Aromatic and Epoxidised Oil Curing and Rebound Resilience Characteristic and their Humidity Effect of Hardness on NR Vulcanizates

2013 ◽  
Vol 812 ◽  
pp. 138-144 ◽  
Author(s):  
Mohamed Rahmah ◽  
Wan Zain Norazira ◽  
Shafie Nur Ashyikin ◽  
Mohd Nurazzi Norizan
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Room Temperature ◽  
Rubber Compound ◽  
Humidity Effect ◽  
Humidity Level ◽  
Cure Time ◽  
Humidity Chamber ◽  
Overall Performance ◽  
Natural Rubber Vulcanizates

Recently, aromatic oil (AO) is one of the substances that is typically used as a processing aid especially for high filler loadings in formulating rubber compound. Aromatic oil has disadvantages in that, it is hazardous to environment, toxic and has been labeled as carcinogenic. In this research, an epoxidised oil (EO) and aromatic oil were used to investigate the effect incorporation of oil onto the SBR/NR natural rubber vulcanizates (NR). From the result obtained, EO showed shorter cure time and scorch time as the oil loading were increased up to 20 pphr of EO. Physical properties such as hardness and rebound resilience of NR/EO vulcanisate were also investigated upon exposure to different humidity level in humidity chamber. At room temperature, the hardness of EO loading onto the SBR/NR vulcanisate is lower than AO loadings. Hardness was slightly decreased with increasing rate of humidity. There is great difference in hardness and rebound resilience values between AO and EO. Both hardness and rebound resilience were not affected by humidity. This implies the existence of good filler interaction with EO and rubber which do not impart changes in the hardness and resilience properties of rubber compound. Epoxidised oil has great promising potential to replace the carcinogenic aromatic oil as it has good overall performance and renewable in nature .

Cure Characteristics and Physical Properties of Imperata cylindrica Activated Carbon Filled SMR L Compounding

2015 ◽  
Vol 815 ◽  
pp. 44-48
Author(s):  
M.H. Fatin ◽  
N.Z. Noriman ◽  
Kamarudin Husin ◽  
M.Z. Salihin ◽  
N.R. Munirah ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Natural Rubber ◽  
Physical Properties ◽  
Crosslink Density ◽  
Filler Loading ◽  
Rubber Compound ◽  
Maximum Torque ◽  
Cure Characteristics ◽  
Cure Time ◽  
Minimum Torque

The potential of activated carbon as a filler in rubber compound has been reviewed .Cure characteristics and physical properties ofImperataCylindricaactivated carbon filled natural rubber of Standard Malaysian Rubber (SMR L) were studied. SMR L was used as the elastomer and the composition of filler loading were varied from 0-50 parts per hundred rubber (phr). A semi-efficient vulcanization system was used throughout the study. The cure characteristics of the rubber compound was determined by using rheometer. The samples of hardness and resilience were measured by durometer shore A and Wallace Dunlop Tripsometer. Cure characteristics showed that cure time, t90and scorch time,t2increased as increased filler loading which indicate poor interaction between rubber and filler which slow down the vulcanization time. Minimum torque,MLand maximum torque,MHincreased as increased filler loading due to the low processability of the SMR L compounds. Crosslink density and hardness exhibit increment as increased filler loading due to increase rigidity of the SMR L compounds. The resilience will decrease correspondingly as increased in rigidity of the compounds.

Characterization of Ground Rubber Tire and its Effect on Natural Rubber Compound

2000 ◽  
Vol 73 (5) ◽  
pp. 902-911 ◽  
Author(s):  
Amit K. Naskar ◽  
S. K. De ◽  
A. K. Bhowmick ◽  
P. K. Pramanik ◽  
R. Mukhopadhyay
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Rubber Compound ◽  
Rubber Tire ◽  
Ground Rubber

Abstract Ground rubber tire (GRT) particles of different sizes were characterized and the effect of these particles in a natural rubber (NR) compound was studied. It is found that smaller particles contain less polymer, but have higher amounts of fillers and metals with respect to polymer. NR compound containing smaller GRT particles shows better physical properties, but poorer aging characteristics.

Oxidative Aging of Natural Rubber Vulcanizates. Part III. Crosslink Scission in Monosulfidic Networks

1969 ◽  
Vol 42 (3) ◽  
pp. 924-935 ◽  
Author(s):  
T. Colclough ◽  
J. I. Cunneen ◽  
G. M. C. Hrggins
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Chemical Structure ◽  
Spectroscopic Methods ◽  
Chemical Probes ◽  
Conjugated Diene ◽  
Strain Measurements ◽  
Oxidative Aging ◽  
Tert Butyl Hydroperoxide ◽  
Natural Rubber Vulcanizates

Abstract A natural rubber vulcanizate containing almost entirely monosulfidic crosslinks was oxidized in oxygen and with tert-butyl hydroperoxide. The changes in physical properties due to oxidation were followed by stress—strain measurements, and the changes in chemical structure were investigated with chemical probes, and by spectroscopic methods. The results show that when the oxidized vulcanizates are heated at 75° C, the monosulfidic crosslinks are broken, that crosslinks containing two sulfur atoms are formed, and that conjugated diene and triene structures are introduced into the main polyisoprene chains.

