scholarly journals Carbon Nanotubes Reinforced Natural Rubber Composites

2021 ◽  
Author(s):  
Apinya Krainoi ◽  
Jobish Johns ◽  
Ekwipoo Kalkornsurapranee ◽  
Yeampon Nakaramontri
Keyword(s):  
Functional Groups ◽  
Threshold Concentration ◽  
Ex Situ ◽  
Rubber Matrix ◽  
Silane Coupling Agents ◽  
Melt Mixing ◽  
Mixing Processes ◽  
Hybrid Filler ◽  
Natural Rubber Composites ◽  
Matrix Sensor

Several advanced methods have been introduced to disperse CNTs in the NR matrix. Various aspects highlighted in this chapter include the mixing processes such as melt mixing and latex mixing methods. As well as, formations of functional groups on the surfaces of CNT using silane coupling agents (i.e., ex-situ and in-situ functionalization). Moreover, hybrid CNT are beneficial to achieve better electrical conductivity of NR/CNT composites. These efforts are aimed to reduce the percolation threshold concentration in the NR composites for application as conducting composites based on electrically insulating rubber matrix. Sensor application is developed based on conducting NR composites. NR composites showed changing of resistivity during elongation termed as piezoresistivity. The most commonly used rubber matrices such as NR, ENR and IR are mixed with a combination of CNT and CB fillers as hybrid filler. The presence of linkages in the ENR composites results in the least loss of conductivity during external strain. It is found that the conductivity becomes stable after 3000 cycles. This is found to be similar to the NR-CNT/CB composite, while a few cycles are needed for IR-CNT/CB owing to the higher filler agglomeration and poor filler-rubber interactions. This is attributed to the polar chemical interactions between ENR and the functional groups on the surfaces of CNT/CB.

ENHANCEMENT OF ELECTRICAL CONDUCTIVITY AND FILLER DISPERSION OF CARBON NANOTUBE FILLED NATURAL RUBBER COMPOSITES BY LATEX MIXING AND IN SITU SILANIZATION

2016 ◽  
Vol 89 (2) ◽  
pp. 272-291 ◽  
Author(s):  
Yeampon Nakaramontri ◽  
Charoen Nakason ◽  
Claudia Kummerlöwe ◽  
Norbert Vennemann
Keyword(s):  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Threshold Concentration ◽  
Attenuated Total Reflection ◽  
Rubber Matrix ◽  
Melt Mixing ◽  
In Situ Functionalization

ABSTRACT Carbon nanotube (CNT)-filled natural rubber (NR) composites were prepared by melt and by latex mixing methods. Also in situ functionalization of CNTs with a silane coupling agent, namely bis(triethoxysilylpropyl)tetrasulfide (TESPT), was done to improve the filler–rubber interactions between CNT surfaces and rubber molecules. The grafting of TESPT molecules on CNT surfaces was confirmed by attenuated total reflection (ATR)–Fourier transform infrared (FTIR) spectroscopy and by the improvement of composite properties. Tensile properties were determined to assess the reinforcement efficiency of the CNTs in the composites. Also, electrical conductivity of the composites was measured to assess the formation of CNT networks (or connected conductive CNT pathways) in the rubber matrix. The results indicate that the composites prepared by latex mixing, in particular with the TESPT, had better tensile properties and electrical conductivities than the composites made by melt mixing. The lowest percolation threshold concentration, about 0.55 phr of CNTs, was observed in the latex–CNT composites, and three-dimensional network formations of CNTs in the rubber matrix were found with added TESPT, used by in situ functionalization. The improvement of filler–rubber interactions with the addition of TESPT was also examined by temperature scanning stress relaxation measurements, revealing the relaxation modulus, the relaxation spectrum, and an estimate of the cross-link density.

The Influence of Recycled Poly(ethylene Terephthalate) Powder on Fatigue Life, Thermal Stability, and Morphology of Halloysite Nanotubes (HNTs) and Precipitated Silica Filled Natural Rubber Composites

2011 ◽  
Vol 471-472 ◽  
pp. 628-633 ◽  
Author(s):  
H. Nabil ◽  
Hanafi Ismail ◽  
A.R. Azura
Keyword(s):  
Fatigue Life ◽  
Natural Rubber ◽  
Interfacial Adhesion ◽  
Halloysite Nanotubes ◽  
Volatile Matter ◽  
Rubber Matrix ◽  
Rubber Composites ◽  
Hybrid Filler ◽  
Degradation Temperature ◽  
Natural Rubber Composites

