Effect of Ingredient Loading on Vulcanization Characteristics of a Natural Rubber Compound

2015 ◽  
Vol 1125 ◽  
pp. 50-54 ◽  
Author(s):  
Bryan B. Pajarito
Keyword(s):  
Natural Rubber ◽  
Raw Materials ◽  
Fractional Factorial ◽  
High Loading ◽  
Rubber Compound ◽  
Cure Rate ◽  
Used Oil ◽  
Rubber Compounds ◽  
Cure Time ◽  
Viscous Torque

Rheometric properties of rubber compounds are usually monitored with time during the course of vulcanization at constant temperature. The measured vulcanization characteristics of rubber compound are used for quality control and evaluation of raw materials and product formulations. With the high number of ingredients used in typical formulations, it is important to identify ingredients which significantly affect the vulcanization characteristics of a rubber compound. This study reports the vulcanization characteristics of a natural rubber compound at 60 °C as function of ingredient loading. Rubber sheets are compounded according to a 212-8 fractional factorial design of experiment, where ingredients are treated as factors varied at low and high loadings. Vulcanization curves, which are time plots of elastic torque S’, viscous torque S”, and tan δ = S”/S’, are measured for each rubber sheet using a moving die rheometer. The following responses are then determined from the vulcanization curves for data analysis: minimum elastic torque ML, maximum elastic torque MH, torque difference ∆S = MH – ML, scorch time ts1, cure time t’90, cure rate index CRI = 100/ (t’90 – ts1), S” and tan δ values at ML and MH. Analysis of variance (ANOVA) shows used oil to be the main ingredient affecting vulcanization of the natural rubber compound (ML, MH, ∆S, ts1, S” at ML and MH), followed by sulfur (MH, ∆S, CRI), calcium carbonate CaCO3 (S” at ML, tan δ at MH) and diphenylguanidine DPG (ts1). High loading of used oil lowers the elastic and viscous response of the rubber compound, while increases the time for scorch. Increased loading of sulfur significantly enhances the elastic torque and cure rate of the compound. High loading of CaCO3 improves the viscous response, while DPG significantly shortens the scorch time of the rubber compound.

scholarly journals PENGARUH PENAMBAHAN ALKANOLAMIDA TERHADAP KARAKTERISTIK PEMATANGAN DAN KEKERASAN VULKANISAT KARET ALAM BERPENGISI KAOLIN

2013 ◽  
Vol 2 (4) ◽  
pp. 38-42
Author(s):  
Indah M.S. Sitorus ◽  
Yudha Widyanata ◽  
Indra Surya
Keyword(s):  
Natural Rubber ◽  
Crosslink Density ◽  
Palm Stearin ◽  
Rubber Compound ◽  
Cure Characteristics ◽  
Rubber Compounds ◽  
Cure Time

By using a semi-efficient sulphur accelerated vulcanization system, an investigation of the effect of  alkanolamide on cure characteristics and hardness  properties of kaolin-filled natural rubber compounds was carried out. Alkanolamide was synthesized  from Refined Bleached Deodorized Palm Stearin (RBDPS) and diethanolamine. Alkanolamide was incorporated into the kaolin filled-natural rubber compound at 1.0; 3.0; 5.0 and 7.0 Parts per-Hundred RubbeR (phr). It was found that alkanolamide gave shorter scorch time and cure time. Alkanolamide also exhibited higher torque different,  crosslink density, and hardnessup to 5.0 phr and then decreased with further increasing the loading of alkanolamide.

