking for alternate sources of process aids from renewable resources. Cardanol (m-pentadecenyl phenol), an agricultural by-product of the cashew industry, is cheap and abundantly available. It was proved recently to be a plasticizer and a multifunctional additive. The dispersion of carbon black in natural rubber (NR) grafted chemically with cardanol (CGNR) is investigated and compared with that of oil plasticized natural rubber. The physico-mechanical properties of the carbon black–filled CGNR vulcanizates are better than that of the aromatic oil plasticized NR vulcanizates. The cross-link density and bound rubber content are higher and the Payne effect is lower for the carbon black–filled CGNR vulcanizates as compared with oil plasticized NR vulcanizates. Dispersion of carbon black in the CGNR matrix is uniform and better than the aromatic oil plasticized NR.

PERFORMANCE COMPARISON OF VARIOUS SURFACE MODIFYING AGENTS ON PROPERTIES OF SILICA-FILLED CHLOROPRENE RUBBER

2017 ◽  
Vol 90 (1) ◽  
pp. 146-158 ◽  
Author(s):  
Chomsri Siriwong ◽  
Pongdhorn Sae-Oui ◽  
Chakrit Sirisinha
Keyword(s):  
Dynamic Properties ◽  
Coupling Efficiency ◽  
Performance Comparison ◽  
Cross Link ◽  
Bound Rubber ◽  
Link Density ◽  
Cross Link Density ◽  
Chloroprene Rubber ◽  
Filler Dispersion ◽  
Rubber Filler

ABSTRACT Influence of the surface modifying agents (SMAs) polyethylene glycol (PEG), 3-aminopropyl triethoxysilane (APTES), and bis-(3-triethoxysilylpropyl)tetrasulfide (TESPT) on properties of silica-filled chloroprene rubber (CR) was investigated. Results reveal that the presence of SMAs greatly improves mechanical and dynamic properties of the silica-filled CR because of the reduced filler–filler interaction and improved rubber–filler interaction as evidenced by the Payne effect and bound rubber content results, respectively. When compared at the same SMA dosage, TESPT gives the best overall vulcanizate properties. This effect is attributed to high coupling efficiency of TESPT and its ability to donate sulfur atoms during vulcanization, leading to the improved filler dispersion, rubber–filler interaction, and cross-link density. APTES gives high coupling efficiency, but because of the lack of sulfur atoms, its performance is slightly inferior to that of TESPT. In contrast, PEG can only reduce filler–filler interaction, with no significant impact on rubber–filler interaction and cross-link density; therefore, PEG provides lower property improvement.

scholarly journals Impact of a nanomixture of carbon black and clay on the mechanical properties of a series of irradiated natural rubber/butyl rubber blend

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 662-670
Author(s):  
Dalal M. Alshangiti
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Theoretical Models ◽  
Butyl Rubber ◽  
Clay Nanoparticles ◽  
Vinyl Silane ◽  
Link Density ◽  
Cross Link Density

Abstract A series of natural rubber/butyl rubber NR/IIR blend loaded with N660 carbon black (CB) and triethoxy vinyl silane treated clay nanoparticles (TCNPs) were prepared using gamma irradiation in the presence of a polyfunctional monomer, trimethylolpropane triacrylate (TMPTA). The effect of incorporating different contents of N660 CB and five parts per hundred of rubber (phr) of treated clay on the mechanical properties of the prepared nanocomposites has been investigated. The addition of TCNP to CB/rubber composites markedly increase their tensile strength due to the increase of the cross-link density. These results indicated that the TCNP may be enclosed or trapped in the occluded structure of CB. The effect of CB and the TCNP content on the tensile strength (σ), elongation at break (ε b, %), and modulus of elasticity (E, MPa) of natural rubber/butyl rubber NR/IIR blend have been investigated. The incorporation of 5 phr of TCNP into 30 phr CB-loaded NR/IIR composites results in the increased tensile strength value by about 60%. Finally, theoretical models were used to interpret the experimental results.

Effect of the cure system on aging resistance of natural rubber compounds

2019 ◽  
Vol 52 (5) ◽  
pp. 397-409 ◽  
Author(s):  
Luciana Ribeiro Honorato ◽  
Regina Celia Reis Nunes ◽  
Jaqueline Guimarães Lima Cosme ◽  
Leila Lea Yuan Visconte ◽  
Augusto Cesar de Carvalho Peres ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Mechanical Performance ◽  
Dynamic Properties ◽  
Lower Number ◽  
Cross Link ◽  
Rubber Compounds ◽  
Before And After ◽  
Link Density ◽  
Cross Links ◽  
Cross Link Density

This work investigates natural rubber (NR) composites vulcanized with different combinations of accelerators in efficient cure systems. The NR compounds were characterized for cross-link density, hardness, tensile strength, and dynamical–mechanical properties, before and after aging. Among the cure systems used, that containing the highest amount of free sulfur presented the best mechanical performance, before and after aging; concerning dynamic properties after the aging, the composition with a lower number of cross-links was the best.

