Properties of styrene butadiene rubber (SBR)/recycled acrylonitrile butadiene rubber (NBRr) blends: The effects of carbon black/silica (CB/Sil) hybrid filler and silane coupling agent,Si69

The recycling or reuse of waste rubber by means of blending together with polymeric materials in addition of filler such as hybrid carbon black and silica (CB/Sil) to a polymer system can provides an opportunity to explore alternative product specifications. Therefore, in this work the investigation of recycled rubber blends based on styrene butadiene rubber/recycled acrylonitrile butadiene rubber (SBR/NBRr) blends reinforced with 50/0, 40/10, 30/20, 20/30, 40/10, 0/50 phr of carbon black/silica (CB/Sil) hybrid filler treated with and without silane coupling agent (Si69) were determined. Cure characteristics, tensile properties, and morphological behavior of selected SBR/NBRr blends at a fix 85/15 blend ratio were evaluated. Results showed that, cure time t₉₀, minimum torque (M_L), and maximum torque (M_H) of CB/Sil hybrid fillers filled SBR/NBRr blends with and without Si69 increased as silica content increased. However, t₉₀ and M_L of SBR/NBRr blends with Si69 were lower than without Si69 except for (M_H). The optimum scorch time (t_s2) of SBR/NBRr blends with and without Si69 was obtained at 30/20 phr of CB/Sil hybrid filler. However, t_s2 of SBR/NBRr blends with Si69 were longer than SBR/NBRr blends without Si69. The incorporation of Si69 has improved the tensile properties [(tensile strength, elongation at break (E_b), stress at 100% elongation (M100), and stress at 300% elongation (M300)] of CB/Sil hybrid fillers filled SBR/NBRr blends. These properties were influenced by the degree of crosslinked density as the silica content is increased. Scanning electron microscopy (SEM) of the tensile fracture surfaces indicated that, with the addition of Si69 improved the dispersion of hybrid fillers and NBRr in SBR/NBRr matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Curing Characteristics and Mechanical and Morphological Properties of Styrene Butadiene Rubber/Virgin Acrylonitrile-Butadiene Rubber (SBR/vNBR) and Styrene Butadiene Rubber/Recycled Acrylonitrile-Butadiene Rubber (SBR/rNBR) Blends

Curing characteristics and mechanical and morphological properties of styrene butadiene rubber/virgin acrylonitrile-butadiene rubber (SBR/vNBR) and styrene butadiene rubber/recycled acrylonitrile-butadiene rubber (SBR/rNBR) were investigated. Results indicated that the curing characteristics, such as scorch time, t₂, and cure time, t₉₀, of SBR/vNBR and SBR/rNBR blends decreased with increasing vNBR and rNBR content. At similar blend ratios, particularly up to 15 phr, SBR/rNBR blends exhibited higher t₂ and t₉₀ compared with SBR/vNBR blends. Minimum torque (ML) and maximum torque (MH) of SBR/vNBR blends significantly increased with increasing vNBR content. For SBR/rNBR blends, ML increased with increasing rNBR content, but MH exhibited the opposite trend. Tensile strength, elongation at break (E_b), resilience, and fatigue decreased with increasing virgin and recycled NBR content in both blends. Up to 15 phr, the tensile strength, E_b and fatigue life (Kc) of SBR/rNBR blends were higher than in SBR/vNBR blends. The M100 (stress at 100% elongation), hardness, and cross-linking density of both blends also showed an increasing trend with increasing vNBR and rNBR content. The scanning electron microscopy study indicates that rNBR exhibited a weak rNBR-SBR matrix interaction particularly when more than 15 phr of rNBR was used, thus decreasing the mechanical properties of SBR/rNBR blends.     

