Effects of Natural Rubber Origin on Mechanical Properties of Rubber Compound in the Presence of Natural and Commercial Antioxidants

2013 ◽  
Vol 747 ◽  
pp. 703-706 ◽  
Author(s):  
N.H.H. Shuhaimi ◽  
Nadras Othman ◽  
Hanafi Ismail ◽  
S. Sasidharan
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Aging Process ◽  
Rubber Compound ◽  
Tear Strength ◽  
End Products ◽  
Reasonable Result ◽  
Before And After ◽  
Tear Properties ◽  
Different Origin

Different origin of rubber gives different effect towards the properties of end products. In this paper, effect of natural rubber (NR) origin on tensile properties and tear strength before and after aging for 4 and 7days were investigated in the presence of natural antioxidant (NA). Effectiveness of NA in different NR origin was compared with commercial antioxidants (TMQ). The NR from Malaysia (SMR CV60), Thailand (STR 5L), Vietnam (SVR 3L) and Cambodia (SCR L) were used in this study and cured using Semi-EV. For tensile and tear strength before aging process, STR 5L / NA shows the highest result followed by SVR 3L, SCR L and SMR CV60. This is due to higher molecular weight of STR 5L compound. But after aging for 4 and 7 days, SMRCV 60 has shown the highest percentage of retention for tensile and tear strength which indicated the lowest breakage of crosslink. From the results of tensile and tear properties, it is verified that different NR origin compound with NA vulcanizate gives reasonable result which are comparable to NR with TMQ vulcanizates.

Mechanical Behavior of Polystyrene-Grafted Natural Rubber/Natural Rubber Blend: Effect of Polystyrene Grafting Percentage

2017 ◽  
Vol 751 ◽  
pp. 308-313 ◽  
Author(s):  
Tarakol Hongkeab ◽  
Peerapan Dittanet
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Reaction Times ◽  
Rubber Compound ◽  
Tear Strength ◽  
Emulsion Copolymerization ◽  
Rigid Chain ◽  
Transmission Electron ◽  
Core Shell Structure

Polystyrene-grafted natural rubber (PS-GNR) at various graft levels was evaluated to improve mechanical properties of natural rubber (NR). PS-GNR was synthesized by emulsion copolymerization at 60°C at different reaction times between 15 and 360 mins to control the grafting levels of PS in the PS-GNR co-polymer. The resultant PS-GNR co-polymers were then blended into NR latex. The vulcanized NR compounds were investigated for the effect of PS grafting percentage in PS-GNR/NR compounds on mechanical properties, including tensile, tear strength and hardness. A core-shell structure was revealed with PS encapsulating the NR core via transmission electron microscopy. The polystyrene grafting percentage was determined to be 12.7%, 17.1%, 22.1% and 23.6% for polymerization times of 15 min, 60min, 120min, and 360 min, respectively. Addition of PS-GNR into NR exhibited biphasic behavior, resulting in a decrease in the tensile strength and tear strength. With further increase in grafting percentage of PS, the tensile strength and tear strength continues to decrease. The rigid chain of PS grafted onto NR surface reduced the elasticity of NR chain resulting in lower tear strength and the tensile strength. Fracture surface revealed a decrease in ductility of material with increasing grafting percentage of PS. On the other hand, modulus and hardness of PS-GNR/NR compounds were found to increase with increasing grafting percentage of PS. The addition of PS-GNR to rubber compound had shown an impact on dynamic behavior. With further increase in grafting percentage of PS in PS-GNR, an enhancement of storage modulus of rubber compound was clearly observed.

Sunlight exposure: the effects on the performance of paragliding fabric

2018 ◽  
Vol 69 (05) ◽  
pp. 381-389
Author(s):  
MENGÜÇ GAMZE SÜPÜREN ◽  
TEMEL EMRAH ◽  
BOZDOĞAN FARUK
Keyword(s):  
Mechanical Properties ◽  
Aging Process ◽  
Air Permeability ◽  
Sunlight Exposure ◽  
Test Results ◽  
Coating Materials ◽  
Strength Tests ◽  
Before And After ◽  
The Relationship ◽  
Dark Blue

