Influence of bound polymer on cure characteristics of natural rubber compounds reinforced with different types of carbon blacks

2005 ◽  
Vol 98 (5) ◽  
pp. 2282-2289 ◽  
Author(s):  
Sung-Seen Choi ◽  
Ki-Jun Hwang ◽  
Beom-Tae Kim
Keyword(s):  
Natural Rubber ◽  
Carbon Blacks ◽  
Cure Characteristics ◽  
Rubber Compounds ◽  
Different Types

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.

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.

scholarly journals Physico-mechanical properties of rubber seed shell carbon: Filled natural rubber compounds

2010 ◽  
Vol 16 (2) ◽  
pp. 149-156 ◽  
Author(s):  
L.O. Ekebafe ◽  
J.E. Imanah ◽  
F.E. Okieimen
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Bulk Density ◽  
Surface Area ◽  
Heating Temperature ◽  
Filler Loading ◽  
Loss On Ignition ◽  
Rubber Seed ◽  
Cure Characteristics ◽  
Rubber Compounds

Samples of rubber seed shells were carbonized at varying temperatures (100, 200, 300, 400, 500, 600, 700, 800?C) for three hours each and sieved through 150?m screen. The portion of the rubber seed shell carbon that passed through the screen was characterized in terms of loss on ignition, surface area, moisture content, pH, bulk density, and metal content and used in compounding natural rubber. The characterization shows that the pH, conductivity, loss on ignition and the surface area increases as the heating temperature increases, unlike the bulk density which decreases. The compound mixes were cured using efficient vulcanization system. Cure characteristics and physico-mechanical properties of the vulcanisates were measured as a function of filler loading along with that of N330 carbon-black filled natural rubber vulcanisate. The results of the cure characteristics showed that the cure times, scorch times and the torque gradually increased, with increasing filler content for rubber seed shell carbon-filled natural rubber, with filler obtained at carbonizing temperature of 600?C tending to show optimum cure indices. The physico-mechanical properties of the vulcanisates increase with filler loading. The reinforcing potential of the carbonized rubber seed shell carbon was found to increase markedly for the filler obtained at the temperature range 500-600?C and then decrease with further increase in temperature.

scholarly journals CURE CHARACTERISTICS AND CROSSLINK DENSITY OF NATURAL RUBBER/STYRENE BUTADIENE RUBBER BLENDS

2015 ◽  
Vol 3 (4) ◽  
pp. 1-5
Author(s):  
Indra Surya ◽  
Syahrul Fauzi Siregar
Keyword(s):  
Natural Rubber ◽  
Crosslink Density ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Blend Ratio ◽  
Rubber Blends ◽  
Cure Characteristics ◽  
Rubber Compounds ◽  
Cure Time ◽  
Styrene Butadiene

By using a semi-efficient vulcanization system, the cure characteristics and crosslink density of natural rubber/styrene butadiene rubber (NR/SBR) blends were studied with a blend ratio from 0 to 100% rubber. The scorch time, optimum cure time, and torque difference value of the blended rubber compounds were determined by using the Moving-Die Rheometer (MDR 2000). The crosslink density was determined by the Flory—Rehner approach. Results indicate that the scorch and cure times, ts2 and t90, of the NR/SBR blends increased with increasing the SBR content. Whilst, the maximum values of torque difference and crosslink density were performed by the NR/SBR blend with a blend ratio of 75/25.

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