Natural Rubber Blends Research Articles

Advanced and sustainable EMI shielding composites: Natural rubber-nitrile rubber blends enhanced with hydrothermally synthesized Polyaniline Nanofibers and spinel strontium ferrites

Conductive fillers, such as metals and carbon compounds, often exhibit lower compatibility with polymer matrices, leading to agglomeration phenomena that negatively impact the processing and performance of composites. Polyaniline (PANI) nanofibers, with their high conductivity, rapidly create conductive pathways upon contact, reducing current leakage and dielectric loss in composites. To address the compatibility challenges between fillers and matrices, this study adopts a simple, cost-effective approach for synthesizing highly efficient EMI shielding composites. Specifically, we employ hydrothermal synthesis to enhance the properties of PANI nanofibers and spinel strontium ferrites, significantly improving their performance as filler particles. By modifying the morphology of the conductive fillers and incorporating magnetic particles wrapped with an insulating polymer layer, we enhance filler-matrix compatibility. Notably, the synthesized system is a composite made of natural rubber, highlighting its relevance and importance in the current era. This approach not only improves compatibility but also leverages the sustainable properties of natural rubber, making it a significant advancement in the field of EMI shielding materials. In this paper, we report a flexible EMI shielding composite with efficient EM wave absorption, prepared using a natural rubber-nitrile rubber blend as the matrix, and hydrothermally synthesized improves polyaniline nanofibers and spinel strontium ferrite as functional fillers. The shielding efficiency (SET) increases up to 36 dB with different PANI-SrFe2O4wt percentages. This demonstrates the potential of composite for high-performance applications.

Biobased rubber toughened poly(lactic acid) blend for sustainable packaging films: The role of optical purity of poly(lactic acid)

AbstractThis study investigates the novel effect of poly(lactic acid) (PLA) optical purity on PLA/liquid natural rubber (LNR) blend films fabricated by solution casting. An investigation was conducted to examine how different levels of PLA optical purity affect the mechanical, structural, morphological, thermal, and barrier properties of PLA/LNR films. Infrared spectroscopy analysis revealed that the D‐isomer content of PLA significantly affected the chemical interactions between the LNR and PLA. The favorable chemical interaction between the LNR and PLA with a high D‐isomer content also increased the elongation at break by 300%. Morphological investigations proved that the chemical interaction also improved the dispersion and reduced the size of the LNR droplets formed in the PLA matrix. Notably, while low D‐isomer PLA blends showed decreased crystallinity (Xc) upon LNR addition, high D‐isomer PLA blends exhibited increased Xc by 460%, leading to a 42% increase in oxygen transmission rate. Additionally, hydrolytic degradation of high D‐isomer PLA increased by 259% with increasing LNR content. Overall, optical purity of PLA plays an important role in determining the properties of PLA blends.

Improving durability and efficiency in passive direct ethanol fuel cells using a biodegradable polyvinyl alcohol/epoxidized natural rubber membrane

AbstractIn this study, a novel biodegradable polymer electrolyte membrane with reduced fuel crossover, high selectivity, and high conductivity compared with Nafion 117 membrane in direct ethanol fuel cells (DEFCs) has been reported. Herein, polyvinyl alcohol/epoxidized natural rubber (PVA/ENR) blend membranes were synthesized via a simple solution casting method and applied in DEFCs. The structural and physicochemical features of the PVA/ENR blend membranes were examined using FESEM, FTIR, XRD, water absorption, ethanol uptake, swelling ratio and oxidative stability. ENR enhances the chemical, structural, and mechanical characteristics of PVA, making it a valuable material in fuel cell applications. The incorporation of ENR into the PVA matrix results in a compact morphology, excessive multifunctional groups, low fuel crossover, and high selectivity. The optimum membrane thickness achieves the highest selectivity, reaching up to 12.32 × 104 S s cm−3 at 30°C. Additionally, the maximum power density achieved is 19.52 mW cm−2, surpassing that of the Nafion membrane, which is only 14.55 mW cm−2 at 90°C. Furthermore, this biodegradable membrane can sustain operation for 1000 h at 90°C, owing to its ability to maintain hydration for an extended period. This study represents the first attempt to combine PVA and ENR in fuel cells.

