Study of Cure Synergism of the Thiocarbamylsulfenamide-Dibenzothiazyl Disulfide Accelerator System in the Vulcanization of Natural Rubber

1983 ◽  
Vol 56 (4) ◽  
pp. 827-837 ◽  
Author(s):  
D. Pal ◽  
B. Adhikari ◽  
D. K. Basu ◽  
A. K. Chaudhuri
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Physical Properties ◽  
Structural Characterization ◽  
Crosslink Density ◽  
Synergistic Activity ◽  
Elongation At Break ◽  
Equimolar Concentration ◽  
Accelerator System

Abstract N-cyclopentamethylenethiocarbamyl-N′-cyclopentamethylenesulfenamide (CPTCS) and dibenzothiazyldisulfide (MBTS), as binary accelerators in a mixture have been found to provide significant mutual enhanced activity with regard to modulus, tensile strength, hardness, and elongation at break in the vulcanization of NR gum stocks. The synergistic activity of the CPTCS-MBTS system is very much dependent upon the accelerator ratios, concentration of sulfur and accelerator, as well as the temperature of vulcanization. Investigations carried out with the Monsanto rheometer also corroborate the above results. It is suggested that the synergism arises out of the interaction between CPTCS and MBTS which produces intermediate accelerators. N,N-Diethylthiocarbamyl-N′-cyclohexylsulfenamide (DETCS) in conjunction with MBTS, produces similar results in the vulcanization of NR. Structural characterization of the vulcanizates obtained at 140 and 160°C reveals that predominantly monosulfidic linkages are obtained with CPTCS or DETCS and MBTS combinations. The intermediate combinations, at near equimolar concentration of the two accelerators, exhibit maximum crosslink density. An attempt has been made to correlate physical properties with crosslink density as well as various types of crosslinks.

Preparation and Characterization of Rice Husk Powder Incorporated Natural Rubber Latex Foam

2012 ◽  
Vol 626 ◽  
pp. 523-529 ◽  
Author(s):  
Shamala Ramasamy ◽  
Hanafi Ismail ◽  
Yamuna Munusamy
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Rice Husk ◽  
Structural Characterization ◽  
Natural Rubber Latex ◽  
Filler Loading ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Rice Milling

Rice husk powder (RHP) is an abundant agricultural by product that is produced in bulk quantity as part of rice milling. This research is carried out to incorporate RHP with natural rubber latex (NRL) compound. Different loading of RHP is added to NRL compound and is foamed to make natural rubber latex foam (NRLF) using a well known technique called the Dunlop method. The tensile properties of modified NRLF is studied and compared with the controlled NRLF which has zero RHP loading. The morphology and micro structural characterization has been performed by Tabletop microscopy (TM1000). The tensile strength decreases at 2.5 pphr but increases again as the filler loading increases. Elongation at break decreases whereas modulus at 100% elongation (M 100) and hardness increases as the filler loading increases.

scholarly journals The effects of alkanolamide addition on cure characteristics, swelling behaviour and tensile properties of silica-filled natural rubber (NR) / chloroprene rubber (CR) blends

2018 ◽  
Vol 34 ◽  
pp. 01030 ◽  
Author(s):  
Indra Surya ◽  
Syahrul Fauzi Siregar ◽  
Hanafi Ismail
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Crosslink Density ◽  
Tensile Modulus ◽  
Palm Stearin ◽  
Swelling Behaviour ◽  
Elongation At Break ◽  
Cure Characteristics ◽  
Chloroprene Rubber

Effects of alkanolamide (ALK) addition on cure characteristics, swelling behaviour and tensile properties of silica-filled natural rubber (NR)/chloroprene rubber (CR) blends were investigated. The ALK was synthesized from Refined Bleached Deodorized Palm Stearin (RBDPS) and diethanolamine, and incorporated into the silica-filled NR/CR blends as a non-toxic rubber additive. The ALK loadings were 0.0, 1.0, 3.0, 5.0 and 7.0 phr. It was found that the ALK exhibited shorter scorch and cure times and higher elongation at break of the silica-filled NR/CR blends. The ALK also exhibited higher torque differences, tensile modulus and tensile strength at a 1.0 phr of ALK loading and then decreased with further increases in the ALK loading. The swelling measurement proved that the 1.0 phr loading of ALK caused the highest degree in crosslink density of the silica-filled NR/CR blends.

