Styrene Butadiene Rubber Blends Research Articles

Intelligent Modelling of the Real Dynamic Viscosity of Rubber Blends Using Parallel Computing.

Modelling the flow properties of rubber blends makes it possible to predict their rheological behaviour during the processing and production of rubber-based products. As the nonlinear nature of such complex processes complicates the creation of exact analytical models, it is appropriate to use artificial intelligence tools in this modelling. The present study was implemented to develop a highly efficient artificial neural network model, optimised using a novel training algorithm with fast parallel computing to predict the results of rheological tests of rubber blends performed under different conditions. A series of 120 real dynamic viscosity-time curves, acquired by a rubber process analyser for styrene-butadiene rubber blends with varying carbon black contents vulcanised at different temperatures, were analysed using a Generalised Regression Neural Network. The model was optimised by limiting the fitting error of the training dataset to a pre-specified value of less than 1%. All repeated calculations were made via parallel computing with multiple computer cores, which significantly reduces the total computation time. An excellent agreement between the predicted and measured generalisation data was found, with an error of less than 4.7%, confirming the high generalisation performance of the newly developed model.

Triple Silicon, Phosphorous, and Nitrogen-Grafted Lignin-Based Flame Retardant and Its Vulcanization Promotion for Styrene Butadiene Rubber.

In this study, we present an innovative environmental silicon-, phosphorus-, and nitrogen-triple lignin-based flame retardant (Lig-K-DOPO). Lig-K-DOPO was successfully prepared by condensation of lignin with flame retardant intermediate DOPO-KH550 synthesized via Atherton-Todd reaction between 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and γ-aminopropyl triethoxysilane (KH550A). The presence of silicon, phosphate, and nitrogen groups was characterized by FTIR, XPS, and 31P NMR spectroscopy. Lig-K-DOPO exhibited advanced thermal stability compared with pristine lignin supported by TGA analysis. The curing characteristic measurement showed that addition of Lig-K-DOPO promoted the curing rate and crosslink density to styrene butadiene rubber (SBR). Moreover, the cone calorimetry results indicated Lig-K-DOPO conferred impressive flame retardancy and smoke suppression. The addition of 20 phr Lig-K-DOPO reduced SBR blends 19.1% peak heat release rate (PHRR), 13.2% total heat release (THR), 53.2% smoke production rate (SPR), and 45.7% peak smoke production rate (PSPR). This strategy provides insights into multifunctional additives and greatly extends the comprehensive utilization of industrial lignin.

Multifunctional poly(vinylidene fluoride) and styrene butadiene rubber blend magneto-responsive nanocomposites based on hybrid graphene oxide and Fe3O4: synthesis, preparation and characterization

Two materials were used, like graphene oxide nanosheets (GOn) and ferromagnetic nanoparticles (Fe3O4), to attenuate the electromagnetic (EM) properties in blend hybrid nanocomposites based on styrene-butadiene rubber (SBR) and polyvinylidene difluoride (PVDF) as the matrix. The rationale behind using either a ferroelectric or a ferromagnetic nanofillers as Fe3O4 in combination with intrinsically conducting nanofillers (graphene oxide) at different weight ratios (3.75:1.25; 2.5:2.5 and 1.25:3.75), is to induce both electrical and magnetic dipoles in the hybrid nanocomposite system and characterization to determine the effect of nanofillers hybridization in improving the structural, mechanical, dielectric/electrical, magnetic and thermal properties of a polymer blend (PVDF-SBR) for electromagnetic interference (EMI) shielding application. Due to the synergy between both nanofillers, it was found that Young’s modulus of the nanocomposite containing 5 wt% of the hybrid nanofiller was significantly improved (87%), while the strain at yield remained constant due to the low particle content and the rubbery effect of the SBR copolymer. In addition, the degradation temperature of the matrix was shifted from 464 to 472 °C with the addition of 2.5:2.5 of GOn:Fe3O4. Finally, the hybrid reinforcement also had a positive effect on the electrical and magnetic properties of the nanocomposites with an improvement that exceeds 30%. By careful selection of synthetic techniques and understanding/exploiting the unique physics of the polymeric nanocomposites in such materials, novel functional polymer-inorganic nanocomposites can be designed and fabricated for new interests in magneto applications such as superparamagnetism, electromagnetic wave absorption, and electromagnetic interference shielding. This study opens new avenues to design flexible and lightweight electromagnetic interference shielding materials by careful selection of functional nanoparticles.