Utilization of modified epoxidized natural rubber and zinc oxide on properties of polylactic acid/epoxidized natural rubber blends: Mechanical properties, antibacterial efficiency and biodegradability

Polylactic acid (PLA) is a biopolymer with brittleness and no antibacterial efficiency, which can be solved by the combination with epoxidized natural rubber (ENR) due to polar-polar interaction and with modified zinc oxide nanoparticles (ZnO) regarding the releasing of zinc ions (Zn2+) and reactive oxygen species (ROS). To minimize self-interaction in each PLA and ENR molecular chain, ENR with different % epoxidation was modified (mENR) by grafting with sebacic acid (SA). The addition of mENR with 50 % mol to PLA significantly improved the properties of pure PLA in terms of mechanical and impact properties, toughness, and also provided disinfectant ability. Regarding antibacterial properties, the efficiency against Staphylococcus aureus and Escherichia coli was significantly improved by adding ZnO to the blends. Combination of mENR to PLA matrix during mixing operation increases improved ZnO dispersion and distribution in PLA/mENR blends. Thus, antibacterial efficiency had been enhanced using proper mENR:ZnO concentration ratios in the PLA matrix, relative to other modified ZnO types. Also, incorporation of mENR:ZnO enhanced impact strength and retarded biodegradability of the blends due to hydrophobicity of ENR in PLA matrix. The findings of the blends' properties suggest potential for new functional applications, especially in disinfectant sheet lamination products where strength and protection against bacterial growth together with proper degradation period are required.

Experimental and theoretical investigation of the effect of physical and chemical compatibilization on the properties of thermoplastic elastomers derived from natural rubber and polypropylene blends

The objective of this research was to improve the compatibility between Natural Rubber/Polypropylene NR/PP blends through physical and chemical compatibilization methods. The physical compatibilization involved the use of epoxidized natural rubber/maleic anhydride-grafted polypropylene (ENR50/PP-g-MA) as a dual compatibilizing agent (CA50), while the process of reactive compatibilization entailed chemically modifying NR and PP phases through the grafting maleic anhydride (MA). Several formulations were prepared by melt mixing using a Brabender plasti-corder. The effects of physical and chemical compatibilization on the technical properties were investigated. FTIR analysis revealed the emergence of two distinctive peaks corresponding to the CO group of MA grafted onto PP and NR chains. FTIR analysis has also confirmed the taking place of reactions between the polar functional groups of PP-g-MA and ENR50. The rheological properties indicated that the viscosity of the NR-g-MA/PP-g-MA is lower than those of the control blend and CA50-based NR/PP system. The mechanical and dynamic mechanical findings corroborated the improvement of interfacial adhesion between NR/PP phases, especially for the NR/PP/CA50 system. SEM examination demonstrated a more uniform dispersion of the PP phase in the CA50-based NR/PP, compared to the control blend and NR-g-MA/PP-MA. NR-g-MA/PP-g-MA exhibits greater miscibility and interaction potential compared to the control NR/PP, and less than NR/(ENR50/PP-g-MA)/PP system. DFT calculations further validate the effect of compatibilization methods on TPE blends. Specifically, Quantum molecular descriptors revealed the role of ENR50/PP-g-MA as an intermediary in facilitating compatibility between NR/PP. These findings indicate that the physical compatibilization method approach using ENR50/PP-g-MA as a dual compatibilizer is a potential compatibilizer for NR/PP.