In this paper, the influence of recycled polyethylene terephthalate powder (R-PET) on fatigue life, thermal properties and micro-fracture surfaces of halloysite nanotubes (HNTs) and silica filled natural rubber composites have been studied. The total amount of hybrid filler in each formulation was kept constant at 20 parts per hundred rubber (phr). The final properties of HNTs/R-PET and Silica/R-PET compounds are considered separately and comparatively. Results indicated that the fatigue life of the natural rubber composites decreased with the replacement of these two fillers by R-PET powder. This observation might be due to the R-PET itself, which reduces the interfacial adhesion and wettability between rubber matrix and fillers. By replacing of HNTs and silica with R-PET powder, the thermal degradation of natural rubber composites was shifted to a lower temperature and the char residues was decreased, in which HNTs/R-PET composites expressed the higher temperature and char residues than silica/R-PET composites. This findings may be due to the HNTs/R-PET has less volatile matter than silica/R-PET that might enhance the degradation temperature of the natural rubber composites. SEM micrographs also exhibited weak interfacial adhesion when these two fillers were replaced with R-PET powder in NR composites.

Wet compounding with pyrolytic carbon black from waste tyre for manufacture of new tyre – A mini review

2021 ◽  
pp. 0734242X2110047
Author(s):  
Junqing Xu ◽  
Jiaxue Yu ◽  
Wenzhi He ◽  
Juwen Huang ◽  
Junshi Xu ◽  
...  
Keyword(s):  
Carbon Black ◽  
Pyrolytic Carbon ◽  
Research Progress ◽  
Rubber Matrix ◽  
Innovative Technology ◽  
Nano Materials ◽  
Natural Rubber Composites ◽  
Waste Tyres ◽  
Dry Mixing ◽  
Waste Tyre

Pyrolysis offers a more focused alternative to waste tyres treatment. Pyrolytic carbon black (CBp), the main product of waste tyre pyrolysis, and its modified species can be applied to tyre manufacturing realizing its high-value utilization. Modified pyrolytic carbon black/natural rubber composites prepared by a wet compounding (WC) and latex mixing process have become an innovative technology route for waste tyre remanufacturing. The main properties and applications of CBp reported in recent years are reviewed, and the main difficulties affecting its participation in tyre recycling are pointed out. The research progress of using WC technology to replace dry mixing manufacturing of new tyres is summarized. Through literature data and comparative studies, this paper points out that the characteristic of high ash content can be well utilized if CBp is applied to tyre manufacturing. This mini-review proposes a new method for high-value utilization of CBp. The composite mixing of CBp and carbon nano-materials under wet conditions is conducive to the realization of their good dispersion in the rubber matrix. This provides a new idea for customer resource integration and connection of industry development between the tyre production industry and waste tyre disposal management.

scholarly journals Combination of Self-Healing Butyl Rubber and Natural Rubber Composites for Improving the Stability

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 443
Author(s):  
Kunakorn Chumnum ◽  
Ekwipoo Kalkornsurapranee ◽  
Jobish Johns ◽  
Karnda Sengloyluan ◽  
Yeampon Nakaramontri
Keyword(s):  
Natural Rubber ◽  
Dynamic Mechanical Properties ◽  
Attenuated Total Reflection ◽  
Rubber Matrix ◽  
Self Healing ◽  
Mechanical And Electrical Properties ◽  
Natural Rubber Composites ◽  
Tan Δ ◽  
The Stability ◽  
Physical And Chemical

The self-healing composites were prepared from the combination of bromobutyl rubber (BIIR) and natural rubber (NR) blends filled with carbon nanotubes (CNT) and carbon black (CB). To reach the optimized self-healing propagation, the BIIR was modified with ionic liquid (IL) and butylimidazole (IM), and blended with NR using the ratios of 70:30 and 80:20 BIIR:NR. Physical and chemical modifications were confirmed from the mixing torque and attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR). It was found that the BIIR/NR-CNTCB with IL and IM effectively improved the cure properties with enhanced tensile properties relative to pure BIIR/NR blends. For the healed composites, BIIR/NR-CNTCB-IM exhibited superior mechanical and electrical properties due to the existing ionic linkages in rubber matrix. For the abrasion resistances, puncture stress and electrical recyclability were examined to know the possibility of inner liner applications and Taber abrasion with dynamic mechanical properties were elucidated for tire tread applications. Based on the obtained Tg and Tan δ values, the composites are proposed for tire applications in the future with a simplified preparation procedure.

