Waste Rubber Powder Research Articles

Styrene butadiene-based blends containing waste rubber powder: Physico-mechanical effects of mechanochemical devulcanization and gamma irradiation

Waste rubber (WR) powder was introduced in a two-roll mill in the presence of various ratios of curatives to develop sheets of devulcanized waste rubber (DWR). The selected product was investigated by FTIR, TGA and SEM. In a roll mill and hot press, styrene butadiene rubber (SBR) gum was differentially replaced by DWR feed ratios, and thereafter irradiated with gamma rays. The mechanical parameters of the developed blend were examined. Oil resistance and thermogravemetric behavior were discussed. Remarked improvement in the mechanical, thermal and physical parameters of SBR was generally determined by the incorporation of DWR and gamma irradiation.

Mechanochemical devulcanization and gamma irradiation of devulcanized waste rubber/high density polyethylene thermoplastic elastomer

Waste rubber (WR) powder was introduced in a two-roll mill in the presence of various ratios of curatives to develop sheets of devulcanized waste rubber (DWR). The product has been investigated by FTIR, TGA and SEM. A thermoplastic elastomer (TPE) was prepared by blending the obtained DWR with high density polyethylene (HDPE) at different feed ratios under conditions of gamma irradiation, 25, 50, 100, and 150kGy. The mechanical parameters of the blend: tensile strength, elongation at break, and hardness (Shore D) were studied. In addition, blend characterization using FTIR spectra, gel fraction, TGA and SEM was discussed.

Mechanical and dynamic mechanical properties of natural rubber blended with waste rubber powder modified by both microwave and sol–gel method

AbstractWaste rubber powder (WRP) was modified by microwave, sol–gel method, and both microwave and sol–gel method, respectively. The mechanical and dynamic mechanical properties of natural rubber (NR)/modified WRP composite were investigated. The influence of bis‐(3‐(triethoxysilyl)‐propyl)‐tetrasulfide (TESPT) content on curing characteristics and mechanical properties of vulcanizate was also studied. The results showed that NR/WRP modified by both microwave and sol–gel method composite owned the best mechanical properties. Rubber processing analyzer was used to characterize the interaction between silica and rubber chains and the dispersion of silica. With increase of TESPT content, the Payne effect decreased. Scanning electron microscopy indicated the coherency and homogeneity of in situ generated silica filled vulcanizate. Dynamic mechanical analyzer showed that NR/WRP modified by both microwave and sol–gel method composite with 5 phr TESPT exhibited the lower tan δ at temperature range of 50–80°C, compared with composite without TESPT and the higher tan δ at temperature of 0°C, compared with the conventional modification of WRP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Modification and Application of Waste Rubber Powder

Modification and Application of Waste Rubber Powder

Composites based on waste rubber powder and rubber blends: BR/CSM

Blend of polybutadiene (BR) rubber with varying ratios of chlorosulphonated polyethylene rubber (CSM), BR/CSM, keeping the total waste rubber powder (WRP) content constant at 50phr (parts per 100 rubber) have been prepared on a laboratory-size (300×600mm) two-roll mixing mill maintained at 40±5°C. The mechanical properties, namely tensile strength (TS), tensile modulus at 100% elongation (M100), elongation at break (Eb%) and hardness have been followed up as a function of irradiation dose (dose rate of 10kGyh−1 and total absorbed dose of 100, 200, 300 and 400kGy) as well as blend composition. The results indicated that the addition of CSM has improved the properties of BR/CSM rubber blends waste rubber powder filled composites. The improvement in mechanical properties of the BR/CSM/WRP (50/50/50) rubber blends is in correlation with homogenous WRP distribution which has been assigned by scanning electron microscopy. Also BR/CSM rubber blends waste rubber powder filled composites are thermally and irradiation more stable than BR and CSM rubbers alone.