Effect of Peroxide Content on Morphology and Properties of Thermoplastic Vulcanizates Based on PP and NR

2011 ◽  
Vol 284-286 ◽  
pp. 1854-1860 ◽  
Author(s):  
Rui Wang ◽  
Zheng Peng ◽  
Peng Peng Fan
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Shear Stress ◽  
Elastic Modulus ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Elongation At Break ◽  
Peroxide Content ◽  
Thermoplastic Vulcanizates ◽  
Rubber Phase

Thermoplastic vulcanizates (TPVs) of natural rubber (NR) and polypropylene (PP) (60:40) containing various dosages (0.5-5.5phr) of peroxide were prepared using a Haake Rheocord. The effects of peroxide content on the crosslink density, thermal behaviors, morphology, mechanical and rheological properties of NR/PP TPVs were studied. The crosslink density of TPVs increased with increasing of peroxide content. However, the tensile strength, tear strength and elongation at break obtained the maximum values when 2.5phr peroxide was added, which was ascribed to the presence of smallest particle size of crosslinked rubber phase at this peroxide content. It was proposed that the effect of DCP, which not only initiated crosslink reaction in NR phase, but also degraded the polypropylene molecules, played an important role in determined the morphology and properties of TPVs. The viscosity of TPVs decreased with shear stress, indicating pseudoplastic nature of the TPV samples. The elastic modulus of the samples gradually increases with the increase in DCP content.

Influence of Modified Cassava Peel Waste (CPW) Loading on Tensile Properties of Natural Rubber Latex (NRL) Products

2015 ◽  
Vol 1119 ◽  
pp. 342-346
Author(s):  
Hamidah Harahap ◽  
Kelvin Hadinatan ◽  
Adrian Hartanto ◽  
Elmer Surya ◽  
Indra Surya ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Natural Rubber Latex ◽  
Tensile Modulus ◽  
Rubber Matrix ◽  
Tensile Fracture ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Cassava Peel

Cassava peel is one of agricultural waste that abundantly found in environment. One approach to manage this waste is to apply it as filler in natural rubber latex. In this work, the cassava peel waste (CPW) was powdered and dispersed in alkanolamide-water dispersion system to modify its surface. The amount of fillers used was 0, 5, 10, 15, 20 and 25 phr (part per hundred rubber) and loaded in natural rubber latex (NRL) formulation system. The products then were formed by dipping method after the NRL formulation was pre-vulcanized at 70°C. The observed parameter includes crosslink density, tensile strength, tensile modulus and elongation at break. Scanning Electron Microscope (SEM) was used to study the morphology of tensile fracture in NRL film. The results show that 10 phr loading of modified fillers increases the crosslink density, tensile strength, and tensile modulus but decreases the elongation at break. SEM study also reveals that higher filler loading above 10 phr will create the agglomeration in rubber matrix.

Physical Properties of Rice Husk Fiber/Natural Rubber Composites

2011 ◽  
Vol 410 ◽  
pp. 90-93 ◽  
Author(s):  
Ladawan Srisuwan ◽  
Kasama Jarukumjorn ◽  
Nitinat Suppakarn
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Rice Husk ◽  
Crosslink Density ◽  
Morphological Properties ◽  
Rubber Composites ◽  
Elongation At Break ◽  
Natural Rubber Composites ◽  
Reinforcing Filler

In this study, rice husk fiber (RHF) was used as a reinforcing filler for natural rubber (NR). NR composites were prepared at various RHF contents, i.e., 10, 20, 30, 40 and 50 phr. Sulfur conventional vulcanization was used. Effect of RHF content on cure characteristics, mechanical properties and morphological properties of NR composites were investigated. The results showed that scorch and cure times of RHF/NR composites were not affected by increasing RHF content. Crosslink density, tensile strength, elongation at break and tear strength of NR composites slightly decreased with increasing RHF content whereas M100 and M300 of the composites slightly increased with increasing RHF content.

