Surface Modification Of Rubber Research Articles

Effect of oxidation of End-of-Life Tire Rubber as Aggregate Substitute in Cement Mortars.

In this paper the possible use of end-of-life tire rubber as a substitute for aggregate in cement mortars was explored. The aim of this paper was to investigate the effect of rubber surface modification by acidic treatment on the final properties of mortars. In fact, through treatment with sulfuric acid at moderate concentrations, a significant improvement in rubber wettability and interaction with cement has been observed. The compressive strength of mortars containing 15%w treated rubber as a replacement of natural aggregate is comparable to those of standard mortars. This suggests that surface modification of rubber plays a very important role in the possible integration of end-of-life tire rubber in mortar and concrete. The results presented in this paper confirm that recycling in mortar and concrete is a promising way for improving rubber waste management and sustainable innovation in the construction industry.

Sustainable approach of promoting impact resistant rubberized geopolymer by reducing the embodied emission rate of climate changing substances

Waste disposal and green house gas emission are the two main threats to the today’s environment which demands the need for sustainable and greener construction all over the world. This initiated the recycling and reusing of predominant waste materials such as fly ash, rubber waste, etc, in the construction industry without affecting the quality. In this paper, a novel method of rubber surface modification process was developed by using natural eggshell catalysing technique in order to establish a impact resistant rubberized cementless green mortar without compromising the mechanical strength. At the end of the research, it was observed that the developed eggshell catalysing technique transformed the rubber surface into extremely hydrophilic by reducing the water contact angle from 134° to 10° and make the surface ready to create strong interfacial bond with polymeric gels. This extreme hydrophilic nature of the eggshell catalysed rubber resulted in the improved workability and 95.7% recovery in strength. Also, the calcium rich eggshell layer imparts the excellent stress dispersion effect and structural integrity which offers the 2.67 times improved impact resistance. In addition to this, the use of eggshell catalysed rubber aggregates significantly reduced the embodied ECO2 emission rate and consumption rate of natural fine aggregates respectively by 1.6 kgCO2/kg and 58 kg in every cubic meter of construction which leads to the sustainable and environmental friendly approach in the promotion structures subjected to dynamic loading such as bridges, girders, abutments, lighthouses etc.

THEORETICAL MODELING OF THE NUCLEATION OF INTERNAL LATENT THERMAL DEFECTS IN A BITUMINOUS MEDIUM WITH RUBBER INCLUSIONS

The current state and progress of the technology and science associated with the reuse and recycling of the tyre rubber worldwide in the road industry compels to study more thoroughly high and low temperature performance of the road bitumen modified with rubber crumbs, permitting to understand influence of the temperature, rubber grain size and mixture bitumen-rubber modification on the composite strength and sustainability. Below, these issues are studied taking into account the peculiarities of the thermomechanical properties of rubber associated with its low rigidity when changing shape, practical incompressibility when changing volume, and low (zero or even negative) coefficient of linear thermal expansion. The purpose of the study is to determine the reasons leading to a violation of the strength of asphalt concrete materials with admixtures of rubber crumb. For this purpose, the influence of the incompatibility of thermomechanical characteristics (moduli of elasticity, Poisson's ratios and coefficients of thermal expansion) of bitumen and rubber on the concentration of additional internal thermal stresses in the system caused by seasonal and daily temperature changes is analyzed. Using the relations of the theory of thermoelasticity, a mathematical model of thermal deformation of crumb rubber in a bitumen medium has been constructed. With the possibility of complete and surface modification of rubber with bitumen, solutions for three-phase media are constructed, which make it possible to trace the influence of the parameters of each phase on the thermal stress fields in the system. It has been established that additional thermal stresses in bitumen, due to the thermomechanical incompatibility of the physical parameters of the phases, are concentrated in the zone of its contact with the surface of the rubber crumb and can cause defects and chippings in it. The influence of the effect of modifying rubber crumb with bitumen and of the depth of its penetration into crumb of different sizes on reducing thermal stresses in the system and increasing its sustainability is considered.

