Mechanism of Improved Aged Rubber-to-Brass Adhesion Using One-Component Resins

2005 ◽  
Vol 78 (1) ◽  
pp. 155-173 ◽  
Author(s):  
Pankaj Y. Patil ◽  
William J. van Ooij
Keyword(s):  
Natural Rubber ◽  
Rubber Matrix ◽  
Corrosion Performance ◽  
Iron Dissolution ◽  
Pull Out ◽  
Rubber Compounds ◽  
New Findings ◽  
Steel Cord ◽  
Initial Heat

Abstract Using a squalene liquid rubber modeling approach, we have shown recently that the role of an adhesion promoting one-component resin system is similar to the conventional resorcinol based two-component resin system1. However, to further study the effect of resins in real natural rubber based formulations, eight similar formulations were mixed to make compounds in natural rubber. These rubber compounds were characterized and tested for their mechanical properties viz. stress at break, stress at 300% strain, elongation %, initial, heat and humidity aged wire adhesion pull-out test, tensile tear strength test. Furthermore, to confirm our proposed theory of the migration of resins from the rubber matrix towards the surface, the surfaces of the rubber compounds were studied using ATR-FTIR spectroscopy. NMR spectroscopy was performed on the rubber compounds to study the sulfur crosslink density distribution. Based on our new findings relating to improved corrosion performance of sulfidized brass cords a theory has been put forward that loss of rubber-to-brass adhesion is in fact due to the aging of the brass cord. This aging of brass cord is found to be due to the dissolution of iron from the steel cord. It was observed that the use of different formulations affected the corrosion performance of the sulfidized brass cords in a different manner. The use of resins, particularly one-component resins, seemed to inhibit this iron dissolution thus resulting in durable rubber-to-brass adhesion even in the humidity aged adhesion blocks.

scholarly journals Microalgal biomass as renewable biofiller in natural rubber compounds

2021 ◽  
Author(s):  
Emanuela Bellinetto ◽  
Riccardo Ciapponi ◽  
Marco Contino ◽  
Claudia Marano ◽  
Stefano Turri
Keyword(s):  
Thermal Analysis ◽  
Carbon Black ◽  
Natural Rubber ◽  
Shear Fracture ◽  
Pure Shear ◽  
Rubber Matrix ◽  
Compression Moulding ◽  
Microalgal Biomass ◽  
Dynamic Mechanical ◽  
Rubber Compounds

AbstractMicroalgal biomasses, consisting of micronized Spirulina Platensis and its low protein fraction, were investigated in this work as possible renewable biofillers in natural rubber compounds, with the aim of replacing the commonly used carbon black. Natural rubber, in some cases blended with 10% of epoxidized natural rubber to improve the matrix-filler affinity, was compounded with 25, 35, 50 and 75 phr of each biomass. Compounds with 25, 35 and 50 phr of carbon black N990 were also prepared as benchmarks. After compounding, vulcanization times were determined by dynamic mechanical analysis. Rubbers were vulcanized by compression moulding and characterized by means of morphological analysis (scanning electron microscopy), thermal analysis (thermogravimetric analysis, dynamic mechanical thermal analysis) and mechanical tests (tensile tests, strain induced crystallization detection by X-ray diffraction, pure shear fracture tests). Microalgal biomass turned out to be homogeneously dispersed in natural rubber matrix and the materials obtained required lower curing times compared to carbon black compounds. It was found that, up to 50 phr, Spirulina has the ability to increase rubber tensile strength and modulus, acting similarly to N990, while decreasing rubber thermal stability and fracture toughness.

Role of Antiozonants in Modern Tire Compounding

1964 ◽  
Vol 37 (4) ◽  
pp. 973-989 ◽  
Author(s):  
E. R. Thornley
Keyword(s):  
Natural Rubber ◽  
Antioxidant Properties ◽  
Good Deal ◽  
Partial Replacement ◽  
Protective Agents ◽  
Rubber Compounds ◽  
Heat Degradation ◽  
Protective System ◽  
Oxidative Processes

Abstract The need to provide tire compounds with improved resistance to ozone has been very largely met by the use of N,N′ disubstituted-p-phenylenediamines as protective agents. These chemicals are for this reason commonly thought of as antiozonants but they also possess important antioxidant properties and in considering their role in modern compounding, it is necessary to distinguish between their antiozonant and antioxidant functions. The choice of protective system used in any particular tire component depends a good deal on the nature of the polymer. The relative behavior of natural rubber and SBR with respect to ozone cracking and flexcracking is demonstrated by data given in the paper and it is shown how a typical “antiozonant” such as isopropyl phenyl-p-phenylenediamine (IPPD) will protect SBR tread and sidewall compounds principally from static and dynamic ozone cracking and natural rubber compounds not only from ozone attack but also from various oxidative processes such as flexcracking, cut-growth and heat degradation. The effects of the partial replacement of natural rubber and SBR by polybutadiene on the antiozonant and antioxidant requirements of such tire compounds are also briefly considered.