Effect of Ingredient Loading on Water Transport Properties of a Vulcanized Natural Rubber Compound

2015 ◽  
Vol 1125 ◽  
pp. 55-59 ◽  
Author(s):  
A. Ananoria ◽  
Bryan B. Pajarito
Keyword(s):  
Natural Rubber ◽  
Transport Properties ◽  
Water Transport ◽  
Uptake Rate ◽  
Gravimetric Method ◽  
Fractional Factorial ◽  
Rubber Compound ◽  
Used Oil ◽  
Initial Uptake Rate ◽  
Water Transport Properties

Water transport properties of a vulcanized natural rubber compound are studied as function of ingredient loading using gravimetric method at 800C. Rubber sheets are compounded according to a fractional factorial design of experiment, where ingredients are treated as factors varied at two levels of loading. Weight change during immersion in water is monitored. The maximum uptakes are determined from the sorption curves which showed two distinct slopes of which two uptake rates are estimated. Analysis of variance shows that high loadings of sulfur, asphalt, and used oil significantly increase the maximum uptake and first uptake rate while only sulfur and asphalt significantly increase the second uptake rate. On the other hand, high loadings of reclaimed rubber, calcium carbonate (CaCO3), mercaptobenzothiazole (MBT) significantly decrease the maximum amount of water uptake. Similarly, high loading of mercaptobenzothiazole disulfide (MBTS) significantly decrease the initial uptake rate while high loadings of reclaimed rubber, CaCO3, kaolin clay, and MBT decrease the final uptake rate of rubber compounds.

Calophyllum Inophyllum Oil as Plasticizer in Natural Rubber Compounds

2009 ◽  
Vol 25 (2) ◽  
pp. 113-128 ◽  
Author(s):  
P. Raju ◽  
V. Nandanan ◽  
Sunil K.N. Kutty
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Thermal Studies ◽  
Calophyllum Inophyllum ◽  
Compression Set ◽  
Peak Rate ◽  
Rubber Compounds ◽  
Cure Time ◽  
Calophyllum Inophyllum Oil ◽  
Control Compound

Mechanical properties and the thermal degradation characteristics of natural rubber compounds with calophyllum inophyllum oil were compared to that of the control compound containing naphthenic oil. The compounds containing calophyllum inophyllum oil showed improved tensile strength, tear strength, modulus, compression set, abrasion resistance and resilience. Cure time was higher than the naphthenic oil mixes. Thermal studies showed an increase of 8 °C in the temperature of initiation of degradation and an increase of 6 °C in temperature at which the peak rate of degradation occurred. The peak rate of degradation was comparable to the control mix containing naphthenic oil.

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.

The Effect of Second Filler on Cure Characteristic and Mechanical Properties of Si-69 Treated Precipitate Silica/NR Composite

2009 ◽  
Vol 79-82 ◽  
pp. 2183-2186 ◽  
Author(s):  
Chanchai Thongpin ◽  
C. Sripetdee ◽  
N. Papaka ◽  
N. Pongsathornviwa ◽  
Narongrit Sombatsompop
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fly Ash ◽  
Rubber Compound ◽  
Maximum Torque ◽  
Elongation At Break ◽  
Rubber Vulcanizate ◽  
Rubber Compounds ◽  
Cure Time ◽  
Cure Characteristic

Silica has been widely used as non-black reinforcing filler, however, the filler-filler interaction has been an important issue. Cure characteristic and mechanical properties of the rubber compound and rubber vulcanizate were affected both by filler-rubber interaction and filler-filler interaction. There have been, presently, a number of natural fillers which are also used as fillers for the rubber, i.e. fly ash, sawdust and zeolite. This work therefore will study the effect of second filler added into the 13% Si-69 treated precipitate silica (PSi) filled natural rubber compounds. It was revealed that the scorch and cure time of the rubber compound increased with the content of treated PSi. This was the effect of excess of the silane treated onto PSi which would agglomerate and form the cluster of polysiloxane and would then be able to absorb vulcanizing accelerator resulting in extending the scorch and cure time of the rubber compounds. However, this effect was over ruled with the reinforcing effect as could be seen by the increasing, with the contents of PSi, of maximum torque and mechanical properties of the vulcanizates. The NR compounded with treated PSi content of 20 phr selected to study the effect of excess silane on the cure characteristic of hybrid fillers NR composite. The addition of sawdust led to longer scorch time and cure time but not much change of the maximum torque. As expected, the modulus of the rubber vulcanizate increased with the sawdust content whereas the tensile strength and elongation at break decreased with the sawdust content. The incorporation of zeolite could accelerate the cure reaction therefore both scorch time and cure time decreased. The maximum torque also increased with the content of zeolite. Both modulus and tensile strength increased with the content of the zeolite whereas elongation at break tended to be unchanged. In the case of using fly ash as the second filler, the cure time tended to be unchanged. However, the maximum torque tended to be increased with the content of fly ash. It was found that the modulus, tensile strength increased but elongation at break decreased. Interestingly, the excess of Si-69 used effect pronouncedly for the addition of zeolite and fly ash cases as the excess silane could promote the interaction between fillers surface and rubber molecule accept for sawdust