This study was designed to explore the relationship between sunlight exposure and the mechanical properties of paragliding fabrics which have different colors, densities, yarn counts, and coating materials. This study exposed 5 different colors of paragliding fabrics (red, turquoise, dark blue, orange, and white) to intense sunlight for 150 hours during the summer from 9:00 a.m. to 3:00 p.m. for 5 days a week for 5 weeks. Before and after the UV radiation aging process, the air permeability, tensile strength, tear strength, and bursting strength tests were performed. Test results were also evaluated using statistical methods. According to the results, the fading of the turquoise fabric was found to be the highest among the studied fabrics. It was determined that there is a significant decrease in the mechanical properties of the fabrics after sunlight exposure. After aging, the fabrics become considerably weaker in the case of mechanical properties due to the degradation in both the dyestuff and macromolecular structure of the fiber

Mechanochemical Devulcanization of Vulcanized Gum Natural Rubber

2005 ◽  
Vol 21 (3) ◽  
pp. 183-199
Author(s):  
G.K. Jana ◽  
C.K. Das
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Three Dimensional ◽  
Elongation At Break ◽  
Tear Strength ◽  
Vulcanized Rubber ◽  
Dimensional Network ◽  
Polymeric Chains ◽  
Cure Time

De-vulcanization of vulcanized elastomers represents a great challenge because of their three-dimensional network structure. Sulfur-cured gum natural rubbers containing three different sulfur/accelerator ratios were de-vulcanized by thio-acids. The process was carried out at 90 °C for 10 minutes in an open two-roll cracker-cum-mixing mill. Two concentrations of de-vulcanizing agent were tried in order to study the cleavage of the sulfidic bonds. The mechanical properties of the re-vulcanized rubber (like tensile strength, modulus, tear strength and elongation at break) were improved with increasing concentrations of de-vulcanizing agent, because the crosslink density increased. A decrease in scorch time and in optimum cure time and an increase in the state of cure were observed when vulcanized rubber was treated with high amounts of de-vulcanizing agent. The temperature of onset of degradation was also increased with increasing concentration of thio-acid. DMA analysis revealed that the storage modulus increased on re-vulcanization. From IR spectroscopy it was observed that oxidation of the main polymeric chains did not occur at the time of high temperature milling. Over 80% retention of the original mechanical properties (like tensile strength, modulus, tear strength and elongation at break) of the vulcanized natural rubber was achieved by this mechanochemical process.

Characterization of Snap-On Calf Nipple Product and Development of its Compound Formulation Based on Natural Rubber

2017 ◽  
Vol 744 ◽  
pp. 282-287
Author(s):  
Sarawut Prasertsri ◽  
Sansanee Srichan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Calcium Carbonate ◽  
Carbon Black ◽  
Natural Rubber ◽  
Soxhlet Extraction ◽  
Rubber Compound ◽  
Rubber Compounds ◽  
Rubber Component

This research aimed to develop the formulation of natural rubber filled with carbon black, silica and calcium carbonate for rubber calf nipple application. The reverse engineering was performed on the calf nipple product to analyze the rubber type and component by using Soxhlet extraction, thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) techniques. Furthermore, mechanical properties were examined to act as benchmark for the rubber compound design. The results showed that rubber component in the nipple product was natural rubber, whereas two filler types revealed as carbon black and calcium carbonate with 10 and 35 of the total weight. In addition, rubber nipple showed the hardness of 46±1 Shore A and tensile strength of 5.3±0.60 MPa. From the investigation of the properties of developed rubber compounds in this work, it was found that the mechanical properties depended on type and content of filler. The required mechanical properties of vulcanizates were achieved at 20 phr of carbon black (N330), 20 phr of silica and 120 phr of calcium carbonate.

scholarly journals Correlation between the Crosslink Characteristics and Mechanical Properties of Natural Rubber Compound via Accelerators and Reinforcement

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2020 ◽  
Author(s):  
Do Young Kim ◽  
Jae Woo Park ◽  
Dong Yun Lee ◽  
Kwan Ho Seo
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Modern Society ◽  
Processing Conditions ◽  
Rubber Compound ◽  
Interaction Theory ◽  
Equilibrium Swelling ◽  
Mechanical Optimization ◽  
Insight Into ◽  
Rubber Filler