Effect of Compounding Ingredients and Crosslink Concentration on Blooming Rate of Natural Rubber Compounds

2015 ◽  
Vol 1134 ◽  
pp. 50-55 ◽  
Author(s):  
Ummu Qani’ah Yasin ◽  
Dzaraini Kamarun ◽  
Che Mohd Som Said ◽  
Azemi Samsuri
Keyword(s):  
Diffusion Process ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Crystalline Material ◽  
Rubber Matrix ◽  
Opposite Trend ◽  
Rubber Compounds ◽  
Rubber Surface ◽  
Different Types ◽  
High Peroxide

Blooming is a diffusion process whereby compounding ingredients dispersed in rubber matrix migrate to the rubber surface and appears as a layer of white crystalline material. Blooming is a typical phenomenon observed in rubber compounds which could lead to problems such as discoloration and poor appearance of products as well as loss of adhesion. Cause of blooming was still unclear and this research was carried out to identify the effect of compounding ingredients and crosslink concentration on blooming rate in natural rubber compounds. In this project 6 natural rubber formulations based on three different types of compounding ingredients at two different concentrations of crosslinker were compounded and tested for their blooming characteristics. Sulphur, wax and dithiocarbamate as the compounding ingredients were mixed with natural rubber in the presence of 1 and 6 phr of peroxide as the vulcanizing agents. The effect of crosslink concentration on blooming rate of the compounded rubber was then determined. The blooming rate was determined by the weight of the blooming material on the rubber surface as a function of time. The blooming rate was found to be affected by the types of compounding ingredients and crosslink density of rubber. Wax with 6 phr of peroxide showed the highest amount of bloom and the highest blooming rate while the dithiocarbamate accelerator with 1 phr peroxide showed the lowest amount of bloom and the lower blooming rate. As expected, all the compounding ingredients showed an increase of crosslink concentration as the loading of peroxide increases. The blooming rate was also found to be affected by the crosslink concentration of rubber. As the crosslink concentration increases, the rate of blooming increases as were shown by wax and dithiocarbamate accelerator. However, sulphur showed the opposite trend whereby the crosslink concentration increases but the blooming rate decrease. This could be due to the high peroxide level retarding the sulphur blooming process.

EPDM/SBR Blends for Skim Compound of Steel Cord Conveyor Belt: Mechanical Properties, Thermal Stability and Adhesion Level

2021 ◽  
Vol 889 ◽  
pp. 135-143
Author(s):  
Nguyen Thanh Liem ◽  
Nguyen Pham Duy Linh ◽  
Nguyen Huy Tung ◽  
Bach Trong Phuc
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Thermal Aging ◽  
Conveyor Belt ◽  
Elongation At Break ◽  
Pull Out ◽  
Rubber Compounds ◽  
Aging Properties ◽  
Steel Cord ◽  
Adhesion Level

In this paper, the influence of some ingredient concentrations such as SBR ratio, DCP/S, CBS/DPG accelerator, EPDM-g-AM and cord surface on mechanical, thermal aging properties and adhesion between rubber compounds and cord have been investigated. The results showed that with suitable ingredients loading such as EPDM/SBR is 85/15 phr, DCP/S is 2.0/1.5 phr and EPDM-g-AM content is 2.0 phr with respect to rubber, the vulcanizates had good mechanical properties, thermal stability and adhesion level to the zinc/copper galvanized cord. The highest tensile strength, elongation at break and pull out strength reached 18.1 MPa, 432% and 60.3 N/mm respectively, and the highest retention after thermal aging at 150°C for 168 hours was about 0.76.