COOPERATIVE EFFECTS OF EPOXIDE FUNCTIONAL GROUPS ON NATURAL RUBBER AND SILANE COUPLING AGENTS ON REINFORCING EFFICIENCY OF SILICA

2014 ◽  
Vol 87 (2) ◽  
pp. 291-310 ◽  
Author(s):  
W. Kaewsakul ◽  
K. Sahakaro ◽  
W. K. Dierkes ◽  
J. W. M. Noordermeer
Keyword(s):  
Natural Rubber ◽  
Functional Groups ◽  
Coupling Agent ◽  
Silica Content ◽  
Coupling Agents ◽  
Silane Coupling Agents ◽  
Cooperative Effects ◽  
Optimal Loading ◽  
Silane Coupling

ABSTRACT Polar functionality attached onto natural rubber has a significant impact on the reinforcing efficiency of silica. Parallel studies involving various levels of epoxidation on natural rubber (ENR) in the absence of bis-(triethoxysilylpropyl) tetrasulfide (TESPT) coupling agent, as well as a combination of ENRs with different loadings of TESPT, provide a better understanding of the various factors that influence the properties of silica-filled ENR compounds. Based on the overall properties, the best possible combination to optimize processability, to reduce filler–filler interaction, and improve vulcanization rate as well as vulcanizate properties, is to use ENR with an epoxide content in the range of 20–30 mol%, together with a small portion of TESPT, that is, 2–4 wt% relative to the silica content. This leads to a reduction of approximately 60–80% of TESPT when compared with the conventional NR compounds, where the optimal loading of TESPT was 9.0 wt% relative to the silica content.

scholarly journals Effect of silane treatment on mechanical properties and thermal behavior of bamboo fibers reinforced polypropylene composites

2020 ◽  
Vol 15 ◽  
pp. 155892502095819
Author(s):  
Qianting Wang ◽  
Yu Zhang ◽  
Weikang Liang ◽  
Jianjie Wang ◽  
Youxin Chen
Keyword(s):  
Mechanical Properties ◽  
Thermal Behavior ◽  
Functional Groups ◽  
Mechanical Test ◽  
Fiber Composite ◽  
Silane Treatment ◽  
Silane Coupling Agents ◽  
Polypropylene Composites ◽  
Bamboo Fibers ◽  
Pp Composites

In this work, the surface of the bamboo fibers (BF) was treated with three kinds of silane coupling agents terminated with amino functional groups (KH550), epoxy functional groups (KH560), and methyl functional groups (KH570) to improve fiber–matrix adhesion. The effects of silane treatment on the mechanical properties and thermal behavior of BF/polypropylene (PP) composites were investigated. Mechanical test results showed that the order of modification effectiveness was KH570 > KH550 > KH560. KH570 treated fiber composite exhibited the best mechanical properties. The tensile strength and flexural strength of 5 wt% KH570 treatment reached to 36.1 and 54.7 MPa, which were 15.4% and 23.6% higher than those of UBF/PP composites. Simultaneously, the thermal stability increased from 467.0°C (UBF) to 470.6°C (KH-570 treated BF). An increase in crystallization temperature (1.7°C) and a decrease in crystallinity (5.8%) occurred upon the addition of 5% KH570 silanes treated bamboo fibers.

scholarly journals A Green Approach for Preparing High-Loaded Sepiolite/Polymer Biocomposites

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 46 ◽  
Author(s):  
Barbara Di Credico ◽  
Irene Tagliaro ◽  
Elkid Cobani ◽  
Lucia Conzatti ◽  
Massimiliano D’Arienzo ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Rubber Matrix ◽  
Renewable Materials ◽  
Melt Mixing ◽  
Global Industry ◽  
Green Approach ◽  
Filler Network ◽  
Mechanical Performances ◽  
Synthetic Approaches

Global industry is showing a great interest in the field of sustainability owing to the increased attention for ecological safety and utilization of renewable materials. For the scientific community, the challenge lies in the identification of greener synthetic approaches for reducing the environmental impact. In this context, we propose the preparation of novel biocomposites consisting of natural rubber latex (NRL) and sepiolite (Sep) fibers through the latex compounding technique (LCT), an ecofriendly approach where the filler is directly mixed with a stable elastomer colloid. This strategy favors a homogeneous dispersion of hydrophilic Sep fibers in the rubber matrix, allowing the production of high-loaded sepiolite/natural rubber (Sep/NR) without the use of surfactants. The main physicochemical parameters which control Sep aggregation processes in the aqueous medium were comprehensively investigated and a flocculation mechanism was proposed. The uniform Sep distribution in the rubber matrix, characteristic of the proposed LCT, and the percolative filler network improved the mechanical performances of Sep/NR biocomposites in comparison to those of analogous materials prepared by conventional melt-mixing. These outcomes indicate the suitability of the adopted sustainable procedure for the production of high-loaded clay–rubber nanocomposites with remarkable mechanical features.