Mesoporous aluminum impregnated rubber seed shell waste enriched with calcium as adsorbent material for the removal of microbial DNA in aqueous solution

Water contamination by pathogens and diseases induced by these pathogens is a major water quality issue all over the world. Poor public health has been linked to tap water polluted with DNA harboring antibiotic resistance genes sequence. According to HSAB concept, surface modification of rubber seed shell waste with alumina (AIRSS) as novel agro-waste adsorbent creates more active surface constituents for DNA adsorption. The proximate, ultimate and EDAX analysis provides the percentage levels of ash concentration, volatile, moisture and fixed carbon content, elemental composition present in the adsorbent. The structural features of AIRSS were determined using FT-IR, SEM and XRD. In order to improve reaction conditions, the effect of pH, temperature, adsorbent amount, and reaction time is also examined. The highest percent of DNA removal (92.5%) was achieved at the optimum conditions: 2 g/L at pH 4, contact time 120 minutes as compared to the conventional methods. The DNA adsorbs onto the surface of AIRSS through physical (vander Waals force) and chemical interactions, as demonstrated by kinetics and spectroscopic analyses. Changes in enthalpy (H), free energy (G), and entropy (S) indicate that adsorption is a spontaneous and exothermic process, according to thermodynamic parameters. The results of the experiments showed that the prepared AIRSP adsorbent could be used to remove DNA from water. The efficacy of AIRSS for the removal of DNA has decreased after nine months of storage and use. Low pH and the presence of AIRSS improved DNA-AIRSS adsorption, according to our findings.

ADVANCES IN TECHNIQUES AND APPLICATIONS OF RUBBER SURFACE GRAFTING MODIFICATION

ABSTRACT To meet the requirement in the application of medical devices, composites, biomaterials, corrosion resistance, and selective adsorptions, rubber surface modification is usually indispensable. Grafting treatment is one of most significate treatment methods. In this paper, we focus on rubber surface grafting modification, including grafting techniques and applications. Different grafting methods—including monomer grafting polymerization and coupling reaction—are covered and compared briefly. The related applications of surface grafting modification techniques, such as improving compatibility of waste rubber as fillers, hydrophobicity and lipophilicity of sponge rubber for oil–water separation, biocompatibility of rubber in the medical field, and forming surface patterns, are demonstrated in detail. The new research directions of surface grafting techniques as well as main challenges in application are also discussed.

Improving rubber concrete strength and toughness by plasma‐induced end‐of‐life tire rubber surface modification

AbstractThis study evaluates the effectiveness of using different plasma treatments to favor the compatibility between rubber and a cement matrix in composites, thus leading to a different surface reactivity of the rubber component. Plasma‐treated rubbers were introduced into two different types of concrete. Mechanical tests highlighted that Portland concrete composites filled with N2/H2 plasma‐treated rubber had increased flexural strength, toughness, and compression strength compared to composites containing untreated rubber. A scaling law is also proposed to qualitatively discriminate between related effects due to topological/roughness or intrinsic/chemical adhesion modifications. Plasma treatment can improve both intrinsic adhesion and roughness of the rubber–cement interface and thus the overall concrete strength and toughness.

Surface modification of rubber seed shell activated carbon with malic acid for high CO2 adsorption

Carbon dioxide (CO2) has been stated as one of major contributor to climate change and affects marine ecosystems. Among other CO2 capturing technology, adsorption is widely used due to its numerous advantages. Rubber seed shell (RSS), an agriculture waste from rubber plantation was used as precursor for preparing activated carbon (AC) by chemical activation using Malic acid as activating agent for CO2 adsorption. In this research, the AC was characterized and analysed by SEM, Micrometric ASAP 2020, TGA and FTIR instruments. The optimum condition was found at activation temperature of 600 °C, sample A. Results from specific surface and porosity analyzer shows the AC total pore volume, specific surface area and diameter were 0.2635 cm3/g, 480.5692 m2/g and 2.1937 nm, respectively. The CO2 adsorption studies showed the CO2 uptake for the AC was 2.26 mmol/gwhich is better most agricultural wastes’ and commercial AC. It was found that malic acid helps to prolong the thermal stability of AC. The presence of a new FTIR peak in samples indicated N-H stretching and C=N stretching might due to remaining malic acid on the surface which increased the CO2 affinity and was an attractive source for CO2 adsorption applications.