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 .

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.

scholarly journals EFFECT OF EPOXIDIZED NATURAL RUBBER AS A COMPATIBILIZER IN SILICA-FILLED STYRENE BUTADIENE RUBBER COMPOUND

2014 ◽  
Vol 3 (2) ◽  
pp. 1-4
Author(s):  
Indra Surya ◽  
Siswarni MZ
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Tensile Modulus ◽  
Epoxidized Natural Rubber ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Rubber Compound ◽  
Cure Rate ◽  
Styrene Butadiene ◽  
Rubber Filler

By using a semi-efficient vulcanization system, the effect of Epoxidized Natural Rubber (ENR) as a compatibilizer in silica-filled Styrene Butadiene Rubber (SBR) compound was carried out. The ENR was incorporated into the silica-filled SBR compound at 5.0 and 10.0 phr. An investigation was carried out to examine the effect of ENR on cure characteristics and tensile properties of the silica-filled SBR compound. It was found that ENR gave enhanced cure rate to the silica-filled SBR compound. ENR also exhibited a higher torque difference, tensile modulus, and tensile strength up to 10.0 phr. The study of rubber - filler interaction proved that the addition of ENR to the silica-filled SBR system improved the rubber - filler interaction.

Photocatalytic Activity and Properties of Nanotitanium Dioxide-Filled Natural Rubber in the Presence of Coupling Agents

2015 ◽  
Vol 659 ◽  
pp. 474-478
Author(s):  
Pornsiri Toh-Ae ◽  
Banja Junhasavasdikul ◽  
Natinee Lopattananon ◽  
Kannika Sahakaro
Keyword(s):  
Photocatalytic Activity ◽  
Natural Rubber ◽  
Coupling Agent ◽  
Inorganic Filler ◽  
White Pigment ◽  
Photodegradation Efficiency ◽  
Rubber Compounds ◽  
Cure Time ◽  
The Difference ◽  
Direct Incorporation

Titanium dioxide (TiO2) is normally added into the rubber compounds as a white pigment and inorganic filler for an improvement of thermal property. TiO2 is also known to have an outstanding photocatalytic activity. This work investigates the properties of natural rubber (NR) compounds filled with 5 phr of nanoTiO2 (n-TiO2). Since the direct incorporation of n-TiO2 into NR encounters incompatibility problem, therefore two types of coupling agent (i.e. bis-(3-triethoxysilylpropyl) tetrasulfide (TESPT) and isopropyl trioleyl titanate (ITT)) are used. The coupling agent loading is varied in a range of 0-20 wt% relative to the n-TiO2. Mooney viscosities and minimum cure torque (ML) of the compounds increase with increasing coupling agent content and the ones with ITT show higher viscosity than the mixes with TESPT. The use of TESPT leads to shorter optimum cure time and higher torque difference compared to the use of ITT. The addition of n-TiO2 results in the improved modulus, reinforcing index and tensile strength compared to the unfilled vulcanizate. The presence of both TESPT and ITT significantly reduces a photodegradation efficiency. The difference in the properties and photocatalytic activity of n-TiO2 filled NR having TESPT and ITT as coupling agent indicates their possible different level of dispersion and interactions at the interphases.

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