Reinforcement of waste rubber powder by zinc dimethacrylate

The reinforcing effect of in situ prepared zinc dimethacrylate (ZDMA) on the waste rubber powder (WRP) was investigated by the mechanical/morphological tests and the vulcanization analysis. Scanning electronic microscope and polarizing microscope analyses showed that there were ZDMA particles in the modified WRP vulcanizate. The ZDMA improved the interaction between WRP particles and increased the mechanical properties of WRP vulcanizate. The cross-linking kinetics of ZDMA-modified-WRP was studied by cure curves at different temperature. The results showed that the ZDMA participated in the cross-link reaction of WRP particles and increased the cure rate constant and decreased the cure activate energy. The tensile behaviors for different modified WRP vulcanizates also implied the improvement of ZDMA to the interaction of the WRP particle. Besides, the ZDMA-modified-WRP had reinforcing effect on the natural rubber vulcanizate in comparison with the negative effect of other modified WRP.

Review on the Broken Three-Dimensional Network Modification Methods of Waste Rubber Powder

The modification methods of waste rubber powder(WRP) which contain mechanochemical, microwave, ultrasonic, devulcanization in supercritical material and microbial devulcanization method through cutting off three-dimensional network are described. More emphasis is put on devulcanization mechanism and the defects of each method as the devulcanization process is often accompanied with the main rubber chains degradation are also discussed. When modified WRP is added into rubber matrix, the mechanical properties of composite and compatibility between virgin rubber and WRP are improved. So the mode of core modification on WRP is built, through the broken three-dimensional network modification methods of WRP.

Research on the Influences of the Molding Processes of TOR Asphalt Rubber Mixtures upon the Pavement Performance

It’s a chemical method that adding TOR into asphalt rubber to be TOR asphalt rubber mixture. In this study, 70# basic asphalt from Nanjing Jinling Company and 60 mesh waste rubber powder from Jiangyan Honglei Company were chosen for the SMA13 grading and SUP13 grading by the best preparation technology. The high temperature stability, anti-cracking performance and water stability of TOR asphalt rubber mixture were studied and the influence of dry and wet molding process on road performance of TOR asphalt rubber mixture was compared. The results show that both the dynamic stability and the low-temperature cracking performance of wet forming specimens are better than the dry process. The water stability of wet molding process is also slightly better than the dry process. And expansion rate tests were carried out on asphalt mixtures prepared by dry and wet forming processes on continuous gradation and discontinuous gradation to validate the applicability of discontinuous gradation to asphalt rubber.

Aging properties and mechanism of the modified asphalt by packaging waste polyethylene and waste rubber powder

For the consideration of the environmental and economic issues, retrieved packaging waste polyethylene and waste rubber powder were selected as modifiers to modify the ordinary oil asphalt, and the rotating film oven test was adopted to study the aging process of the modified asphalt. The results showed that the performance of the modified asphalt deteriorated, as indicated by the increase in the softening point and the reduced ductility and penetration. However, compared with nonmodified asphalt, the rangeability of the performance indicators of the modified asphalt before and after aging became narrow, indicating that the aging properties of the modified asphalt were improved. In the modified asphalt system, the swelling of the polymer modifiers was caused by the absorption of the light components of the asphalt, thereby reducing the formation of asphaltenes in the aging process. The polymer modifiers absorb the light oil of the asphalt, which can reduce the content of free radicals and improve the aging properties of the asphalt. In addition, the waste rubber power containing antioxidants and anti‐ozone agents effectively improves the antiaging properties of the asphalt. Copyright © 2012 John Wiley & Sons, Ltd.

Impact of antimony trioxide on the physico‐mechanical and flammability properties of irradiated recycled rubber powder and waste polyethylene composites

AbstractThe physicomechanical behavior and flammability properties of waste polyethylene and recycled waste rubber powder blend (WPE/RWRP/MA) filled with antimony trioxide (Sb2O3), at different contents 5, 10, 15, and 20 wt %, and irradiated with different gamma radiation doses, namely 50, 75, 100, and 150 kGy, were investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and limiting oxygen index (LOI) measurements. Tensile strength, elongation at break, elastic modulus, hardness, swelling properties, and electric conductivity behaviors were also investigated. Experimental results emphasized that Sb2O3 particles retard degradation and flammability of the composite. The LOI increases from 16 to 20.9 with 20 wt % Sb2O3 specimen irradiated with 150 kGy. Improvement in thermal stability at conditions of 15 wt % Sb2O3 and a dose of 75 kGy was demonstrated by TGA.DSC measurements showed that Tm significantly increased in the presence of the filler. Mechanical characterization tests showed a significant increase in tensile strength within the range 5–10 wt % Sb2O3. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Swelling process of rubber in asphalt and its effect on the structure and properties of rubber and asphalt