A Study of FTIR,Thermal Properties and Natural Weathering Test on NBRVirgin/Recycled with SBR Blends

The effects of styrene butadiene rubber/virgin acrylonitrile butadiene rubber (SBR/NBRv) blends and styrene butadiene rubber/recycled acrylonitrile butadiene rubber (SBR/NBRr) blends on properties such Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) were carried out. Results indicated that, based on intensity of amine peak from FTIR at 85/15 blend ratio (R15) revealed optimum formation of crosslink between SBR and NBR either using virgin or NBRr. TG thermograms of SBR/NBRv blends of all ratios showed better onset thermal stability than SBR/NBRr blends. The change in the horizontal baseline from high to low energy level occurred in virgin NBR blends because the amount of reactive sites available in virgin NBR is higher compared to NBRr. Meanwhile NBRr blends showed T_c because the amount of crosslink occurred in these blends were slightly lower than NBRv blends. Up to 25 phr of NBRr, the tensile strength and elongation at break (E_b) retention of SBR/NBRv blends was better than SBR/NBRr blends after 6 months' weathering test except for M100. The scanning electron microscopy on the surface of both blends after 6 months exposure indicated that the severity of the crack was minimal for SBR/NBRr blends compared to SBR/NBRv particularly at 50/50 blend ratio designated the SBR/NBRr blends that contained more NBRr particles could reduce the degradation towards natural weathering.     

Comparison of Properties of Polypropylene (PP)/Virgin Acrylonitrile Butadiene Rubber (NBRv) and Polypropylene (PP)/Recycled Acrylonitrile Butadiene Rubber (NBRr) Blends

The comparison properties of polypropylene (PP)/recycled acrylonitrile butadiene rubber (NBRr) blends and polypropylene/virgin acrylonitrile butadiene rubber (NBRv) blends were investigated. The tensile properties such as tensile strength, tensile modulus and elongation at break of PP/NBRv blends are higher than PP/NBRr blends. However, PP/NBRv blends exhibit lower stabilization torque and higher swelling percentage than PP/NBRr blends. Based on SEM, a finer morphology was observed in PP/NBRv blends in comparison with the PP/NBRr blends. The thermal stability of PP/NBRr is better than that of PP/NBRv blends.     

Natural Weathering Test of Styrene Butadiene Rubber and Recycled Acrylonitrile Butadiene Rubber (SBR/NBRr) Blends

The effect of recycled acrylonitrile butadiene rubber (NBRr) content of SBR/NBRr blends on natural weathering was studied. Three different size of NBRr (S1; 117–334 µm, S2; 0.85–15.0 mm and S3; direct sheeted form) were used and the blends were exposed to natural weathering for 3 and 6 months. The results indicated that the SBR/NBRr blends with smallest size of NBRr (S1) show a better retention of tensile properties, which are able to withstand better weathering than coarser size (S2 and S3) of SBR/NBRr blends. The presence of hydroxyl, carbonyl and nitro group after exposure to natural weathering was detected in FTIR analysis, which related to the UV oxidation process of rubber blends. The scanning electron microscopy proved that the SBR/NBRr blends with smallest size of NBRr (S1) with higher content of NBRr, shows a better resistant to natural weathering.     

Comparison Properties of Natural Rubber (SMR L)/Ethylene Vinyl Acetate (EVA) Copolymer Blends and Epoxidized Natural Rubber (ENR-50)/Ethylene Vinyl Acetate (EVA) Copolymer Blends

Mixing torque, morphology, tensile properties and swelling studies of natural rubber/ethylene vinyl acetate copolymer blends were studied. Two series of unvulcanized blends, natural rubber/ethylene vinyl acetate (SMRL/EVA) copolymer blend and epoxidized natural rubber (50% epoxidation)/ethylene vinyl acetate (ENR-50/EVA) copolymer blend were prepared. Blends were prepared using a laboratory internal mixer, Haake Rheomix polydrive with rotor speed of 50 rpm at 120°C. Results indicated that mixing torque value and stabilization torque value in ENR-50 blends are lower than SMRL blends. The process efficiency of ENR-50/EVA blends is better due to less viscous nature of the blend compared to SMRL/EVA blends as indicated in stabilization torque graph. Tensile properties like tensile strength, M100 (modulus at 100% elongation) and E _b (elongation at break) increase with increasing EVA fraction in the blend. At the similar blend composition, ENR-50 blend shows better tensile properties than SMRL blends. In oil resistance test, swelling percentage increased with immersion time and rubber composition. At a similar immersion time, ENR-50 blends exhibit better oil resistance compared to SMRL blends. Scanning electron microscopy (SEM) of tensile fractured surface indicated that EVA/ENR-50 blends need higher energy to cause catastrophic failure compared to EVA/SMRL blends. In etched cryogenically fractured surface, size and distribution of holes due to extraction of rubber phase by methyl ethyl ketone (MEK) were studied and holes became bigger as rubber composition increased due to coalescence of rubber particle.     