Crumb waste tire rubber surface modification by plasma polymerization of ethanol and its application on oil-well cement

Crumb waste tire rubber (WTR) was pretreated by oxygen low temperature plasma (LTP) and modified by LTP polymerization process of ethanol monomer to improve the adhesion property with oil-well cement matrix and the mechanical properties of cement. The surface properties of modified crumb WTR and the mechanical properties and structures of modified oil-well cement were investigated by means of contact angle measurement, dispersion test, attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), mechanics performance tests, permeability test and scanning electron microscopy (SEM). It was demonstrated that LTP treatment changed both the surface composition and roughness. The contact angle of pretreated crumb WTR dramatically fell from 122° to 34°, and sample with ethanol LPT polymer film decreased even further to 11°. The ATR-FTIR and XPS analysis results demonstrated that hydrophilic groups, such as –COOH, C–OH, and –CHO, were introduced on the WTR surface. The oxygen atomic percent increased from 8.11% to 14.50% and 24.83%. The mechanical properties, porosity and permeability of raw cement were compared to samples modified by untreated crumb WTR, pretreated crumb WTR and ethanol LTP polymerization treated crumb WTR. It was found that after 28 days, the compressive strength of the samples with the untreated crumb WTR decreased to 80% with respect to raw cement. The tensile strength and flexural strength also had a slight reduction compared with the raw cement. On the contrary, after 28 days, the tensile strength of cement modified by LTP polymerization treated WTR increased 11.03% and 13.36%, and the flexural strength increased 9.65% and 7.31%, respectively. A decrease in the compressive strength also occurred but was inconspicuous. A tight interface bonding for ethanol LTP polymerization treated WTR with cement matrix was observed via an SEM image.

Surface modification of crumb rubber and its influence on the mechanical properties of rubber-cement concrete

In this paper, a surface modification method was proposed to introduce strong polarity groups to rubber surface to generate a strong chemical bond between the rubber and the cement matrix. Rubber was first oxidized with KMnO4 solution and then sulphonated with NaHSO3 solution. The Fourier transform-infrared (FT-IR) spectra and contact angle measurement showed that the oxidation and sulphonation process introduced a large number of hydrophilic hydroxyl and sulfonate to crumb rubber and decreased the contact angle between rubber surface and water, thus greatly improved the interfacial bonding strength between crumb rubber and cement paste. After the rubber surface modification, the adhesion strength of the rubber and cement paste was increased by 41.1%. It was also found in the mechanical tests that the rubber surface modification was quite useful to enhance the compressive strength and impact strength of rubber-cement concrete. The compressive strength of the concrete with 4% modified rubber powder was 48.7% higher than that with ordinary rubber powder. Based on the results, it is concluded that the surface modification of crumb rubber with KMnO4 and NaHSO3 solutions is an effective method to improve the mechanical properties of rubber-cement concrete.

RTV silicone rubber surface modification for cell biocompatibility by negative-ion implantation

A negative cluster ion implantation system was built on the injector of a GIC4117 tandem accelerator. Next, the system was used to study the surface modification of room temperature vulcanization silicone rubber (RTV SR) for cell biocompatibility. The water contact angle was observed to decrease from 117.6° to 99.3° as the C1− implantation dose was increased to 1×1016ions/cm2, and the effects of C1−, C2− and O1− implantation result in only small differences in the water contact angle at 3×1015ions/cm2. These findings indicate that the hydrophilicity of RTV SR improves as the dose is increased and that the radiation effect has a greater influence than the doping effect on the hydrophilicity. There are two factors influence hydrophilicity of RTV: (1) based on the XPS and ATR-FTIR results, it can be inferred that ion implantation breaks the hydrophobic functional groups (SiCH3, SiOSi, CH) of RTV SR and generates hydrophilic functional groups (COOH, OH, Si(O)x (x=3,4)). (2) SEM reveals that the implanted surface of RTV SR appears the micro roughness such as cracks and wrinkles. The hydrophilicity should be reduced due to the lotus effect (Zhou Rui et al., 2009). These two factors cancel each other out and make the C-implantation sample becomes more hydrophilic in general terms. Finally, cell culture demonstrates that negative ion-implantation is an effective method to improve the cell biocompatibility of RTV SR.