Peroxide vulcanization of natural rubber. Part I: effect of temperature and peroxide concentration

2014 ◽  
Vol 34 (7) ◽  
pp. 617-624 ◽  
Author(s):  
Ján Kruželák ◽  
Richard Sýkora ◽  
Ivan Hudec
Keyword(s):  
Natural Rubber ◽  
Effect Of Temperature ◽  
Side Reactions ◽  
Decomposition Products ◽  
Rubber Compounds ◽  
Peroxide Decomposition ◽  
Link Density ◽  
Rubber Part ◽  
Cross Link Density ◽  
Proper Balance

Abstract Four different peroxides as curing agents were used to prepare vulcanizates based on natural rubber (NR). The effects of temperature and peroxide concentration on the vulcanization characteristics of rubber compounds, cross-link density (ν) and physical-mechanical properties of equivalent vulcanizates were investigated. The results revealed that the vulcanization temperature and also the relative amount of peroxide decomposition products are of significant importance in the properties of vulcanizates. Lower vulcanization temperature and lower concentration of peroxides were found to be better factors, showing a proper balance between the degree of cross-linking of the rubber and degradation of the macromolecular chains by side reactions in relation to the crystallization of NR, which imparts vulcanizates based on NR outstanding properties.

scholarly journals New Vegetable Oils with Different Fatty Acids on Natural Rubber Composite Properties

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1108
Author(s):  
Siwarote Boonrasri ◽  
Pongdhorn Sae-Oui ◽  
Alissara Reungsang ◽  
Pornchai Rachtanapun
Keyword(s):  
Natural Rubber ◽  
Vegetable Oils ◽  
Dynamic Properties ◽  
Rubber Compounds ◽  
Rubber Composite ◽  
Polycyclic Aromatic ◽  
Filler Dispersion ◽  
Moringa Oil ◽  
Composite Properties ◽  
Oil Type

Owing to the toxicity of polycyclic aromatic (PCA) oils, much attention has been paid to the replacement of PCA oils by other nontoxic oils. This paper reports comparative study of the effects of new vegetable oils, i.e., Moringa oil (MO) and Niger oil (NO), on rheological, physical and dynamic properties of silica–filled natural rubber composite (NRC), in comparison with petroleum–based naphthenic oil (NTO). The results reveal that MO and NO exhibit higher thermal stability and better processability than NTO. Cure characteristics of the rubber compounds are not significantly affected by the oil type. It is also found that the NRCs containing MO or NO have better tensile strength and lower dynamic energy loss than the NRCs containing NTO. This may be because both MO and NO improve filler dispersion to a greater extent than NTO as supported by storage modulus and scanning electron microscopy results. Consequently, the present study suggests that MO and NO could be used as the alternative non–toxic oils for NRC without any loss of the properties evaluated.

Simple Method for Determining the Dynamic Coefficient of Friction of Vulcanized Rubber

1951 ◽  
Vol 24 (2) ◽  
pp. 374-380
Author(s):  
B. B. S. T. Boonstra
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Coefficient Of Friction ◽  
Simple Method ◽  
Rubber Powder ◽  
Vulcanized Rubber ◽  
Rubber Compounds ◽  
The Coefficient Of Friction ◽  
Rubber Concrete ◽  
Better Than

Abstract A method for measuring the coefficient of friction at low speeds by means of a normal dynamometer for rubber testing is described. To this end a couple of molded rubber wheels are pulled over a piece of roadlike surface. At the same time the wheels are forced to rotate with a speed nonconcordant with the linear speed on the surface, so that a certain amount of friction occurs. The force necessary to turn the wheels over the surface is recorded on the dynamometer; the average is proportional to the average coefficient of friction. Preliminary experiments were carried out to prove the usefulness of the apparatus. A number of compounds of natural rubber, GR-S, and “cold” rubber were tested on four surfaces: asphalt, asphalt with rubber, concrete, and ground glass. Although the apparatus allows variation of load and of speed, the experiments were carried out at a speed of 100 cm. per minute and only with a load of 4 kilograms. On dry surfaces, the highest coefficient of friction was found with a natural-rubber compound on an asphalt material in which rubber powder had been dispersed. With most rubbers this surface showed a somewhat higher coefficient of friction than did the asphalt without rubber-powder, which in turn was better than the other two surfaces. On the average there was little difference between the various rubber compounds, though natural rubber seemed to yield the highest values. Natural-rubber pure gum compound did not show higher values than the carbon black mixes, but a vulcanizate with cyclorubber instead of carbon black was definitely better.

Influence of Fillers Surface Characteristics on Bound Rubber Properties of Filled Natural Rubber Compounds

2013 ◽  
Vol 845 ◽  
pp. 412-416 ◽  
Author(s):  
Mustafa Kamal Mazlina
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Surface Activity ◽  
Specific Activity ◽  
Filler Particle ◽  
Surface Characteristics ◽  
Rubber Content ◽  
Rubber Compounds ◽  
Bound Rubber ◽  
Service Application

One of the most important phenomena in rubber science is the reinforcement by rigid entities, such as carbon black, clays, silicates and calcium carbonate. Thus, these fillers are added to rubber formulations to optimise properties that meet a given service application or set of performance parameters. Fillers can be divided into three categories reinforcing, semi-reinforcing and non-reinforcing. For a given elastomer and state of mix, bound rubber can be considered as a measurement of a surface activity of a filler and is considered as one of major factors in reinforcement. A strong rubber: filler interaction results in a large bound rubber content. Good dispersions and distribution of filler aggregates is also important for the full reinforcing potential of fillers to be reached. In this study, the influence of fillers on bound rubber content of Natural Rubber compounds were determined and compared. Results showed that the bound rubber content followed the trend of Carbon Black>Silica>Carbon Black>Starch. The two main filler characteristics that affect the bound rubber properties are the filler particle size and surface activity. The specific activity of the filler is determined by the physical and chemical nature of the filler surface in relation to that of elastomer. Keywords: reinforcement, surface energy

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