An Investigation on the Thermally Induced Compatibilization of SBR and α-Methylstyrene/Styrene Resin.

The miscibility between two polymers such as rubbers and performance resins is crucial to achieve given targeted properties in terms of tire performances. To this aim, α-methylstyrene/styrene resin (poly(αMSt-co-St)) are used to modify the viscoelastic behavior of rubbers and to fulfill the requirements of the final applications. The initial aim of this work was to understand the influence of poly(αMSt-co-St) resins blended at different concentrations in a commercial styrene-butadiene rubber (SBR). Interestingly, while studying the viscoelastic properties of SBR blends with poly(αMSt-co-St), crosslinking of the rubber was observed under conditions where it was not expected to happen. Surprisingly, after the crosslinking reactions, the poly(αMSt-co-St) resin was irreversibly miscible with SBR at concentrations far above its immiscibility threshold. A detailed investigation involving characterization technics including solid state nuclear magnetic resonance led to the conclusion that poly(αMSt-co-St) is depolymerizing under heating and can graft onto the chains of SBR. It results in an irreversible compatibilization mechanism between the rubber and the resin.

Investigation of an insulating waste conscious material for sustainable building application

One of the risks that threaten future generations is depletion of resources. Therefore, the exploitation of waste is one of the most successful ways to preserve resources and produce multi-use building materials. Calcium carbonate (CaCO3)/ Natural Rubber / Styrene-butadiene Rubber blend (NR/SBR) and (CaCO3)/foamed NR/SBR rubber blend were prepared by mastication -vulcanization technique. Specific gravity for all samples were determined while ranged between (0.42-1.4) for (CaCO3)/foamed rubber blend and between (1.003 – 2.9) for unfoamed rubber blend. Scanning electron microscope (SEM) for samples 150 phr of foamed and unfoamed rubber was done to compare the types of matrices. Thermal conductivity of the two groups were measured. The samples with concentrations till 150 phr CaCO3 foamed rubber lies in the range of thermal insulating materials while the samples of unfoamed rubber have higher thermal conductivity values. Water absorption test was conducted. The water absorption coefficient values of the foamed rubber are lower than that of unfoamed rubber. Mechanical measurements and swelling properties were investigated for all samples. The sample with 150 phr foamed rubber blend considered the optimum sample that achieve all desired thermal and moisture insulating properties.

Mechanical behavior of silicon carbide filled SBR/NBR blends

Generally, SBR and NBR are widely used in industrial as well as in automobile applications. The main aim of this research is to determine the mechanical properties and their behavior of SBR (Styrene Butadiene Rubber) and NBR (Nitrile Butadiene Rubber) blends mixed with silicon carbide (SiC – as filler) in different compositions. SBR and NBR sheets, and SiC powder are bought and the rubbers are mixed to form blends in order to enhance the properties. Mechanical properties such as tensile, tear, abrasion and resilience tests were conducted according to ASTM standards. Also, hardness was also measured, and properties of all samples were compared. Graphs were drawn to compare the results obtained. Enhancement in properties were obtained and noted.

Material identification for improving the strength of silica/SBR interface using MD simulations.

Comprehensive molecular dynamics simulations are conducted to identify material modifications which can improve strength and reduce hysteresis losses at the nanointerfaces formed between silica, silane coupling agent (SCA) and styrene-butadiene rubber (SBR), all of which are important ingredients of green tyres. Improving strength and reducing hysteresis losses at such interfaces are expected to reduce rolling resistance (RR), consequently lowering greenhouse emissions. Various modifications considered in this work include a variety of SBR blends, several SCA and surface occupancies of SCA on the silica surface. To tackle a large number of combinations possible and identify modifications which may improve the nature of the interfaces, a hierarchical computational framework is developed. The reduced sample space of such material modifications may be more amenable to comprehensive and computationally or experimentally expensive studies. It was found that some amino-based SCA in combination with certain blends of SBR can improve the interfaces strength and lower hysteresis losses, when compared to the commonly used bis[3-(triethoxysilyl)propyl]tetrasulfide (TESPT), which is a sulphur-based SCA.

