Reinforcement of Natural Rubber with Silanized Precipitated Silica Nanofiller

2005 ◽  
Vol 78 (5) ◽  
pp. 793-805 ◽  
Author(s):  
A. Ansarifar ◽  
N. Ibrahim ◽  
M. Bennett
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Zinc Oxide ◽  
Reaction Mechanism ◽  
Energy Density ◽  
Natural Rubber ◽  
Elemental Sulfur ◽  
Stored Energy ◽  
Tear Strength ◽  
Precipitated Silica

Abstract The effect of a large amount of precipitated amorphous white silica nanofiller, pre-treated with bis[3-triethoxysilylpropyl-)tetrasulfide (TESPT), on the mechanical properties of a sulfur-cured natural rubber (NR) was studied. TESPT chemically adheres silica to rubber and also prevents silica from interfering with the reaction mechanism of sulfur-cure. The silica particles were fully dispersed in the rubber, which was cured primarily by using sulfur in TESPT, or, by adding a small amount of elemental sulfur to the cure system. The cure was also optimized by incorporating sulphenamide accelerator and zinc oxide into the rubber. The hardness, tear strength, tensile strength, and stored energy density at break of the vulcanizate were substantially improved when the filler was added. Interestingly, these properties were also enhanced when the rubber was cured primarily by using sulfur in TESPT.

The Damping Properties of the Natural Rubber Filled with ZnO

2014 ◽  
Vol 912-914 ◽  
pp. 390-394 ◽  
Author(s):  
Yan Fang Zhao ◽  
Dan Liu ◽  
Shuang Quan Liao ◽  
Xiao Xue Liao ◽  
Sheng Bo Lin
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Zinc Oxide ◽  
Natural Rubber ◽  
Damping Properties ◽  
Tear Strength ◽  
Thermal Stability Of

The research on the mechanical properties and thermal stability of the natural rubber filled with different dosage of Zinc oxide (ZnO). The results showed that with the increase of the content of the ZnO, the tensile strength first increased, then decreased the, but the tear strength showed a trend of increase,the thermal stability had improved; When the amount of ZnO added was 9, damping performance was better.

EFFECT OF ZINC DITHIOCARBAMATES AND THIAZOLE-BASED ACCELERATORS ON THE VULCANIZATION OF NATURAL RUBBER

2012 ◽  
Vol 85 (1) ◽  
pp. 120-131 ◽  
Author(s):  
Md. Najib Alam ◽  
Swapan Kumar Mandal ◽  
Subhas Chandra Debnath
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Reaction Mechanism ◽  
Natural Rubber ◽  
High Performance ◽  
Binary Systems ◽  
Synergistic Activity ◽  
Tetramethylthiuram Disulfide

Abstract Several zinc dithiocarbamates (ZDCs) as accelerator derived from safe amine has been exclusively studied in the presence of thiazole-based accelerators to introduce safe dithiocarbamate in the vulcanization of natural rubber. Comparison has been made between conventional unsafe zinc dimethyldithiocarbamate (ZDMC) with safe novel ZDC combined with thizole-based accelerators in the light of mechanical properties. The study reveals that thiuram disulfide and 2-mercaptobenzothiazole (MBT) are always formed from the reaction either between ZDC and dibenzothiazyledisulfide (MBTS) or between ZDC and N-cyclohexyl-2-benzothiazole sulfenamide (CBS). It has been conclusively proved that MBT generated from MBTS or CBS reacts with ZDC and produces tetramethylthiuram disulfide. The observed synergistic activity has been discussed based on the cure and physical data and explained through the results based on high-performance liquid chromatography and a reaction mechanism. Synergistic activity is observed in all binary systems studied. The highest tensile strength is observed in the zinc (N-benzyl piperazino) dithiocarbamate-accelerated system at 3:6 mM ratios. In respect of tensile strength and modulus value, unsafe ZDMC can be successfully replaced by safe ZDCs in combination with thiazole group containing accelerator.