Structural Characterization of Vulcan-Izates. XII. Efficient Vulcanization Using a Sulfenamide-Thiuram Disulfide Accelerator System

1972 ◽  
Vol 45 (5) ◽  
pp. 1366-1371 ◽  
Author(s):  
D. S. Campbell
Keyword(s):  
Natural Rubber ◽  
Structural Characterization ◽  
High Ratio ◽  
Mixed System ◽  
Tetramethylthiuram Disulfide ◽  
Sulfur Vulcanization ◽  
Cure Time ◽  
Accelerator System ◽  
Cyclic Sulfide

Abstract Vulcanizates obtained from the sulfur vulcanization of natural rubber using a combination of the accelerators N-cyclohexyl-2-benzothiazole sulfenamide (CBS) and tetramethylthiuram disulfide (TMTD) have been analyzed in terms of the numbers of poly-, di-, and monosulfide crosslinks, network-bound accelerator residues, and cyclic sulfide chain modifications as a function of cure time. The vulcanization system produced mainly monosulfide crosslinks at optimum cure, although there were differences in detail between this mixed system and a previously reported efficient sulfur vulcanization (EV) system using a high ratio of CBS to sulfur.

scholarly journals PENGARUH PENAMBAHAN ALKANOLAMIDA TERHADAP SIFAT-SIFAT UJI TARIK VULKANISAT KARET ALAM BERPENGISI KAOLIN

2013 ◽  
Vol 2 (4) ◽  
pp. 1-5
Author(s):  
Yudha Widyanata ◽  
Indah M.S. Sitorus ◽  
Indra Surya
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Crosslink Density ◽  
Density Measurement ◽  
Tensile Modulus ◽  
Rubber Compound ◽  
Elongation At Break ◽  
Break Up

By using a semi-efficient vulcanization system, Alkanolamide (ALK) was incorporated into kaolin-filled natural rubber compound at 1.0; 3.0; 5.0 and 7.0 parts per hundred rubber (phr). An investigation was carried out to examine the effect of ALK on tensile properties of the kaolin filled-natural rubber compound. It was found that ALK exhibited higher tensile modulus, tensile strength, and elongation at break up to 5.0 phr of ALK loading and then decreased with further increasing of ALK loading. Crosslink density measurement proved that 5.0 phr loading of ALK in the kaolin-filled natural rubber system exhibited greatest tensile properties due to its highest crosslink density formation.

scholarly journals Loading Silica for Supporting Carbon Black Filler to Prevent Degradation Natural Rubber Caused DME

2021 ◽  
Vol 333 ◽  
pp. 13001
Author(s):  
Asep Handaya Saputra ◽  
Tuti Indah Sari ◽  
Dadi R. Maspanger ◽  
Setijo Bismo
Keyword(s):  
Tensile Strength ◽  
Carbon Black ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Filler Loading ◽  
High Permeability ◽  
Elongation At Break ◽  
Percentage Decrease ◽  
Silica Filler ◽  
Before And After

DME (Dimethyl Ether) is the future environmental friendly fuel. Some parts of equipment for transporting the DME are using rubber as a hoses or seals. This research is about the using of natural rubber for those applications. The influential part in the manufacture of natural rubber products are fillers. The use of filler depends on what the product will be made. DME nature have high permeability and easy to absorb into a rubber and plastic. In such of that, the rubber or plastic could be damaged and not durable. In order to determine the type of degradation, the number of samples were immersed in liquid DME. The ratio of the loading of carbon black/silica filler in natural rubber was varied. DME causes two types of degradation, namely absorption and extraction. The addition of filler composition can reduce the absorption and extraction, which can cause a reduction in the percentage decrease in the value of the change in mass and a decrease in tensile strength. On the other hand, the addition of filler composition will increase the changes of hardness. The higher filler loading, will increase the crosslink density and lower scorch time. The presence of silica further is to enhance the crosslink density as well as to lower scorch time. Therefore, the presence of silica affect on the decreasing of the swelling level and shrinking. In general, the presence of silica filler in the mixture will be slightly lowering the tensile strength, but not affecting the elongation at break. The presence of silica before and after soaking with DME will increase hardness.