NATURAL RUBBER NANOCOMPOSITES BASED ON NEW FIBROUS NANOFILLERS WITH IMPROVED BARRIER PROPERTIES FOR USE IN TIRE INNERLINER APPLICATIONS

2020 ◽  
pp. 000-000 ◽  
Author(s):  
K. P. Surya ◽  
Sanjay Bhattacharya ◽  
Rabindra Mukhopadhyay ◽  
Kinsuk Naskar ◽  
Anil K. Bhowmick
Keyword(s):  
Natural Rubber ◽  
Crack Growth ◽  
Cellulose Nanofibers ◽  
Barrier Properties ◽  
Dynamic Mechanical Properties ◽  
Hybrid Nanocomposites ◽  
Melt Mixing ◽  
Hybrid Filler ◽  
Dynamic Mechanical ◽  
Growth Properties

ABSTRACT Hybrid nanocomposites were prepared by predispersion of new nanofibers such as aramid nanofibers, carbon nanotubes, silicon carbide nanofibers (SiC), cellulose nanofibers, and graphite nanofibers in natural rubber (NR) latex prior to melt mixing in an internal mixer to ensure the exquisite dispersion of nanofibers in NR. The competency of these nanofibers in reinforcing NR as well as enhancing its barrier properties has not been widely investigated. The fabricated nanocomposites showed enhanced curing as well as mechanical and dynamic mechanical properties. Morphology of the composites was analyzed through electron microscopy. The increase in tortuosity created by the presence of the hybrid filler system consisting of carbon black and nanofibers was studied using permeability models. At higher tearing energies, it was seen that the nanofiber-reinforced composites showed comparable crack growth properties; however, at lower energies, the fabricated composites exhibited higher crack propagation rates compared with the control compound when studied using a tear fatigue analyzer. The improved mechanical, dynamic mechanical, and barrier properties along with comparable fatigue crack growth properties offer an opportunity to apply these systems in high-end applications such as a thinner tire inner liner with a higher NR blend ratio, which can result in improved processability and reduced hysteresis, fuel consumption, and cost.

Filler-Elastomer Interactions. Part I: Silica Surface Energies and Interactions with Model Compounds

1991 ◽  
Vol 64 (4) ◽  
pp. 559-576 ◽  
Author(s):  
Meng-Jiao Wang ◽  
Siegfried Wolff ◽  
Jean-Baptiste Donnet
Keyword(s):  
Functional Groups ◽  
Phenyl Ring ◽  
Silica Surface ◽  
Rubber Matrix ◽  
Low Molecular Weight ◽  
Free Energies ◽  
Model Compounds ◽  
Surface Energies ◽  
Surface Areas ◽  
Degree Of Unsaturation

Abstract Inverse gas-solid chromatography, operated at infinite dilution, has been used to assess the surface energies of silicas, both fumed and precipitated. The dispersive components of the surface free energies of the silicas were calculated from the free energies of adsorption, corresponding to the —CH2— group, obtained from n-alkane adsorption. The specific components of the surface energies were evaluated separately by comparison of the free energies of adsorption of polar probes with those of n-alkanes, based on the surface areas covered by the probe molecules. The results indicate that while the dispersive components of silica surface energies is somewhat higher for the fumed silicas, the specific components are much higher for precipitated silicas, probably resulting from the higher silanol concentration on their surfaces. Moreover, the interaction able to take place between rubber matrix and the silicas are also estimated chromatographically from the adsorptions of low-molecular-weight analogs of elastomers. The free energies and enthalpies indicate that the interactions of functional groups with the fillers decrease in the order of nitrile, phenyl ring, double bond. The saturated rubber analogs show lower interactions with silicas. The lowest interactions of iso-alkanes imply poor interactions between butyl rubber and the fillers. As expected, the experimental data reflect an attenuation of polymer-silica interactions with decreasing content of functional groups and degree of unsaturation in NR, BR, SBR, and NBR.

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