Study on sulfur vulcanized natural rubber formulated with nitrosamine safe diisopropyl xanthogen polysulfide/tertiary butyl benzothiazole sulphenamide binary accelerator system

2020 ◽  
pp. 147776062097749
Author(s):  
IHK Samarasinghe ◽  
S Walpalage ◽  
DG Edirisinghe ◽  
SM Egodage
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Strength Properties ◽  
Nitroso Compounds ◽  
Tertiary Butyl ◽  
Study Behavior ◽  
Cure Characteristics ◽  
Sulfur Vulcanization ◽  
Cure Time ◽  
Accelerator System

An outstanding interest on elimination of nitrosamine generation in traditional sulfur vulcanization systems has led to introduce nitrosamine safe accelerator/s to produce safe natural rubber (NR) vulcanizates. It is an effective way to prevent formation of carcinogenic N-nitroso compounds during manufacture of rubber products. In the present study, behavior of nitrosamine safe binary accelerator system consisting of diisopropyl xanthogen polysulfide (DIXP) with commonly used non-regulated accelerator N-tert-butyl-2-benzothiazole sulfenamide (TBBS) was investigated in efficient sulfur vulcanization of NR. Cure characteristics, physico-mechanical properties and crosslink density of vulcanizates prepared with different combinations of the accelerator system were evaluated and compared with those of individual accelerators. The study reveals that moduli and strength properties of the vulcanizate prepared with DIXP accelerator are inferior to those of the vulcanizate prepared with TBBS accelerator. Nevertheless, optimum cure time of the DIXP compounds is lower in comparison to TBBS compounds. Moreover, progressive replacement of DIXP with TBBS in the accelerator system showed a synergistic effect in regard to cure characteristics and physico-mechanical properties.

Influence of Filler Types on Mechanical Properties and Cure Characteristics of Natural Rubber Composites

2011 ◽  
Vol 264-265 ◽  
pp. 646-651 ◽  
Author(s):  
Wittawat Wongsorat ◽  
Nitinat Suppakarn ◽  
Kasama Jarukumjorn
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Carbon Black ◽  
Natural Rubber ◽  
Sisal Fiber ◽  
Maximum Torque ◽  
Cure Characteristics ◽  
Roll Mill ◽  
Fiber Treatment ◽  
Cure Time

Natural rubber (NR) was reinforced with three types of filler: carbon black, calcium carbonate, and sisal fiber. NR composites were prepared on a two-roll mill. Filler content was 20 phr. Mechanical properties and cure characteristics of NR composites were studied. All NR composites had higher maximum torque than NR. NR filled with carbon black showed the highest maximum torque. However, scorch time and cure time of the NR composites were not much affected by filler types. In addition, influence of fiber treatment (alkalization) on mechanical properties and cure characteristics of sisal fiber-NR composites was investigated. Alkali treated sisal fiber-NR composite exhibited higher tensile properties and hardness than untreated sisal fiber- NR composite due to improved adhesion between the fiber and NR matrix. Moreover, alkali treated sisal fiber-NR composite had superior specific modulus and strength than NR composites filled with carbon black and calcium carbonate.

EFFECT OF BENZOTHIAZOLOYLTHIAZOLES AS SECONDARY ACCELERATORS IN THE SULFUR VULCANIZATION OF NATURAL RUBBER

2011 ◽  
Vol 84 (1) ◽  
pp. 88-100 ◽  
Author(s):  
R. Reshmy ◽  
R. Nirmal ◽  
S. Prasanthkumar ◽  
K. Kurien Thomas ◽  
Molice Thomas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Chemical Method ◽  
Binary Systems ◽  
Minimal Amount ◽  
Tetramethylthiuram Disulfide ◽  
Solvent Free Conditions ◽  
Sulfur Vulcanization ◽  
Cure Time