The Effect of Chitosan Loading on the Properties of Chitosan Filled Epoxidized Natural Rubber Compounds

2011 ◽  
Vol 471-472 ◽  
pp. 851-856 ◽  
Author(s):  
S.M. Shaari ◽  
Hanafi Ismail ◽  
Nadras Othman
Keyword(s):  
Natural Rubber ◽  
Tensile Modulus ◽  
Epoxidized Natural Rubber ◽  
Rubber Matrix ◽  
Curing Time ◽  
Maximum Torque ◽  
Elongation At Break ◽  
Rubber Compounds ◽  
Curing Characteristics ◽  
Roll Mill

The study of chitosan loading onto epoxidized natural rubber compounds were prepared by incorporation of chitosan into epoxidised natural rubber matrix using a two-roll mill. The effects of chitosan loading on the curing characteristics, tensile properties and morphology of the compounds were investigated. Results indicated that slight changes in curing time (t90), and scorch time (tS2) of the compounds with the incorporation of chitosan. An increment is observed in the maximum torque, tensile modulus and durometer hardness of the compounds while tensile strength and elongation at break declines with chitosan loading.

Influence of bis(triethoxysilylpropyl) tetrasulfide amount on the properties of silica-filled epoxidized natural rubber-based composites

2016 ◽  
Vol 23 (4) ◽  
pp. 357-362
Author(s):  
Omar A. Al-Hartomy ◽  
Ahmed A. Al-Ghamdi ◽  
Said A. Farha Al Said ◽  
Nikolay Dishovsky ◽  
Mihail Mihaylov
Keyword(s):  
Natural Rubber ◽  
Dynamic Properties ◽  
Epoxidized Natural Rubber ◽  
Rubber Matrix ◽  
Coupling Agents ◽  
Silane Coupling Agents ◽  
Rubber Composites ◽  
Rubber Compounds ◽  
Curing Characteristics ◽  
Epoxy Groups

AbstractThe aim of the present article is to investigate the influence of the amount of bis(triethoxysilylpropyl) tetrasulfide on the curing characteristics and mechanical and dynamic properties of rubber composites based on epoxidized natural rubber (Epoxyprene 50) filled with 70 phr silica. The obtained results showed that although the interaction between the epoxy groups of epoxidized natural rubber and the silanol groups of silica through hydrogen bonds improves the dispersion of filler in the rubber matrix, the presence of silane coupling agents is necessary to obtain rubber compounds and vulcanizates with good vulcanization characteristics and mechanical and dynamic properties.

Effect of Mesogenic Organic Salts on Vulcanization and Physical Properties of Natural Rubber Compounds

2012 ◽  
Vol 1483 ◽  
Author(s):  
F. Avalos ◽  
M. Tellez-Rosas ◽  
M.E. Castañeda-Flores ◽  
F. J. Martínez-Casado ◽  
J. A. Rodríguez-Cheda ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Rheological Behavior ◽  
Solid Phase ◽  
Tensile Modulus ◽  
Rubber Matrix ◽  
Organic Salts ◽  
Rubber Compounds ◽  
Reinforcing Fillers ◽  
Condis Phase ◽  
Cation Size

ABSTRACTThe effect of mesogenic organic salts as reinforcing fillers for natural rubber has been investigated. The influence of cation size (thallium and sodium) and organic chain length (thallium (I) pentanoate and dodecanoate) on the vulcanization parameters, physical and mechanical characteristics and rheological behavior has also been analyzed. In general, the maximum torque of the vulcanizates increases in the presence of the salts and is clearly manifested in a sensible increase in tensile modulus and strength of the composites. The reinforcing effect of these salts is noticeable in the natural rubber matrix. The thallium (I) salts are more effective reinforcements than the sodium salt, and the length of the organic chain hardly has any influence on the mechanical properties. The composites based on the thallium (I) dodecanoate salt show a very peculiar rheological behavior with a “plateau” in the G’ and G” vs temperature graphics which is related with solid phase I, existing between 83.5 ºC and 127 ºC, characterized as a plastic condis phase. This issue is especially interesting for the fabrication of devices such as sensors to control, for instance, the security (resistance of a material) as a function of temperature.