Oil from tyre pyrolysis as a plasticizer in rubber compounds

The paper presents the results of research on the possibility of using as plasticizers of rubber compounds the heavy fractions of pyrolytic oil obtained in the industrial process of pyrolysis of car tyres. The content of carcinogenic polycyclic aromatic hydrocarbons (PAHs) in the obtained pyrolytic plasticizers was determined. Compounds and vulcanizates of styrene-butadiene rubber (SBR) containing the above plasticizers as well as commercial petroleum derivatives’ plasticizers were prepared for comparative purposes. The basic properties of compounds and vulcanizates containing pyrolytic plasticizers were investigated. The research showed that one fraction of pyrolysis oil meet the requirements of the permitted content of PAHs. SBR blends and vulcanizates have similar properties as in the case of commercial plasticizers.

실리카 및 카본블랙이 보강된 ENR/SSBR 블렌드의 물성 연구

에폭시화 천연고무(ENR)와 솔루션-스디렌-부다디엔 고무(SSBR)를 150:50로 혼합한 고무 블렌드를 실리카 및 카본블랙을 충전제로 보강하였다. 제조된 고무 복합체의 물성은 고무 가공 분석기로 측정되었고, 형태학적 구조는 SEM으로 확인되었다. 열무게 분석, 인장강도, 경도, 마찰계수 및 발반탄성은 ENR/SSBR 블렌드의 물성을 확인하기 위하여 조사되었다. 모든 실험 결과에서, 복합체의 내열성, 경도, 인장강도 및 충전제의 분산성은 실리카 함량이 증가함에 따라 향상되었음을 알 수 있었다. 그 원인은 실리카와 ENR부분 사이에 수소 결합이라는 더 나은 결합의 형성이었다. 또한 블렌드의 마찰계수과 발반탄성은 카본블랙 함량이 증가함에 따라 향상되었다. 그 원인은 카본블랙과 블렌드의 결합효과(coupling effect) 및 윤활성이 개선됨에 기인함을 알았다.

Styrene Butadiene Rubber/Silicone Rubber Blends Filled With Dough Moulding Compound

Blends of styrene butadiene rubber (SBR)/methyl-vinyl silicone rubber (MVQ) filled with dough molding compound (DMC) were prepared and the effects of various amounts of the SBR, as a compatibilizer of MVQ and DMC, on the mechanical properties and the oxygen index of the DMC filled SBR/MVQ blends were investigated. Dynamic mechanical analysis (DMA) and infrared spectrum analysis (IR) of the DMC/SBR/MVQ blends were also investigated. The results showed that the mechanical properties of the DMC filled MVQ blends were improved when SBR was used as a compatibilizer; the best mass ratio was 60 phr (parts per hundred total rubber) DMC, 25 phr SBR and 75 phr MVQ. The volume electric resistivities of the DMC filled SBR/MVQ blends with various DMC mass ratios were all above 5.8 × 1012 Ω•m; i.e., the electrical insulating property of the blends was excellent. Compared with the blends without DMC and the blends without SBR, the energy storage modulus and the peak area of the loss factor tan δ of the DMC reinforced SBR/MVQ blends were largest; the addition of DMC and SBR improved the thermal properties of the blends.

Structural, Dynamic Mechanical, Mechanical and Thermal Analysis of Cis-Polyisoprene and Styrene-Butadiene Rubber Blends

Structural, Dynamic Mechanical, Mechanical and Thermal Analysis of Cis-Polyisoprene and Styrene-Butadiene Rubber Blends

Innovative neutron shielding materials composed of natural rubber-styrene butadiene rubber blends, boron oxide and iron(III) oxide

Optimized flexible and lightweight neutron shielding materials were designed using the Monte Carlo N-Particle (MCNP) code. Thicknesses of 10 mm and 100 mm were tested for neutron shielding performances. Simulation results indicated that the 10 mm shielding material of natural rubber (NR) and styrene butadiene rubber (SBR) blend (1:1) with 60 part per hundred rubber (phr) boron oxide (B2O3) and 100 mm shielding material with four alternating layers of NR with 100 phr iron (III) oxide (Fe2O3) and of NR and SBR blend (1:1) with 10 phr B2O3 were most suitable for thermal neutron shielding and all-energy neutron shielding, respectively. Experimental results verified the shielding efficiency of these optimal designs and ease of fabrication.