Abstract The vulcanization of natural rubber and a blend of natural rubber and reclaimed rubber by using binary accelerator systems containing a novel series of benzothiazoloylthiazole as secondary accelerator (SA) has been studied. These secondary accelerators were synthesized by a green chemical method under solvent-free conditions, by the irradiation of microwaves (180 W). The synergistic effect of the SA with N-Cyclohexyl-2-benzothiazolsulfenamide as primary accelerator was studied at 150 °C. These binary systems were effective in reducing the cure time and improving the rheometric and mechanical properties. These SAs were found to be effective in reducing the cure time with a minimal amount of 0.5 phr, but commercially available SAs such as thioureas and tetramethylthiuram disulfide were reported to show reduction in cure time only by increasing the amount of SA. Mechanical properties such as hardness, abrasion loss, tensile strength, percentage strain at break, and modulus at different elongations 100, 200, and 300% were evaluated and found to be immensely improved. The improved mechanical properties were also shown to be at par with crosslink densities (1/2Mc) of different mixes.

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.

Effect of Oleic Acid on Properties of Natural Rubber Filled Bacterial Cellulose

2017 ◽  
Vol 744 ◽  
pp. 295-299
Author(s):  
Saowaluk Boonyod ◽  
Chaiwute Vudjung
Keyword(s):  
Mechanical Properties ◽  
Oleic Acid ◽  
Natural Rubber ◽  
Bacterial Cellulose ◽  
Elongation At Break ◽  
Tear Strength ◽  
Cure Characteristics ◽  
Roll Mill ◽  
Cure Time ◽  
Mooney Viscosity

Natural rubber (NR) containing the nata de coco fiber or Bacterial cellulose (BC) was prepared by co-coagulation of BC and concentrated NR latex with CaCl2 and compounded by two roll mill. The effect of oleic acid (OA) containing in NR filled BC (NR/BC) was the important factor in this study. BC was varied from 0–25 parts per hundred parts of rubber (phr), and the Mooney viscosity, cure characteristics and mechanical properties of NR/BC with and without OA as compatiblizer was evaluated. It was found that tear strength and elongation at break of NR/BC containing OA improved. The addition of OA into NR/BC affect vulcanization properties of NR/BC masterbatch that retard the cure time of their compound. Of all BC contents investigated, the vulcanized NR/BC at 10-20 phr of BC with OA shows the optimum tear strength and the morphology of the vulcanized NR/BC is improved by the addition of OA.

Mechanical Properties, Morphological Properties, and Cure Characteristics of Sisal Fiber/Natural Rubber Composites: Effects of Fiber and Compatibilizer Content

2010 ◽  
Vol 123-125 ◽  
pp. 1171-1174 ◽  
Author(s):  
Wittawat Wongsorat ◽  
Nitinat Suppakarn ◽  
Kasama Jarukumjorn
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Positive Impact ◽  
Morphological Properties ◽  
Sisal Fiber ◽  
Maximum Torque ◽  
Cure Characteristics ◽  
Roll Mill ◽  
Cure Time

Sisal fiber/natural rubber (NR) composites were prepared by the incorporation of sisal fiber into NR at various content (10, 20, 30 phr) using a two-roll mill. Natural rubber grafted with maleic anhydride (NR-g-MA) prepared in house was used to improve interfacial adhesion between sisal fiber and NR matrix. NR-g-MA contents were varied. Mechanical properties, morphologies, and cure characteristics of the composites were studied. Maximum torque, modulus at 100% strain (M100), modulus at 300% strain (M300), and hardness of the composites increased with increasing fiber content while scorch time, cure time, tensile strength, and elongation at break decreased. The addition of NR-g-MA into the composites gave a positive impact on M100, M300, tensile strength, and hardness. Moreover, increasing NR-g-MA content resulted in increased scorch time, cure time, maximum torque, M100, M300, tensile strength, and hardness of the composites. SEM micrographs of the composites revealed that the addition of NR-g-MA into the composites improved the interfacial interaction between sisal fiber and NR matrix. In addition, the compatibilized NR composites exhibited higher specific tensile strength and modulus than the carbon black/NR composites.