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

The 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     

Properties of Polypropylene (PP)/Ethylene-Propylene Diene Terpolymer (EPDM)/Natural Rubber (NR) Vulcanized Blends: The Effect of N,N-m-Phenylenebismaleimide (HVA-2) Addition

This paper discusses process development, tensile properties, morphology, oil resistance, gel content, and thermal properties of polypropylene (PP)/ethylene-propylene diene terpolymer (EPDM)/natural rubber (NR) vulcanized blends with the addition of N,N-m-phenylenebismaleimide (HVA-2) as a compatibilizer. Blends were prepared in several blend ratios in a Haake Polydrive with temperature and rotor speed of 180°C and 50 rpm, respectively. Results indicated that the combination of dicumyl peroxide (Dicup) with HVA-2 shows high torque development and stabilization torque as compared to the blend with Dicup vulcanization alone. In terms of tensile properties, the combination of Dicup with HVA-2 shows higher tensile strength, tensile modulus (M₁₀₀), elongation at break, oil resistance, and gel content in all blend ratios compared to similar vulcanized blends with Dicup without HVA-2 addition. Scanning electron microscope (SEM) micrographs of the blends support that the cross-linking and compatibilization occur during the process of the vulcanized blend containing HVA-2. In the case of crystallinity of the blends, the addition of HVA-2 in Dicup vulcanized blend revealed a tendency for the percentage of crystallinity (Xc) to decrease. The addition of HVA-2 in Dicup vulcanization also produced blends with good thermal stability dealing with the so-called coagent bridge formation.     

Electrical and Mechanical Properties of Some Butadiene Rubber Composites in the Vicinity of the Percolation Threshold

The electrical and mechanical properties of NBR/SBR blends with different compositions were studied before the addition of carbon black. The increase in permittivity ε′ and dielectric loss ε″ noticed by increasing NBR content is due to the increase in C ≡ N dipoles. The mechanical properties which include tensile and elongation at yield and rupture are also found to be increased. This work also includes the compatibility study, which was carried out using different tools and techniques (Heat of mixing, dielectric and scanning electron microscope). This study led to a conclusion that both blends are incompatible.

The electrical as well as the mechanical properties were carried out on NBR, SBR and NBR/SBR blend (50/50) to be loaded with different concentrations of high abrasion furnace black (HAF) in order to find out the percolation thresholds in relation to the net work formation.

The electrical conductivity of carbon-black-filled composites is increased from pure polymer to that of pure carbon, through the change in the different composites. Up till certain concentration of HAF (30 phr for both NBR and SBR) and 20 phr for NBR/SBR blends the conductivities of the composites are approximately the same and closed to that of the pure, electrically insulating polymer matrix. These concentrations are called percolation thresholds. Above such concentrations, the conductivity increases many orders of magnitude with very little increase in the filler amount. With this increase the tendency of conductivity chain formation increases through the aggregation of the carbon black particles network. The change in conductivity beyond the percolation threshold is expressed according to the percolation theory with straight line when plotted graphically versus P-P_c; P_c is the volume fraction of carbon black at the percolation threshold.

In addition to the conductivity term, the data of permittivity ε′ and dielectric loss ε″ given at different frequencies from 100 Hz up to 100 kHz show an abrupt increase at 30 phr HAF for NBR & SBR and 20 phr HAF for NBR/SBR. More over, the relaxation times obtained from the analyses of these data using Fröhlich and Havriliak-Nagami functions, which ascribe the orientation of the large aggregates caused by the movement of the main chain also show an abrupt increase at the same concentration of HAF.

The mechanical properties, which investigated through the measurements of tensile and elongation at yield and rupture indicate an abrupt increase at the same concentration of HAF found in the case of electrical measurements. This result gives evidence to the good applicability between both mechanical and electrical investigations through the network formations.