Thermomechanical reclaiming of ground tire rubber via extrusion at low temperature: Efficiency and limits

Thermomechanical reclaiming of ground tire rubber (GTR) was performed at different temperatures (60, 120, and 180°C) using a co‐rotating twin‐screw extruder. Obtained samples were used in styrene‐butadiene rubber (SBR) blends. As reference samples, SBR compounds containing untreated GTR were used. Curing characteristics, static and dynamic mechanical properties, and morphology of the obtained blends were determined. The results show that the increase of barrel temperature during the thermomechanical reclaiming of GTR has a positive effect on the decrease of screw torque (lower machine load) and decrease of Mooney viscosity (better processing characteristics). However, mechanical properties and crosslink density of rubber revulcanizate decreased with increasing barrel temperature during the reclaiming process. SBR blends with 50 phr of reclaimed rubber showed increasing phase compatibility between SBR matrix and the reclaimed rubber, which was confirmed by mechanical properties and morphology measurements. J. VINYL ADDIT. TECHNOL., 22:213–221, 2016. © 2014 Society of Plastics Engineers

High strain extensional rheometry of polymer melts: Revisiting and improving the Meissner design

A new extensional rheometer limited in achievable strain only by sample rupture is presented. The rheometer is based on the Meissner design of two pairs of counter-rotating rollers pulling a sample of fixed length but is small enough to fit inside the oven of a standard rotational rheometer and thus is dubbed the Meissner Extensional Rheometry Accessory (MERA). The true strain rate is calculated by visually accessing the sample during deformation using a high-speed digital camera. Extensional experiments were performed on three materials representing a wide range expected rheological behavior, a styrene-butadiene rubber blend, a linear polystyrene, and a branched low-density polyethylene. The MERA was able to accurately replicate the results of the well-known Sentmanat extensional rheometer (SER) design in terms of onset of strain-hardening and absolute transient extensional viscosity values. However, due to its design, it was possible to achieve homogeneous extensional flow up to real Hencky strains in excess of 8, which corresponds to a linear stretch in excess of 3000. By comparison, the SER is limited to one drum revolution, which corresponds to a Hencky strain of 3.5–4.0 or a maximum linear stretch of approximately 50. Previously the highest Hencky deformations reported in the literature are for the filament stretching extensional rheometer and Rheometric Scientific RME apparatus and in both cases approach 7, which corresponds to a linear stretch of approximately 1000.

The Effect of Epoxidized Natural Rubber and Two Kinds of Organoclay upon Molecular Interaction, Structure and Mechanical Properties of (Styrene-Butadiene Rubber/Acrylonitrile-Butadiene Rubber/Organoclay) Nanocomposites

Epoxidized natural rubber (ENR50) and two different kinds of organoclay (C30B and C15A) were used in blends of styrene-butadiene rubber (SBR) and acrylonitrile butadiene rubber (NBR) and their effects upon interaction between phases, morphology, and mechanical properties of the blends were investigated. The compounds were characterized by means of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), and differential scanning calorimetry (DSC). The obtained results showed formation of hydrogen bonding between the compounds ingredients due to incorporation of C30B, especially in presence of ENR. AFM and FE-SEM analysis revealed good dispersion of the nanoparticles in the polymer matrix upon addition of ENR as well as better dispersion of C30B than C15A in the NBR phase. XRD results showed a greater expansion of the silicate layers by simultaneous use of organoclay and ENR Incorporation of organoclay alone or in combination with ENR in the blends caused shifting of the SBR Tg toward the NBR Tg. The tensile properties of the blends showed improvement by using nanoparticles in the presence of ENR.