Cure Characteristics and Mechanical Properties of ZnO Nanoparticles as Activator in Unfilled Natural Rubber

2014 ◽  
Vol 1044-1045 ◽  
pp. 23-26 ◽  
Author(s):  
Rudeerat Suntako
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Zno Nanoparticles ◽  
Permanent Deformation ◽  
Zinc Nitrate ◽  
Hexagonal Structure ◽  
Precipitation Method ◽  
Cure Characteristics ◽  
Nitrate Tetrahydrate ◽  
Cure Time

In this work, the effect of ZnO nanoparticles as activator is studied in unfilled natural rubber and compared with conventional ZnO on cure characteristics and mechanical properties. ZnO nanoparticles are synthesized by precipitation method using zinc nitrate tetrahydrate and sodium hydroxide as precursor. Particle size of ZnO nanoparticles can be controlled by polymeric additive. It is found that the average primary size of synthesized ZnO nanoparticles around 28.71 nm and the specific surface area around 31.45 m2/g. The crystalline structure exhibits hexagonal structure with wurtzite. The rheological properties of unfilled natural rubber show that the maximum torque (MH) and the optimum cure time (t90) increase with increasing synthesized ZnO nanoparticles loading. The minimum torque (ML) of unfilled natural rubber which uses synthesized ZnO nanoparticles loading higher than conventional ZnO. Compression set and tension set are the permanent deformation also investigated. It is found that deformation reduces when increase synthesized ZnO nanoparticles loading. The mechanical properties such as hardness, tensile strength, 100% and 300% modulus, tear strength, elongation at break are improved, without detrimental effect on properties. For unfilled natural rubber, synthesized ZnO nanoparticles can be reduced successfully from 5 to 2 phr and stearic acid 1 to 0.3 phr, respectively.

Effects of Surfactant Content and Clay Content on Properties of NR Nanocomposites

2010 ◽  
Vol 123-125 ◽  
pp. 55-58 ◽  
Author(s):  
Chalermpan Keawkumay ◽  
Kasama Jarukumjorn ◽  
Nitinat Suppakarn
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Clay Content ◽  
Exchange Capacity ◽  
Cure Characteristics ◽  
Roll Mill ◽  
Cure Time

Montmorillonite (MMT) was modified by octadecylamine (ODA) surfactant. The surfactant contents were varied, i.e. 0.5, 1.0 and 2.0 times the cation exchange capacity (CEC) of the MMT. XRD and FTIR spectra of the organoclay revealed that ODA molecules intercalated into MMT layers. The MMT-ODA was melt-mixed with natural rubber (NR) using a two roll mill. Effects of surfactant content and organoclay content on cure characteristics, mechanical properties, and morphologies of NR nanocomposites were investigated. Morphologies of the NR nanocomposites, with increasing surfactant content, revealed the exfoliated structure and the good dispersion of the organoclay in the NR matrix. These caused the enhancement of mechanical properties of the NR nanocomposites. With increasing the MMT-ODA2 content up to 5 phr, scorch time and cure time of the NR nanocomposites decreased while their tensile strength increased.

scholarly journals Effect of Lanthanum Cerium Cysteine on Cure Characteristics, Mechanical Properties, and Thermooxidative Aging for Natural Rubber

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Wentao Zhang ◽  
Zhaogang Liu ◽  
Shuai Li ◽  
Wei Hao ◽  
Yanhong Hu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Zinc Oxide ◽  
Natural Rubber ◽  
Rare Earths ◽  
Decomposition Reaction ◽  
Molecular Formula ◽  
Multifunctional Additive ◽  
Cure Characteristics ◽  
Aging Properties ◽  
Sulfur Vulcanization