The extreme elasticity and reversible deformability of rubber, which is one of the most versatile polymers in modern society, is dependent on several factors, including the processing conditions, curing system, and types of additives used. Since the rubber’s mechanical properties are influenced by the existing structural crosslinks, their correlation with the crosslink characteristics of rubber was investigated using the equilibrium swelling theory of the Flory–Rehner equation and the rubber–filler interaction theory of the Kraus equation. Herein, we examined whether the accelerator and reinforcement agent quantitatively contributed to chemical cross-linkages and rubber–filler interaction. In conclusion, the accelerator content supported the chemically crosslinked structures of the monosulfides and the disulfides in natural rubber (NR). Additionally, these results demonstrated that the mechanical properties and the thermal resistance of NR were dependent on the crosslink characteristics. The findings of this study provide an insight into the development and application of NR products for the mechanical optimization of rubber-based products.

scholarly journals Influence of Carbon Black and Silica Filler on the Rheological and Mechanical Properties of Natural Rubber Compound

2015 ◽  
Vol 16 ◽  
pp. 258-264 ◽  
Author(s):  
Ika Maria Ulfah ◽  
Riastuti Fidyaningsih ◽  
Sri Rahayu ◽  
Diah Ayu Fitriani ◽  
Dita Adi Saputra ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
Natural Rubber ◽  
Rubber Compound ◽  
Silica Filler

Influences of Particle Sizes on Properties of Natural Rubber/Waste Ground Rubber Powders Blends

2013 ◽  
Vol 773 ◽  
pp. 668-672
Author(s):  
Jun Liang Liu ◽  
Ping Liu ◽  
Xiao Qiang Tang ◽  
Dong Zeng ◽  
Xing Kai Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Chemical Activation ◽  
Cross Linking ◽  
Particle Sizes ◽  
Elongation At Break ◽  
Tear Strength ◽  
Rubber Waste ◽  
Ground Rubber

In this paper, the blends of natural rubber with waste ground rubber powders have been prepared by mechano-chemical activation method. The influences of particle sizes on both processing performances and mechanical properties have been investigated. The results indicated that: the blends with waste ground rubber powders of smaller particle sizes approached to higher surface tensile and easily mechano-chemical activation, which led to the formation of complete homogenous re-vulcanization cross-linking structure and resulted in the improvements of the whole performances of the final products. The tensile strength, the elongation at break and tear strength approached to the highest value of 20.7MPa, 530% and 33.0 kN/m as the 100mesh waste ground rubber powders were used as the starting materials.

Study on Mechanical Properties Aging of Spray Pure Polyurea for Hydraulic Concrete Protection

2011 ◽  
Vol 374-377 ◽  
pp. 1325-1329 ◽  
Author(s):  
Wei Bo Huang ◽  
Jia Yu Xiang ◽  
Ping Lv ◽  
Xin Mao Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Development Trend ◽  
Elongation At Break ◽  
Tear Strength ◽  
Hydraulic Concrete ◽  
Before And After ◽  
Ultraviolet Ray ◽  
Resistance Performance

Researches of spray pure polyurea technology for hydraulic concrete protection in water conservancy facilities to ensure long term security operation has a great significance. With an emphasis upon mechanical properties and surface morphology of spray pure polyurea coatings comparing before and after aging by means of the artificial accelerated xenon arc lamp(AAXAL) and scanning electron microscope(SEM) in this paper. Besides, the dry-wet circulation resistance performance of coatings wre analyzed through experiment. It is shown that tensile strength, elongation at break and tear strength of coatings increased by 0.2%, 0.5% and 1.7% respectively after AAXAL aging 720h. By contrast, after aging 3000h the results were 22.6%, 3.8% and 17.4% respectively, the tendency of increasing at first and then reducing can be obtained. The mechanical properties reduced slightly for adding defects of coating surface after aging, however, the resistance performance of ultraviolet ray was excellent. The similar development trend of mechanical properties were gained from dry-wet circulation experiment. After aging 200 cycles, the tensile strength and tear strength descended by 4.1% and 1.7% severally but the elongation at break ascended by 5.0%. In a word, it is suggested that the aging of coatings were negligible in dry-wet circulation in short term.

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