Mechanochemical Devulcanization of Vulcanized Gum Natural Rubber

2005 ◽  
Vol 21 (3) ◽  
pp. 183-199
Author(s):  
G.K. Jana ◽  
C.K. Das
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Three Dimensional ◽  
Elongation At Break ◽  
Tear Strength ◽  
Vulcanized Rubber ◽  
Dimensional Network ◽  
Polymeric Chains ◽  
Cure Time

De-vulcanization of vulcanized elastomers represents a great challenge because of their three-dimensional network structure. Sulfur-cured gum natural rubbers containing three different sulfur/accelerator ratios were de-vulcanized by thio-acids. The process was carried out at 90 °C for 10 minutes in an open two-roll cracker-cum-mixing mill. Two concentrations of de-vulcanizing agent were tried in order to study the cleavage of the sulfidic bonds. The mechanical properties of the re-vulcanized rubber (like tensile strength, modulus, tear strength and elongation at break) were improved with increasing concentrations of de-vulcanizing agent, because the crosslink density increased. A decrease in scorch time and in optimum cure time and an increase in the state of cure were observed when vulcanized rubber was treated with high amounts of de-vulcanizing agent. The temperature of onset of degradation was also increased with increasing concentration of thio-acid. DMA analysis revealed that the storage modulus increased on re-vulcanization. From IR spectroscopy it was observed that oxidation of the main polymeric chains did not occur at the time of high temperature milling. Over 80% retention of the original mechanical properties (like tensile strength, modulus, tear strength and elongation at break) of the vulcanized natural rubber was achieved by this mechanochemical process.

Influences of Particle Sizes on Properties of Natural Rubber/Waste Ground Rubber Powders Blends

2013 ◽  
Vol 773 ◽  
pp. 668-672
Author(s):  
Jun Liang Liu ◽  
Ping Liu ◽  
Xiao Qiang Tang ◽  
Dong Zeng ◽  
Xing Kai Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Chemical Activation ◽  
Cross Linking ◽  
Particle Sizes ◽  
Elongation At Break ◽  
Tear Strength ◽  
Rubber Waste ◽  
Ground Rubber

In this paper, the blends of natural rubber with waste ground rubber powders have been prepared by mechano-chemical activation method. The influences of particle sizes on both processing performances and mechanical properties have been investigated. The results indicated that: the blends with waste ground rubber powders of smaller particle sizes approached to higher surface tensile and easily mechano-chemical activation, which led to the formation of complete homogenous re-vulcanization cross-linking structure and resulted in the improvements of the whole performances of the final products. The tensile strength, the elongation at break and tear strength approached to the highest value of 20.7MPa, 530% and 33.0 kN/m as the 100mesh waste ground rubber powders were used as the starting materials.

scholarly journals Preparation and modification of natural rubber blends for water purification treatment usage

2020 ◽  
Author(s):  
Wenfa Dong ◽  
Ruogu Tang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Relative Volume ◽  
Curing Time ◽  
Water Industry ◽  
High Modulus ◽  
Elongation At Break ◽  
Tear Strength ◽  
Rubber Blends

<div>The water industry used NR was selected for blending with SBR. A series of NR/SBR vulcanizates were prepared through three different vulcanization systems, conventional vulcanization (CV), effective vulcanization (EV) and semi-effective vulcanization (SEV) respectively, basing on each formulation and optimum curing time. We examined the mechanical properties of NR/SBR vulcanizates including tensile strength, tear strength, elongation at break, modulus, Shore A hardnessand and relative volume abrasion. The results indicated that NR/SBR vulcanizates prepared in different systems differed in mechanical properties. Vulcanizates prepared via CV showed higher tensile and tear strength; vulcanizates prepared via EV had high modulus and hardness, and vulcanizates prepared via SEV performed high abrasion resistance. </div>

Effect of Oyster Shell Powder Loading on the Mechanical and Thermal Properties of Natural Rubber/Oyster Shell Composites