This paper deals with the mechanism of waste crumb rubber modified asphalt through simulating the swelling of rubber in asphalt using SBR sheet instead of waste rubber powder. Four groups analysis (SARA – saturates, aromatics, resins and asphaltines), XPS (X-ray Photoelectron Spectroscopy) and DSC (Differential Scanning Calorimeter) were used to characterize the structure and properties of asphalt and rubber in swelling experiment. The results reveal that the swelling of rubber in asphalt moved from a fast-growing process then level off to the equilibrium, and rubber absorbed only the light components in asphalt. The amount of asphalt components affects the properties of asphalt. During the swelling process, the amount of light constituents decreased accompanied by an increased softening point and decreased ductility and penetration.

Effect of epoxidized natural rubber on thermal properties, fatigue life, and natural weathering test of styrene butadiene rubber/recycled acrylonitrile‐butadiene rubber (SBR/NBRr) blends

AbstractThe utilization of waste rubber powder in polymer matrices provides an attractive strategy for polymer waste disposal. Addition of recycled acrylonitrile‐butadiene rubber (NBRr) in rubber compounds gives economic (lowering the cost of rubber compounds) as well as processing advantages. In this study, the properties of styrene butadiene rubber (SBR)/NBRr blends with and without epoxidized natural rubber (ENR‐50) as a compatibilizer were determined. The results such as thermal gravimetric analysis (TGA), fatigue life, and natural weathering test of SBR/NBRr blends with and without ENR‐50 were carried out. Results showed that TG thermograms of SBR/NBRr blends with ENR‐50 show lower thermal stability compared blends without ENR‐50. The incorporation of ENR‐50 into SBR/NBRr blends has reduced char residue compared SBR/NBRr blends without ENR‐50. The incorporation of ENR‐50 in SBR/NBRr blends has increased the rigidity of the blends thus lowering the fatigue life. The increment in tensile properties retention of SBR/NBRr blends with ENR‐50 indicated the enhancement on weathering resistant. The surfaces of SBR/NBRr blends with ENR‐50 after 6 months exposure showed a minimal severity of crack compared with SBR/NBRr blends without ENR‐50. It revealed that the scale of cracks has reduced indicating well‐retaining interfacial adhesion between SBR and NBRr with the presence of ENR‐50 as a compatibilizer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Graft polymerization of styrene onto waste rubber powder and surface characterization of graft copolymer

The surface of waste rubber powder (WRP) was graft-modified with styrene (St) by bulk polymerization method. The effects of styrene content, initiator mass, time of reaction, and temperature on the graft efficiency were investigated. The results showed that the graft efficiency (%) was highest when 89 wt% styrene and 0.11 g of initiator were added for reaction time of 25 h at 85 °C. The surface of graft-modified rubber powder was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy dispersive X-ray (EDXS) analysis, and thermogravimetric (TG/DTG) analysis. The results showed that polystyrene (PS) was grafted onto waste rubber powder, which formed a WRP/PS core–shell structure.

Technological Properties of Poplar Particle/Waste Rubber Powder Composites

The hot-pressing technology for the poplar particle /waste rubber powder composites was studied using the poplar particle and waste rubber powder as raw materials. Effects of waste rubber powder content, hot-pressing time, hot-pressing temperature, resin content and board density were analyzed. The hot-pressing technology was better than molding technology. The optimal technological parameters of hot-pressing technology were obtained as board density0.8g/cm³, resin content3%, hot-pressing temperature160°C, hot-pressing time 7min , waste rubber powder content 30%. The testing results showed that the mechanical performances of the poplar particle /waste rubber powder composites made by the hot-pressing technology could achieve the Chinese National Standard for particle board.