HXNBR Coating for Improving Aging Resistance of Natural Rubber Products

2006 ◽  
Vol 79 (4) ◽  
pp. 553-560 ◽  
Author(s):  
Rani Joseph
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Room Temperature ◽  
Oxidative Degradation ◽  
Thin Coating ◽  
Oil Resistance ◽  
Aging Resistance ◽  
Natural Rubber Vulcanizates ◽  
Good Heat ◽  
Accelerator System

Abstract HXNBR (Hydrogenated Carboxylated Nitrile Rubber) has very good heat ageing resistance and oil resistance. A novel accelerator system is designed to bring about the vulcanization of HXNBR at room temperature. The room temperature cured samples showed good mechanical properties equivalent to those of high (150 °C) temperature cured samples. Natural rubber vulcanizates are highly prone to oxidative and ozone degradation. The oil resistance of natural rubber vulcanizates is also very low. The oil resistance, ozone and oxidative degradation resistance of natural rubber vulcanizates are considerably improved by placing a thin coating of HXNBR over it.

Curing Characteristics and Mechanical Properties of Rattan Filled Natural Rubber Compounds

2011 ◽  
Vol 471-472 ◽  
pp. 845-850 ◽  
Author(s):  
Komethi Muniandy ◽  
Hanafi Ismail ◽  
Nadras Othman
Keyword(s):  
Natural Rubber ◽  
Tensile Modulus ◽  
Filler Loading ◽  
Morphological Properties ◽  
Rubber Matrix ◽  
Rubber Compound ◽  
Curing Characteristics ◽  
Roll Mill ◽  
Cure Time ◽  
Rubber Filler

Rattan for its potential as a new type of filler was investigated in natural rubber (NR) compounds. Natural rubber (NR) compounds were prepared by the incorporation of rattan at different loadings into a natural rubber matrix with a laboratory size two roll mill. The effect of rattan loading as filler on curing characteristics, tensile properties, morphological properties using scanning electron microscopy (SEM) and rubber–filler interaction of rattan filled natural rubber compound were studied in the filler loading range of 0 to 30 phr. The results indicate that the scorch time (ts2) and cure time (t90) shorten with increasing filler loading, whereas the maximum torque (MH) showed an increasing trend. As the filler loading increases, the tensile strength and elongation at break decreases whilst tensile modulus; stress at 100 % elongation and stress at 300 % elongation increased. The rubber filler interactions of the rubber compound decreased with increasing filler loading. SEM studies indicate that the increasing rattan loading weakens the rubber-rattan interactions.

Recycled Cigarette Filter as Reinforcing Filler for Natural Rubber

2014 ◽  
Vol 705 ◽  
pp. 39-43 ◽  
Author(s):  
Mun Kou Lai ◽  
Hiu Hong Teo ◽  
Jien Ye Lee
Keyword(s):  
Tensile Test ◽  
Natural Rubber ◽  
Cellulose Acetate ◽  
Mechanical Testing ◽  
Rubber Compound ◽  
Cigarette Filter ◽  
Tear Strength ◽  
Nicotine Content ◽  
Cure Time ◽  
Reinforcing Filler

Natural rubber is highly resilient and possesses many outstanding characteristics but inferior in aspects like modulus and hardness. This however can be improved by reinforcement, forming a composite. The rubber compound in this study was prepared according to the ASTM D3184 standards and reinforced using cellulose acetate (CA) from recycled cigarette filter, partly as an effort to reduce the amount of waste. Moreover, cigarette filter is highly toxic due to the nicotine content thus requires care when is recycled. From the rheological and mechanical testing conducted i.e. scorch and cure time, torque, tensile test and tear strength, it seems to indicate a small amount of up 4 phr (parts per hundred rubber) of CA, is beneficial in improving the properties of the rubber compound.

EFFECT OF CURE EFFICIENCY ON PROPERTIES OF GUM AND BLACK FILLED NATURAL RUBBER VULCANIZATES

2011 ◽  
Vol 84 (2) ◽  
pp. 229-242 ◽  
Author(s):  
Gary R. Hamed ◽  
Kanoktip Boonkerd
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Cure Time ◽  
Cracking Pattern ◽  
Natural Rubber Vulcanizates ◽  
Scanning Electron ◽  
Fracture Specimens ◽  
Strength Effect

Abstract Effects of the sulfur cure efficiency on the reversion behavior and the normal and edge-cut tensile strength of gum and black filled natural rubber (NR) vulcanizates were studied. N, N-dicyclohexyl-2-benzothiazole sulfenamide (DCBS) was used as an accelerator. A series of five vulcanizates with high to low cure efficiencies was prepared by increasing the sulfur (S) to DCBS ratios within the range of 0.26–6.66. All vulcanizates were formulated to have the same crosslink density. The degree of reversion (%) calculated from cure curves of gum and black filled NR at 20 min above the cure time (tc100) passed through maximum with decreasing cure efficiencies. For both gum and black filled NR, the highest degree of reversion (%) was observed at the S/DCBS ratio of 1.17. The normal tensile strengths of gum and black filled NR were directly proportional to the cure efficiency. For gum NR vulcanizates, the edge-cut tensile strength was markedly influenced by cure efficiency. Similar to the normal tensile strength, the gum NR vulcanizates cured with the lowest cure efficiency showed the lowest edge-cut tensile strength. Effect of the cure efficiency on the edge-cut tensile strength was less in the case of black filled NR vulcanizates. However, the black filled NR vulcanizates cured with the lowest cure efficiency also showed the lowest edge-cut tensile strength. The cut tip characteristics of the fracture specimens were investigated using scanning electron microscopy. The gum specimens showed only the simple lateral cracking pattern, while all black filled specimens showed the longitudinal cracking pattern. Four different cracking patterns of the black filled specimens were identified. The distribution of cracking patterns depended strongly on the size of precut and the cure efficiency.

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