Surface modified used rubber tyre aggregates: effect on recycled concrete performance

Although research has found that using rubber in concrete will enhance its resilience and reduce its density, the significant loss of strength owing to lack of bonding has remained unresolved. This study considers how to minimise the loss of strength of concrete with used rubber tyre crumb aggregates and investigates the improvement of water permeability resistance that may consequentially develop. A surface of rubber crumb was modified by soaking in the saturated sodium hydroxide solution or silane coupling agent (SCA) before using. Up to 20% of natural fine aggregate was volumetrically replaced with treated rubber crumb. Experimental results show higher compressive and flexural strengths, Young's modulus and water permeability resistance from the samples with SCA-treated rubber than with as-received or sodium-hydroxide-treated rubber. X-ray diffraction pattern analyses indicate almost no change in crystalline phase for the rubber surface modification. Microscopic inspections show an enhanced rubber-matrix adhesion with the use of SCA. Results of mercury intrusion porosimetry reveal that concrete with SCA-treated rubber has a similar pore size distribution to the other three mixes, but achieves the lowest porosity and highest tortuosity, resulting in the best water permeability resistance. A brief cost analysis suggests that this method of surface modification is economically viable.

トライボロジー特性改善のための機能性表面の創製

In order to overcome the tribological issues in friction, wear and adhesion, tribological functional surfaces were fabricated as classified as surface modification, coatings and texturing. In this paper, I explain the control method of friction and adhesion with plasma and fluoride method as surface modification of rubber. Also ultra low friction and low adhesion was happened by friction induced nanometer thickness transformed layer and super hydrohobocity of DLC respectively. And the principles of the improvement of tribological properties with texturing were explained briefly.

Road Performance of Silane Coupling Agent Modified Rubber Concrete

Silane coupling agent can be built a "molecular bridge" between organic molecules and inorganic molecules on the rubber surface modification, the binding ability of rubber particles and cement based materials has increased, thus improving the mechanical properties of rubber concrete. Study on silane coupling agent dosage as cementations material quality of 0.5%, the modification effect of coupling agent on the rubber concrete, compared with changes in mechanical properties of unmodified rubber concrete, and analysis the test concrete fracture pressure ratio, using the ultrasonic detector to measure ultrasonic velocity in concrete, to calculate the dynamic modulus and study its road noise performance.

Experimental Study on Ratio of Bending-Compressive Strength of the Crumb Rubber Concrete Modified by Latex

The cementitiousness between rubber particles and cement-based material could be raised because of the surface modification of rubber,thus enhance the mechanical property of crumb rubber concrete and improve the interface effect of rubber particles.We had researched the change regulation about the ratio of bending-compressive strength of the crumb rubber concrete modified by latex,the concrete with various quantity of rubber,under the condition dosage of latex is 0.5% of cement quality.The result of experimental prove that,compressive strength, splitting tensile and flexural strength could be enhanced because of latex injecting,and the ratio of bending-compressive strength could be enhanced at the same time.

Experimental Study on the Mechanical Properties of the Crumb Rubber Concrete Modified by Silane Coupling Agent

Organic molecule and Inorganic molecular could be bind by silane coupling agent,the cementitiousness between rubber particles and cement-based material could be raised because of the surface modification of rubber,thus enhance the mechanical property of crumb rubber concrete.We had researched the change regulation of Mechanical Properties,such as compressive strength,splitting tensile strength and flexural strength of the Crumb Rubber Concrete Modified by silane coupling agent with various quantity of rubber,under the condition Dosage of silane coupling agent is 0.5% of cement quality.