2017 ◽  
Vol 25 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Lefan Li ◽  
Zongqiang Zeng ◽  
Zhifen Wang ◽  
Zheng Peng ◽  
Xiaodong She ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Coupling Agent ◽  
Oyster Shell ◽  
Absorption Bands ◽  
Tear Strength ◽  
Oyster Shell Powder ◽  
Shell Powder

The oyster shell powder/natural rubber composites were successfully prepared by blending the modified oyster shell powder with natural rubber (NR). The oyster shell powder with a particle size of 209 nm were well distributed within the rubber matrix. The characteristic Fourier transform infrared spectroscopy (FTIR) absorption bands of both oyster shell powder and natural rubber were observed in the FTIR spectra of NR/oyster shell powder composites. The C-O absorption bands in carbonates of composites exhibit a shift from 1425 cm−1 to 1446 cm−1 which suggests the bonds formed among oyster shell powder, earth coupling agent and NR. The tensile strength and stress at 500% elongation increased with rising of the earth coupling agent. Composites with 1.5 parts per hundred rubber (phr) coupling agent achieved the highest mechanical properties, where an increase of 13.4% in tensile strength was found. The tensile strength and tear strength increased along with an increment of oyster shell powder. When the content of oyster shell powder attained 25–30 phr, the composites exhibited the best mechanical properties. In particular, the tensile strength and tear strength increased by 27.9% and 17.2% when compared with those of the control samples. Furthermore, the addition of the oyster shell powder leads to the improvement of thermal stability which is evidenced by an increase of 8 °C in the initial degradation temperature. The improvement of the mechanical properties and thermal stability of the composites have demonstrated that the oyster shell powder can be used as potential fillers for natural rubber.

The Effect of Organic Modificaition Method onto Montmorillonite on Mechanical Properties of Natural Rubber

2008 ◽  
Vol 55-57 ◽  
pp. 341-344 ◽  
Author(s):  
Chanchai Thongpin ◽  
N. Tangchantra ◽  
P. Kaewpetch ◽  
J. Dejkun ◽  
A. Chartsiriwattana
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Organic Molecule ◽  
Elongation At Break ◽  
Tear Strength ◽  
Cure Characteristics ◽  
Modified Montmorillonite

Montmorillonite is a type of clays that has been used to reinforce polymer including rubber. Therefore this research is aimed to modify mechanical properties of natural rubber (NR) using montmorillonite (MMT) comparing with the organic modified montmorillonite (CTAB-MMT) and organic molecule grafted MMT. The affect of MMT, CTAB-MMT and HTMS-g-CTABMMT on cure characteristics of NR were studied. It was found from the research that the increase of MMT content could prolong the scorch time whereas CTAB-MMT and HTMS-g-CTABMMT could shorten the scorch time. The cure times of the compounds in all cases were not much different. In term of mechanical properties, modulus, tensile strength and tear strength of NR/HTMS-g-CTABMMT vulcanizate were higher than those of NR/MMT and NR/CTAB-MMT vulcanizates. Meanwhile, elongation at break of the NR/ HTMS-g-CTABMMT vulcanizate decreased more than the latter cases

Reinforcement of Natural Rubber with Quartz/Sericite/Wollastonite

2011 ◽  
Vol 239-242 ◽  
pp. 2953-2957 ◽  
Author(s):  
Jun Fang Guan ◽  
Hui Qun Yang ◽  
Yan Qiang Yu ◽  
Yang Chen ◽  
Guo Bing Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Rubber Matrix ◽  
Coupling Agents ◽  
Mass Ratio ◽  
Silane Coupling Agents ◽  
Elongation At Break ◽  
Tear Strength ◽  
Parallel Arrangement