Excimer Laser Treatment of Nylon Fibers for Improved Adhesion to Vulcanized Natural Rubber

2020 ◽  
Author(s):  
Erol Sancaktar ◽  
Satilmis Basan
Keyword(s):  
Natural Rubber ◽  
Excimer Laser ◽  
Bonding Strength ◽  
Laser Pulses ◽  
Test Method ◽  
Rubber Matrix ◽  
Uv Laser ◽  
Synthetic Fibers ◽  
Pull Out ◽  
Laser Treatments

Abstract Cords made of steel, nylon or polyester are important reinforcement components used in tire industry. The bond strength between the cords and the rubber matrix is closely related to the surface properties of the cord fibers. Previous research revealed Ultraviolet (UV) laser-induced characteristic topography on synthetic fibers after irradiation, which is considered by us as an advantageous factor in developing bonding strength between fiber-rubber composites. We applied various UV laser treatments on the surfaces of nylon fibers in order to obtain similar topographic features. Adhesion is affected by the valleys and peaks that form on the surface of the fibers by laser radiation. In this study, nylon cords were irradiated with different number of UV pulses using an excimer laser to understand the effect of the laser beam on nylon fiber-rubber adhesion. A fiber pull-out test method developed by our research group for bonding strength of nylon cord fibers to carbon black filled and vulcanized natural rubber was utilized in pull-out configuration. The results showed that the maximum pull-out load was reached at 300 laser pulses and then decreased.

scholarly journals Experimental and Modelling Study of the Effect of Adding Starch-Modified Natural Rubber Hybrid to the Vulcanization of Sorghum Fibers-Filled Natural Rubber

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3017
Author(s):  
Mochamad Chalid ◽  
Yuli Amalia Husnil ◽  
Santi Puspitasari ◽  
Adi Cifriadi
Keyword(s):  
Natural Rubber ◽  
Hybrid Material ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Rubber Matrix ◽  
Sem Images ◽  
Rubber Blends ◽  
Rubber Compounds ◽  
Different Temperatures ◽  
Torque Analysis

Natural rubber-starch copolymer hybrid obtained from our laboratory was used as an additive for rubber compound. In this work, the effect of adding this hybrid material to vulcanization kinetics of sorghum fibers-filled natural rubber was studied. The rubber compounds were added with hybrid material at various loadings, i.e., zero to two phr and thus cured at three different temperatures, i.e., 130, 140, and 150 °C. The molecular behaviors due to the hybrid addition were investigated by Fourier-Transform Infrared (FTIR) spectroscopy. The rheological phenomena of the rubber compounds were studied by performing torque analysis in moving die rheometer. The obtained data were utilized to develop the thermodynamic modeling. The compatibility of sorghum fibers-natural rubber blends in the presence of starch-modified natural rubber were characterized using Field Emission Scanning Electron Microscope (FE-SEM). FTIR results show noticeable changes in the peak intensity of particular functional groups from rubber and natural fiber as evidence of molecular interaction enhancements between rubber and natural fibers caused by incorporating the starch-modified natural rubber coupling agent to rubber-natural fiber blends. The curing time for these blends was reduced with lower required activation energy. SEM images show no visible gaps in morphology between natural rubber and the filler indicating that the addition of hybrid material to the blends also improves the compatibility between the fibers and the rubber matrix.

An alternative antioxidant for sulfur-vulcanized natural rubber: Henna

2018 ◽  
Vol 51 (5) ◽  
pp. 440-456 ◽  
Author(s):  
Şehriban Öncel ◽  
Begüm Kurtoğlu ◽  
Bağdagül Karaağaç
Keyword(s):  
Natural Rubber ◽  
Physical And Mechanical Properties ◽  
Rubber Matrix ◽  
Synthetic Antioxidants ◽  
Oxidative Aging ◽  
Rubber Compounds ◽  
Sulfur Vulcanization ◽  
Short And Long Term ◽  
Temperature Scanning

Oxidative aging of natural rubber (NR) leads to the deterioration in the physical and mechanical properties. Using various antioxidants during compounding is a common way to improve the aging resistance of NR. The most widespread used antioxidants are phenolic and amine-based synthetic antioxidants and 2,2,4-trimethyl-1,2-dihydroquinoline in rubber industry. However, synthetic antioxidants cause some environmental problems during their production and tend to be replaced by natural alternatives. In this study, henna has been evaluated as a natural antioxidant in NR-based rubber compounds for efficient and conventional sulfur vulcanization systems. Performance of henna was evaluated in terms of rheological, mechanical, aging, and temperature scanning stress-relaxation properties of the compounds. It has been concluded that henna could be used as an alternative antioxidant for sulfur vulcanization of natural rubber matrix, compensating little deteriorations in vulcanizate properties. Short- and long-term performances of henna were also found to be related to vulcanization system.

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