Experimental Study on Proportion of Tensile Strength and Compressive Strength of the Crumb Rubber Concrete Modified by Latex

The cementitiousness between rubber particles and cement-based material could be raised because of the surface modification of rubber,thus enhance the mechanical property of crumb rubber concrete and improve the interface effect of rubber particles.We had researched the change regulation of the ratio between tensile strength and compressive strength of the Crumb Rubber Concrete Modified by latex,the concrete with various quantity of rubber,under the condition Dosage of latex is 0.5% of cement quality.The result of Experimental prove that,compressive strength, splitting tensile and flexural strength could be enhanced because of latex injecting,and the ratio between tensile strength and compressive strength could be enhanced at the same time.

Surface modification of vulcanized styrene–butadiene rubber with trichloroisocyanuric acid solutions of different active chlorine contents

Two solutions in ethyl acetate (EA) containing 3 wt% trichloroisocyanuric acid (TCI) from two different suppliers having different active chlorine contents were used as chemical surface treatment of a vulcanized styrene–butadiene (SBR) rubber. The amount of active chlorine in the TCI solutions was evaluated by iodine titration. The changes produced in the SBR rubber were monitored by using ATR-IR spectroscopy, scanning electron microscopy and contact angle measurements. The adhesive strength variation in SBR rubber/polyurethane adhesive joints was consistent with the variation in surface chemistry, wettability, and topography of the treated SBR rubber. The increase in time between TCI solutions preparation and SBR treatment allowed an increase in adhesive strength, the highest value corresponded to the joint produced with the SBR rubber treated with TCI solution prepared for 60 days. On the other hand, the active chlorine concentration in the TCI solutions was not the only parameter determining the adhesion of SBR rubber, as the highest adhesive strength was not achieved by treating the rubber with the TCI solution with higher active chlorine content. Therefore, the effectiveness of the halogenation treatment of rubber was not always higher by using a halogenating solution with higher active chlorine content. Furthermore, the chlorine concentration in the TCI solutions was not stable in the course of time, 60 days after preparation of solutions was the most efficient chlorinating solution for SBR rubber surface modification.

Surface modification of rubber (Hevea brasiliensis) leaves for the adsorption of copper ions: kinetic, thermodynamic and binding mechanisms

AbstractBACKGROUND: This research describes the adsorption of copper ions from aqueous solutions following the modification of rubber (Hevea brasiliensis) leaves with formaldehyde solution. The main objectives of this research were to identify the binding mechanisms of copper ions on the chemically modified rubber leaves by spectroscopic techniques and to investigate the effects of several important physicochemical parameters such as pH, copper concentration, contact time, adsorbent dose and temperature on copper removal.RESULTS: Based on a kinetic study, the pseudo‐second‐order model was found to fit the experimental results well, while the Boyd kinetic model indicated that the rate‐determining step was due to film diffusion. Adsorption isotherms were modelled by the Langmuir and Freundlich isotherm equations, with the former providing a better fit for the data. Based on the Langmuir model, the maximum adsorption capacities of Cu(II) ions at 300, 310 and 320 K were 8.36, 8.61 and 8.71 mg g−1, respectively. Thermodynamic parameters such as the Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy changes (ΔS°) were calculated. The adsorption process was spontaneous as the values of ΔG° were negative, and endothermic as higher adsorption capacities were recorded at higher temperatures. More than 80% of copper ions bound on the adsorbent were able to be desorbed using 0.02 mol L−1 HCl, HNO3 and EDTA solutions. Besides ion exchange, surface complexation could also play a major role in copper binding.CONCLUSION: Due to its relative abundance and satisfactory adsorption capacity, the modified rubber leaves can be considered as a good low‐cost adsorbent for removing copper ions from dilute aqueous solutions. Copyright © 2008 Society of Chemical Industry

Modification of rubber surface by UV surface grafting

Rubber surface is subjected to ultraviolet radiation (UV) in the presence of allylamine and radiation sensitizer benzophenone (BP). Fourier transform infrared spectral studies reveal the presence of allylamine on the surface. The presence of irregular needle shapes on the surface as observed in scanning electron micrographs also confirms the polymerized allylamine on the surface. Allylamine coatings have been further confirmed from atomic force microscopy (AFM) analysis. Thermogravimetric analysis (TGA) reveals that allylamine coating on the rubber surface lowers the thermal degradation rate. The contact angle between the water and rubber surface decreases for the modified rubber surface confirming the surface modification due to UV surface grafting.