Any how, the percolation threshold found in case of NBR/SBR blend is less than that for NBR itself. This result is attributed to the uneven distribution of the filler in the incompatible blend matrix.     

The Effect of Dynamic Vulcanization on the Properties of Polypropylene/Ethylene-Propylene Diene Terpolymer/Natural Rubber (PP/EPDM/NR) Ternary Blend

The effects of dynamic vulcanization on the process development and some properties, such as tensile properties, swelling index, gel content, crystallinity, and morphology, of the polypropylene (PP)/ethylene-propylene diene terpolymer (EPDM)/natural rubber (NR) blends were investigated. Dynamically vulcanized blends show higher stabilization torque than unvulcanized blends. In terms of tensile properties, the tensile strength and tensile modulus (stress at 100% elongation, M₁₀₀) of the vulcanized blends have been found to increase as compared with the unvulcanized blends, whereas the elongation at break is higher in the blend with richer EPDM content. These results can be attributed to the formation of cross-linking in the rubber phase. The formation of cross-links in the rubber phase has also been proved by swelling index and gel content. The percentage of crystallinity of the blends is decreased by dynamic vulcanization. Scanning electron microscopy (SEM) micrographs from the surface extraction of the blends support that the cross-links occurred during dynamic vulcanization.     

Effect of crosslinking monomers on the performance of electron beam-induced biodegradable Bionolle–rubber blends

To find out the better crosslinking monomer for vulcanization of natural rubber under electron beam (EB) radiation, the dry rubber was masticated with different polyfunctional monomers like TMPTA, NVP, and ethylene glycol diacrylate of different numbers of CH₂ CH₂ O group, such as 1G, 3G, 7G, and 10 G. The masticated films were irradiated with different doses under EB at 10 kGy/pass. The highest tensile strength (25 MPa) of the rubber was observed in the presence of TMPTA (3phr) at 150 kGy dose. The gel content of the rubber increased with an increase of dose. Bionolle was mixed with the masticated rubber containing 3 phr TMPTA at different proportions; films of these blends along with Bionolle were irradiated under EB with different doses. The concentration of rubber in Bionolle and radiation dose were optimized. The elastomer with 5% masticated showed the highest tensile strength (62 MPa). The gel content of the blends was found to increase with an increase of radiation dose as well as rubber concentration in Bionolle. The elastomers or blends were found to possess good thermal properties. The elastomers exhibited a much lower loss of tensile strength due to the thermal aging compared with pure Bionolle. The elastomers sustained their original shape for 300 min at 180°C, whereas Bionolle sustained its shape for only 3 min at 120°C under the same load (50 g). Among all the elastomers, 5% rubber containing elastomer was found to be better in all respects. It was observed from scanning electron microscopy and differential scanning calorimetry studies that 5% rubber is well mixed with Bionolle. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 799–807, 2001     

Vinyl acetate content and electron beam irradiation directed alteration of structure,morphology, and associated properties of EVA/EPDM blends

A series of ethylene vinyl acetate/ethylene–propylene diene elastomer (EVA/EPDM) blends with four types of EVAs with various vinyl acetate (VA) content, are prepared without and with crosslinker, trimethylol propane triacrylate (TMPTA). These are irradiated by electron beam (EB). As the VA content increases, the gel content, i.e., degree of crosslinking of EVA/EPDM blends, is increased. With increase in VA content, the modulus and tensile strength are decreased but elongation at break is increased due to increase in amorphousness. On EB irradiation, modulus and tensile strengths are increased but at the cost of elongation at break. Crystallinities of all blends are decreased with increase in VA and EB crosslinking. The thermal stability of EVA/EPDM blend is decreased with increase in VA content but increased after EB irradiation. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) show that with increase in VA content the miscibility of two polymers keeps on increasing, which even become more after EB irradiation. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43468.     