In this work, a novel additive lanthanum cerium cysteine (LC-Cys), with the molecular formula La0.35Ce0.65(Cys)3Cl3·3H2O, was successfully synthesized through complex decomposition reaction of L-Cysteine and chlorinated rare earths. The effects of additive LC-Cys on cure characteristics, mechanical properties, and thermooxidative aging were investigated. LC-Cys as a multifunctional additive was applied to increase the curing rate and reduce the content of zinc oxide in the presence of the sulfur vulcanization system. It was found that the vulcanizates filled with (5ZnO/2LC-Cys) exhibited the highest modulus, which indirectly indicated the high crosslink and stiffness of the vulcanizates. Moreover, the vulcanizates with LC-Cys showed excellent mechanical properties and resistance to thermooxidative aging. Compared to NR composites filled with normal ZnO, LC-Cys even enhanced the mechanical strength and thermooxidative aging properties with 40% lower ZnO addition.

Effect of Nanosilica Fillers on the Cure Characteristics and Mechanical Properties of Natural Rubber Composites

2012 ◽  
Vol 626 ◽  
pp. 818-822 ◽  
Author(s):  
Makara Lay ◽  
A. Rashid Azura ◽  
Nadras Othman ◽  
Yasuyuki Tezuka ◽  
Chhorda Pen
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Sem Analysis ◽  
The Other ◽  
Tensile Fracture ◽  
Rubber Composites ◽  
Cure Characteristics ◽  
Ftir Characterization ◽  
Natural Rubber Composites ◽  
Cure Time

In recent years, polymer/nanofiller composites have received intense attention and become a core focus of nanoscience and nanotechnology. In polymer-nanoscale filler composites research, the primary goal is to enhance the strength and toughness of polymeric components using molecular or nanoscale reinforcement. In this study, nanosilica was used as filler with various loading from 1-5 phr to enhance mechanical properties and cure characteristics of natural rubber composites. 3 phr of nanosilica filler loadings showed highest tensile strength and shortest cure time compared to the other filler loadings. Tear strength was improved with increasing filler loadings. The effect of nanosilica loading has been analyzed using FTIR characterization and the tensile fracture was investigated by SEM analysis.

Elastomer nanocomposites based on NBR/BR/nanoclay: morphology and mechanical properties

2013 ◽  
Vol 33 (2) ◽  
pp. 133-139 ◽  
Author(s):  
Shohreh Tolooei ◽  
Ghasem Naderi ◽  
Shirin Shokoohi ◽  
Sedigheh Soltani
Keyword(s):  
Mechanical Properties ◽  
Polymer Chains ◽  
Butadiene Rubber ◽  
Cure Characteristics ◽  
Fluid Uptake ◽  
Roll Mill ◽  
Dispersion State ◽  
Cure Time ◽  
Diffraction Patterns ◽  
Nanoclay Content

Abstract Ternary elastomer nanocomposites based on acrylonitrile butadiene rubber (NBR), polybutadiene rubber (BR) and two types of nanoclay (Cloisite 15A and Cloisite 30B) were prepared using a laboratory scale two-roll mill. The effects of nanoclay composition on the cure characteristics, mechanical properties and morphology of NBR/BR (50/50) nanocomposite samples containing 3, 5, 7 and 10 wt% nanoclay were investigated. According to the cure characteristics both types of nanoclay caused a reduction in the scorch time and optimum cure time of the nanocomposite compound. X-ray diffraction patterns of all samples suggested the intercalation of polymer chains into the silicate layers. This was confirmed by transmission electron microscopy (TEM) micrographs. Dynamic mechanical thermal analysis (DMTA) was utilized to study the dispersion state of nanoclay within the elastomer blend matrix. The results showed the development of mechanical properties with the establishment of interactions between nanoclay and polymer chains. Antiknock and brake fluid uptake were also reduced with increasing the nanoclay content.

Sign in / Sign up

Export Citation Format

Share Document