Gamma irradiation of treated waste rubber powder and its composites with waste polyethylene

AbstractThis investigation was undertaken to prepare composites of waste polyethylene (WPE) with concentrations of 5, 15, and 25 wt% of waste rubber powder (WRP) and to determine the changes in properties of these composites before and after treatment of the WRP with acrylic acid. Mechanical, physical, thermal, FTIR, and SEM investigations showed that treated and gamma‐irradiated WRPs gave better properties than untreated ones. Hence, a simple method to prepare composites based on recycled polyethylene and waste rubber powder could be achieved without using expensive treatment of the polymeric wastes. J. VINYL ADDIT. TECHNOL., 2011. © 2011 Society of Plastics Engineers

Hybrid modified rubber powder and its application in cement mortar

This research focused on using the waste rubber powder as a kind of regenerate resources to improve the mechanical properties of cement mortar. The two kinds of hybrid modified rubber powder TRP and ATRP were prepared by sol-gel method and then used in cement mortar. The structures and properties of them were studied. It is shown that the nano Si-O-Si network is generated in TRP and ATRP networks and the hydrophilic group is grafted on the surface of ATRP. The mechanical properties of rubber-treated mortar (RTM) were tested and the microstructures of them were also studied. Compared to the mortars with unmodified rubber powders (RP), NaOH treated rubber powder (SRP) and coupling agent treated rubber powder (CRP), the RTM with ATRP has the highest compressive strength and flexural strength. The stress-strain curves shown that the peak of stress of RTM with ATRP is increased and indicated the higher compression deformation and toughness. It is found that the interfacial adhesion between the ATRP and cement mortar is increased distinctly by SEM, which results in enhanced ductility and mechanical properties of RTM with ATRP.

Effect of carbon black on the properties of irradiated recycled polyamide/rubber waste composites

Abstract In the present study, the synergistic effect of carbon black (CB) content % and gamma irradiation on some mechanical, thermal, chemical stability and micro-structural properties of the moulded waste polyamide copolymer/recycled waste rubber powder (rPA/WRP) 50/50 was investigated. The ternary composites of CB concentrations, 6, 12, 18, and 24 wt.%, were irradiated with doses of 50, 100, 150 and 200 kGy. The composites mechanical properties: tensile strength, elongation at break, and hardness, and the thermal properties: melting temperature ( T m ) and (Δ H ) were measured. Also, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), swelling and chemical stability were investigated.

Influence of talc content on some properties of gamma irradiated composites of polyethylene and recycled rubber wastes

AbstractIn this study, the synergistic effect of talc content % and gamma irradiation on some mechanical, thermal, electrical resistance, and microstructural properties of the molded waste polyethylene/recycled waste rubber powder (WPE/RWRP) 60/40 was investigated. The ternary composites of talc concentrations, 5, 10, 15, and 20 wt %, were irradiated with doses of 50, 75, 100, and 150 kGy. The composites mechanical properties: tensile strength, elongation at break, and elasticity modulus, and the thermal properties: melting temperature (Tm) and (ΔH) were predicted. Also, scanning electron microscopy, thermogravimetric analysis, and electric conductivity were investigated. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Studies on mechanical, thermal and morphological properties of irradiated recycled polyamide and waste rubber powder blends

Abstract The aim of this article was to show the effect of gamma irradiation on mechanical and thermal properties of recycled polyamide (rPA) copolymer blended with different content of waste rubber powder (WRP). In order to study the structural modifications of prepared blends have been subjected to irradiation doses up to 200 kGy were applied to all samples. Non-irradiated blends were used as control samples. Mechanical properties, namely, tensile strength (TS), elastic modulus, elongation at break and hardness have been followed up as a function of irradiation dose and degree of loading with rubber content. Furthermore, the influence of radiation dose in the thermal parameters, melting temperature, heat of fusion, ΔHf of the recycled PA and its blend with waste rubber powder (WRP) was also investigated.

The effect of physical treatments of waste rubber powder on the mechanical properties of the revulcanizate

AbstractThe diversiform physical treatment processes of waste rubber powder were carried out using grinding process, ozone treatment, and ultrasonic treatment. The effects of these processes on hardness, specific gravity, crosslink, tensile strength, elongation, and dynamic mechanical properties were studied. Also, the morphology and the chain structure changing of waste rubber powder were studied by SEM and XPS, respectively. The ozone/ultrasonic treatment was found to be the most effective treatment to improve the mechanical properties of waste rubber powder revulcanizate. The effect of mechanism may be due to the sulfur crosslinkage network changed to a cyclic form. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009