In the paper, ultrafine quartz, sericite and wollastonite modified with silane coupling agents KH-570 were incorporated into natural rubber(NR). The synergisitc effect on reinforcing NR caused by the three types of fillers was investigated under a same vulcanizing formulation and process. The mechanical properties and microstructure of the vulcanizates were conducted through mechanical testing and scanning electron microscopy(SEM). The results of mechanical properties tests showed that when one of these three fillers was loaded within NR alone, the tear strength and permanent set of NR vulcanizates filled with quartz could reach 27.61 kN m-1and 16.0%, respectively, stress at 300% elongation of NR vulcanizates filled with sericite could attain 4.69 MPa, and the tensile strength and elongation at break of NR vulcanizates filled with wollastonite could get to16.64 MPa and 951.21%, respectively. Under the condition that the filler loadings were 40 parts per hundred parts of rubber(phr), and the mass ratio of quartz, sericite, wollastonite was 1:1:3, the tensile strength and tear strength could come up to 17.33MPa and 27.54 kN m-1. The mechanical properties of NR composites filled with mixtures were found to be complemented by those three types of minerals. SEM results revealed that the fillers are well dispersed in the rubber matrix in the parallel arrangement with a densest stack, and the synergistic reinforcment effect of the fillers on NR was obvious.

Mechanical Behavior of Polystyrene-Grafted Natural Rubber/Natural Rubber Blend: Effect of Polystyrene Grafting Percentage

2017 ◽  
Vol 751 ◽  
pp. 308-313 ◽  
Author(s):  
Tarakol Hongkeab ◽  
Peerapan Dittanet
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Reaction Times ◽  
Rubber Compound ◽  
Tear Strength ◽  
Emulsion Copolymerization ◽  
Rigid Chain ◽  
Transmission Electron ◽  
Core Shell Structure

Polystyrene-grafted natural rubber (PS-GNR) at various graft levels was evaluated to improve mechanical properties of natural rubber (NR). PS-GNR was synthesized by emulsion copolymerization at 60°C at different reaction times between 15 and 360 mins to control the grafting levels of PS in the PS-GNR co-polymer. The resultant PS-GNR co-polymers were then blended into NR latex. The vulcanized NR compounds were investigated for the effect of PS grafting percentage in PS-GNR/NR compounds on mechanical properties, including tensile, tear strength and hardness. A core-shell structure was revealed with PS encapsulating the NR core via transmission electron microscopy. The polystyrene grafting percentage was determined to be 12.7%, 17.1%, 22.1% and 23.6% for polymerization times of 15 min, 60min, 120min, and 360 min, respectively. Addition of PS-GNR into NR exhibited biphasic behavior, resulting in a decrease in the tensile strength and tear strength. With further increase in grafting percentage of PS, the tensile strength and tear strength continues to decrease. The rigid chain of PS grafted onto NR surface reduced the elasticity of NR chain resulting in lower tear strength and the tensile strength. Fracture surface revealed a decrease in ductility of material with increasing grafting percentage of PS. On the other hand, modulus and hardness of PS-GNR/NR compounds were found to increase with increasing grafting percentage of PS. The addition of PS-GNR to rubber compound had shown an impact on dynamic behavior. With further increase in grafting percentage of PS in PS-GNR, an enhancement of storage modulus of rubber compound was clearly observed.

scholarly journals Preparation and Modification of Natural Rubber Blends Via Different Sulfur Curing Systems For Water Purification Treatment Usage

2020 ◽  
Author(s):  
Wenfa Dong ◽  
Ruogu Tang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Relative Volume ◽  
Curing Time ◽  
Water Industry ◽  
High Modulus ◽  
Elongation At Break ◽  
Tear Strength ◽  
Rubber Blends

<div>The water industry used NR was selected for blending with SBR. A series of NR/SBR vulcanizates were prepared through three different vulcanization systems, conventional vulcanization (CV), effective vulcanization (EV) and semi-effective vulcanization (SEV) respectively, basing on each formulation and optimum curing time. We examined the mechanical properties of NR/SBR vulcanizates including tensile strength, tear strength, elongation at break, modulus, Shore A hardnessand and relative volume abrasion. The results indicated that NR/SBR vulcanizates prepared in different systems differed in mechanical properties. Vulcanizates prepared via CV showed higher tensile and tear strength; vulcanizates prepared via EV had high modulus and hardness, and vulcanizates prepared via SEV performed high abrasion resistance. </div>

Sign in / Sign up

Export Citation Format

Share Document