Pengaruh penambahan natural rubber (NR), epoxidation natural rubber (ENR-46) dan chlorprene rubber (CR) pada sifat kompon termoplastik

2020 ◽  
Vol 26 (2) ◽  
pp. 62-69
Author(s):  
Farida Ali ◽  
Tuti I. Sari ◽  
Andi A. Siahaan ◽  
Al-Kautsar D. Arya ◽  
Tri Susanto
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Vinyl Chloride ◽  
Butadiene Rubber ◽  
Elongation At Break ◽  
Nitrile Butadiene Rubber ◽  
Poly Vinyl Chloride

Penelitian ini untuk mengetahui pengaruh penambahan Natural Rubber (NR) dan Epoxidation Natural Rubber (ENR-46) dengan kompatibiliser Chlorprene Rubber (CR) pada aplikasi kompon termoplastik Poly Vinyl Chloride (PVC) dan Nitrile Butadiene Rubber (NBR), variabel penelitian meliputi ENR-46/PVC/NBR/CR, NR/PVC/NBR/CR dan CR-NR/PVC/NBR, CR-ENR-46/PVC/NBR. Parameter pengujian sifat fisik-mekanik : Hardness (Shore A), Tensile Strength (Mpa), Elongation at Break (%) dan ketahanan terhadap pelarut minyak (n-Pentane, Toluene, Hexane dan Pertalite). Hasil penelitian didapatkan untuk sifat fisik-mekanik, semakin banyak penambahan NR Kekerasan kompon termoplastik akan menurun, Tensile Strength dan Elongation at Break kompon akan meningkat begitu juga dengan CR-NR. Tetapi berbanding terbalik hasilnya untuk ENR-46 dan CR-ENR-46. Pengujian Ketahanan terhadap pelarut minyak semakin banyak penambahan ENR-46 Ketahanan kompon termoplastik terhadap pelarut akan meningkat, hasil yang sama juga pada CR-ENR-46. Tetapi berbanding terbalik hasilnya dengan penambahan NR dan CR-NR pada kompon termoplastik.

Preparation and Characterization of β-glucosidase Films for Stabilization and Handling in Dry Configurations

2020 ◽  
Vol 21 (8) ◽  
pp. 741-747
Author(s):  
Liguang Zhang ◽  
Yanan Shen ◽  
Wenjing Lu ◽  
Lengqiu Guo ◽  
Min Xiang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Protein Function ◽  
Protein Stabilization ◽  
Functional Protein ◽  
Elongation At Break ◽  
Gelatin Films ◽  
The Stability ◽  
And Function ◽  
General Method

Background: Although the stability of proteins is of significance to maintain protein function for therapeutical applications, this remains a challenge. Herein, a general method of preserving protein stability and function was developed using gelatin films. Method: Enzymes immobilized onto films composed of gelatin and Ethylene Glycol (EG) were developed to study their ability to stabilize proteins. As a model functional protein, β-glucosidase was selected. The tensile properties, microstructure, and crystallization behavior of the gelatin films were assessed. Result: Our results indicated that film configurations can preserve the activity of β-glucosidase under rigorous conditions (75% relative humidity and 37°C for 47 days). In both control films and films containing 1.8 % β-glucosidase, tensile strength increased with increased EG content, whilst the elongation at break increased initially, then decreased over time. The presence of β-glucosidase had a negligible influence on tensile strength and elongation at break. Scanning electron-microscopy (SEM) revealed that with increasing EG content or decreasing enzyme concentrations, a denser microstructure was observed. Conclusion: In conclusion, the dry film is a promising candidate to maintain protein stabilization and handling. The configuration is convenient and cheap, and thus applicable to protein storage and transportation processes in the future.

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