Electron‐beam irradiation of blends of polypropylene with recycled acrylonitrile‐butadiene rubber

One‐mm thick sheets were prepared from blends of polypropylene and recycled acrylonitrile‐butadiene rubber (rNBR) with different blend ratios. Trimethylolpropane triacrylate (TMPTA) was used as a co‐agent. Electron‐beam‐initiated cross‐linking of the sheets was carried out at a dose of 40 kGy, and 3 phr of TMPTA based on the weight of rNBR was used. Properties such as tensile strength, Young's modulus, elongation at break, swelling percentage in oil, and morphology were studied. The results showed that the tensile properties had been improved by irradiation. The studies of swelling in oil revealed a higher cross‐link density in the irradiated blends compared to that in nonirradiated blends at similar blend ratios. Scanning electron microscopy studies revealed better adhesion between the phases and rough failure surfaces with a large number of tear lines which indicated a higher energy requirement for the failure of irradiated blends compared to that for nonirradiated blends. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers     

Influence of Particle Type and Silane Coupling Agent on Properties of Particle-Reinforced Styrene-Butadiene Rubber

Silica- and carbon-filled styrene butadiene rubber (SBR) were prepared. The influence of particle type and silane coupling agent on cure characteristics, physical and dynamic mechanical properties of particle-reinforced SBR were investigated. Minimum torque, maximum torque and tensile strength increased with increase of the filler content. The tensile strength and elongation at break were highest for presence of bis-(3-triethoxysilylpropyl) tetrasulfide (TESPT) in silica-filled vulcanizates. The dynamic mechanical properties show that tan δ at temperatures of ?20–0°C of the SiO₂/TESPT/SBR vulcanizate was highest of all. Tan δ at temperatures of 50–70°C of the SiO₂/TESPT/SBR vulcanizate was lower than carbon-filled SBR.     

The effect of irradiation on morphology and properties of the PET/HDPE blends with trimethylol propane trimethacrylate (TMPTA)

The mechanical properties of poly(ethylene terephthalate)/high-density poly(ethylene) (PET/HDPE) blends were improved by γ-ray irradiation combined with using a cross-linking agent—trimethylol propane trimethacrylate (TMPTA). The effect of the weight ratio of PET/HDPE, the content of TMPTA and the absorbed dose on the phase morphology and the mechanical properties of the PET/HDPE blends were investigated through scanning electron microscopy (SEM), gel fraction, Fourier transform infrared spectroscopy (FTIR), tensile and impact tests. SEM images showed that the phase structure changed significantly as TMPTA coexistence. The results of tensile and impact tests indicated that their mechanical properties depended on their structures. FTIR spectra suggested that a new structure of HDPE-g-PET was generated. When the weight ratio of PET/HDPE blend was 80/20, the content of TMPTA was 1 wt% and the absorbed dose was 30 kGy, the tensile strength, elongation at break and impact strength of irradiated blends were improved greatly compared with non-irradiated blends.     

Effect of filler loading on cure time and swelling behaviour of SMR L/ENR 25 and SMR L/SBR blends

The effect of filler loading on the cure time (t₉₀) and swelling behaviour of SMR L/ENR 25 and SMR L/SBR blends has been studied. Carbon black (N330), silica (Vulcasil C) and calcium carbonate were used as fillers and the loading range was from 0 to 40 phr. Results show that for SMR L/ENR 25 blends the cure time decreases with increasing carbon black loading, whereas silica shows an increasing trend, and calcium carbonate does not show significant changes. For SMR L/SBR blends, the cure time of carbon black, silica and calcium carbonate generally decreases with increasing filler loading. The percentage swelling in toluene and ASTM oil no 3 decreases for both blends with increasing filler loading, with calcium carbonate giving the highest value, followed by silica‐ and carbon black‐filled blends. At a fixed filler loading, SMR L/ENR 25 blend shows a lower percentage swelling than SMR L/SBR blends. © 2003 Society of Chemical Industry     

Curing Characteristics,Mechanical and Morphological Properties of Kenaf Fibre/Halloysite Nanotubes Hybrid-Filled Natural Rubber Compounds

Natural rubber compounds were prepared with different kenaf/HNT ratio loading i.e., 30/0, 20/10, 15/15, 10/20, 0/30 (phr/phr). The compounds were cured at 150°C according to its t₉₀. Curing characteristic, tensile properties, fatigue, rubber-filler interaction and morphological properties of the compounds were tested. Curing characteristics show that scorch time and cure time increased with increasing of HNT ratio loading while minimum and maximum torque decreased. When HNT ratio loading was increased, tensile strength and elongation at break and fatigue life increased while tensile modulus decreased. Swelling measurement and morphological study showed that better rubber-filler interaction was obtained with higher HNT ratio loading.     