Preparation and characterization of natural rubber/ultrafine full-vulcanized powdered styrene–butadiene rubber blends

In this paper, natural rubber (NR)/ultrafine full-vulcanized styrene–butadiene powdered rubber (UFPSBR) blends were prepared and studied for the first time. Scanning electron microscopy and thermogravimetric analysis were employed to characterize UFPSBR. Equilibrium swelling method was used to determine the crosslink density of NR/UFPSBR vulcanizates. The results on mechanical properties showed that when NR/UFPSBR ratio was 100/5, the formulation exhibited favorable performances compared to pure NR vulcanizates. The heat build-up temperature also decreased after adding UFPSBR into the NR formulation. In dynamic mechanical analysis, in the temperature range of −10 to −5 °C, loss factor (tanδ) values of NR/UFPSBR vulcanizates showed an increasing trend over the given temperature range and exhibited a peak value at approximate −5 °C. This indicates that wet traction and rolling resistance of samples were improved after UFPSBR was added in NR. This research demonstrates that UFPSBR can be incorporated into a conventional NR formula to successfully improve the comprehensive performances and dynamic mechanical properties of NR formula.

Poly(N‐isopropylacrylamide)‐Modified Styrene‐Butadiene Rubber as Thermoresponsive Material

Narrowly distributed (N‐isopropylacrylamide) (NIPAM) polymers are prepared by reversible addition–fragmentation chain transfer (RAFT) polymerization. After successful cleavage of the trithiocarbonate end groups (thiol generation), they can be grafted to styrene‐butadiene rubber (SBR) by a radical thiol‐ene reaction leading to various grafted SBR‐copolymers. During the grafting reaction, no crosslinking or branching of the SBR can be observed. Measurements of the contact angle of water show that the lower critical solution temperature (LCST) properties of the PNIPAM fraction affect the SBR. Films of the graft‐copolymer exhibit a distinct hydrophilicity below the LCST, while they show hydrophobic behavior above the LCST. Rheological measurements reveal a physical crosslinking of the functionalized SBR due to nanophase separation of the PNIPAM chains (hard phase) in the unpolar SBR. Compared with blends of SBR and PNIPAM, the PNIPAM‐grafted SBR possesses a much finer distribution of the PNIPAM domains (10–30 nm) within the matrix. In addition, two novel difunctional chain‐transfer agents are used, leading to difunctional PNIPAM, enabling a covalent crosslinking of SBR. image

Thermal characterization of SBR/NBR blends reinforced with a mesoporous silica

AbstractIn this article, blends of styrene butadiene rubber (SBR) and acrylonitrile butadiene rubber (NBR) filled with a mesoporous silica are characterized by using scanning electron microscopy (SEM), dynamic mechanical analysis, and differential scanning calorimetry. According to the variation of the glass transition temperature with the composition of the blends, it is deduced that the compatibility of SBR and NBR is reduced in the presence of mesoporous silica. Analysis of the morphology of the composites by SEM shows that the dispersion of the filler is improved in the presence of NBR which is an indicative that this elastomer interacts stronger with silica than SBR. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Effect of gamma irradiation on the properties of natural rubber/styrene butadiene rubber blends

Blends of natural rubber (NR) with styrene butadiene rubber (SBR) with varying ratios have been prepared. Vulcanization of the prepared blends has been induced by irradiation of gamma rays with varying doses up to 250kGy. Mechanical properties, namely tensile strength, tensile modulus at 100% elongation, elongation at break have been followed up as a function of irradiation dose as well as blend composition. Physical properties, namely gel fraction and swelling number have been followed up using benzene as a solvent. Thermal measurements namely thermogravimetric analysis were carried out. The results indicated that the addition of NR has improved the properties of NR / SBR blends. Also NR/SBR blend is thermally stable than NR alone.

Dynamically vulcanized polypropylene/styrene–butadiene rubber blends: The effect of a peroxide/bismaleimide curing system and composition

AbstractPolypropylene (PP)/styrene–butadiene rubber blends were studied with special attention given to the effects of the blend ratio and dynamic vulcanization. Dicumyl peroxide (DCP) was used as the curing agent in combination with N,N′‐m‐phenylene bismaleimide (BMI) as the coagent for the curing process. Outstanding mechanical performance, especially with regard to the elongation at break, and better resistance to compression set were achieved with the dynamic vulcanization; this indicated that the DCP/BMI system also acted as a compatibilizing agent. This phenomenon was also confirmed by Fourier transform infrared spectroscopy of the insoluble material, the crystallinity degree of the PP phase (as investigated by X‐ray diffractometry), and scanning electron microscopy. The dynamic mechanical properties of the nonvulcanized and vulcanized blends were also investigated. The aging resistance of the blends was also evaluated. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011