Swelling and mechanical properties of (acrylonitrile‐butadiene rubber)/(hydrogenated acrylonitrile‐butadiene rubber) blends with precipitated silica filled in gasohol fuels

This work studied the effects of hydrogenated acrylonitrile‐butadiene rubber (HNBR) and precipitated silica (PSi) loadings in acrylonitrile‐butadiene rubber (NBR) filled with 60 parts per hundred of rubber (phr) of carbon black (CB) for oil‐resistant seal applications in contact with gasohol fuel. The cure characteristics, mechanical properties, and swelling behavior of HNBR/NBR blends reinforced with PSi before and after immersion in ethanol‐based oils (E10, E20, and E85) were then monitored. This work studied the effects of PSi loading in rubber compounds on the mechanical properties of the rubber blends. The results suggested that the scorch time of CB‐filled NBR/HNBR was not affected by HNBR loading, but the cure time, Mooney viscosity, and torque difference increased with HNBR content. The swelling of the blends in E85 oil were relatively low compared with those in E10 and E20 oils. The recommended NBR/HNBR blend ratio for oil‐resistant applications was 50/50. Tensile strength and elongation at break before and after immersion in gasohol oils increased with HNBR loading, and the opposite effect was found for tensile modulus and hardness. PSi filler had no effect on scorch time, but decreased the cure time of the blends. The swelling level of the blends slightly decreased with increasing PSi content. The recommended silica content for optimum reinforcement for black‐filled NBR/HNBR blend at 50/50 was 30 phr. The results in this work suggested that NBR/HNBR blends reinforced with 60 phr of CB and 30 phr of silica could be potentially used for rubber seals in contact with gasohol fuels. J. VINYL ADDIT. TECHNOL., 22:239–246, 2016. © 2014 Society of Plastics Engineers     

Compatibilization of SBR/NBR Blends Using Poly Acrylonitrile as Compatibilizer

Blends of styrene-co-butadiene rubber (SBR) and acrylonitrile-co-butadiene rubber (NBR) were prepared and their rheological and mechanical properties were examined. The effect of the addition of 5 phr of poly acrylonitrile as compatibilizer on the compatibility of the rubber blend was studied. Ultrasonic and scanning electron microscopy (SEM) techniques were used to assess the degree of compatibility of the blend. The results revealed that the use of the prepared compatibilizer has significantly resulted in the clear stability of the cure rate index (CRI) of the blends and that the tensile strength was improved at (50/50) SBR/NBR blend. The degree of compatibility was enhanced to a great extent.     

Effect of Carbon Black/Silica Hybrid Filler on Thermal Properties,Fatigue Life,and Natural Weathering of SBR/Recycled NBR Blends

The utilization of nitrile glove waste will spark a great deal of interest in the rubber industry in developing cost-effective techniques to convert waste and used rubber into a processable form. Blends of styrene butadiene rubber/recycled acrylonitrile butadiene rubber (SBR/NBRr) reinforced at 85/15 blend with different ratios of a carbon black/silica (CB/Sil) hybrid filler (50/0, 40/10, 30/20, 20/30, 40/10, 0/50 phr) were tested either with or without the silane coupling agent, Si69. Results showed that the increased thermal stability of blends with Si69 is highly related to the formation of crosslinks between the filler. Thermogravimetric (TG) thermograms showed that the percentage of char residue for blends with Si69 was higher than without Si69. The differential scanning calorimetry (DSC) thermograms of both blends revealed a glass transition temperature (Tg) between 65.0°C and 66.9°C. At all blend ratios, the fatigue life of blends with Si69 was better than blends without Si69. After six months’ exposure to natural weather, blends with Si69 exhibited better tensile properties, retention, and morphology compared to blends without Si69.