Simultaneous optimization of the vulcanization characteristics and mechanical properties of chloroprene and natural rubber blend by response surface methodology

Chloroprene rubber (CR) is an expensive and frequently used material in many industries. Thus, a blend of natural rubber (NR) and CR can be used to balance cost and product performance. In this research, the primary objective is to achieve the ideal blend of CR/NR rubber for automotive industry by simultaneously optimizing various response variables, including hardness, tensile strength (TS), vulcanization index (CRI), torque difference and Tan δ. This optimization process is carried out using response surface methodology (RSM) and desirability functions. The study delves into examining the influence of accelerators, retarders, curatives, and the ratio of NR in the final batch on both curing characteristics and mechanical properties. The investigation is conducted through the application of analysis of variance (ANOVA) and linear/nonlinear regression models with the assistance of Design Expert 11. When the quantities of the fillers, TMTM80, DP80, S80, and CTPI80, are at their optimum levels of 1.08, 1.78, 3.5, and 0.96 PHR, respectively, and the NR ratio in the final masterbatch is around 27%, the estimated values for Tan δ, hardness, and TS are approximately 0.144, 55.183 Shore A, and 21.085 MPa, respectively. The observations from the validation experiments align with the predicted outcomes, as all response variables fall within the 95% prediction interval. It is noteworthy to mention that prior research has not attempted simultaneous optimization for CR/NR blend, incorporating these fillers.

Evaluation of Viscoelastic Performance and Molecular Structures of Natural Rubber/NBR Blends Reinforced by Carbon Black and Nano-Silica

This study focuses on the evaluation of the dynamic mechanical properties, molecular structure, density, hardness, swelling behavior of natural rubber blends (NR) and nitrile rubber (NBR) reinforced with carbon black and/or nano-silica. An experimental work has been conducted to study of the effects of increasing NR content and incorporating nano-silica on the mechanical properties and molecular structure were studied using dynamic mechanical analysis (DMA) and Fourier transform infrared (FTIR) spectroscopy. The results show that increasing the NR content and/or incorporating nano-silica into the elastomer leads to a higher storage modulus with no significant change in the glass transition temperature. FTIR analysis indicates the compatibility of the polyblends and the presence of oxidation of the main polymer chain generated during the grinding of the rubber. Additionally, the results of the swelling study demonstrate that stronger molecular interactions occur on the surface of the nano-silica between the nitrile radicals in the NBR and the silanol (Si-OH) radicals. These findings suggest that blending NR and NBR with carbon black and/or nano-silica can improve the mechanical properties and compatibility of the resulting polyblends, with potential applications in the development of advanced elastomeric materials.

Optimized sulfur curing of pulse-damping rubber tubes

In pumping systems present in the industrial field, positive displacement pumps are used due to the high manometric loads and the characteristics of the extracted fluid. However, this type of pump provides a pulsating flow in the system that causes large pressure fluctuations, reducing the useful life of the installations. Because of this problem, pulsation dampers (attenuators) are used in the system in order to promote a more continuous flow and the good functioning of the process. In-line type attenuators feature a flexible tube composed of elastomer, whose viscoelastic behavior causes flow attenuation. The objective of this work is to evaluate whether there is a relationship between the sulfur content present in blends of natural rubber (NR) and synthetic rubber of the Butadiene Styrene (SBR) and the performance of tubular attenuators in a pumping system with pulsating flow. Four NR/SBR rubber blends with different sulfur concentrations in the formulation (0.5; 1.5, 3.0 and 4.5 phr) were tested. The rubbers were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and their mechanical properties were analyzed using mechanical tensile tests. The efficiency of the attenuators was evaluated through bench tests that simulate pumping systems in the field. The results of the mechanical tests showed significant relationships with the performance of the attenuators in experimental tests. In attenuation tests, blends with 1.5; 3.0 and 4.5 phr sulfur had attenuation results of 27.06 %, 9.70 % and 1.61 %, respectively. The 0.5 phr attenuator could not withstand the applied loads due to lack of elastic properties. Thus, it was found that materials with a lower modulus of elasticity had greater efficiency in attenuating the pulsating flow and greater compliance, in which the attenuator that was formulated with 1.5 phr of sulfur showed 25.45 % greater pulsation damping than the stiffer material.

Strengthened Poly(vinylidene fluoride)/Epoxidized Natural Rubber Blend by a Reactive Compatibilizer Based on an Amino Acid-Modified Fluorocarbon Elastomer

Strengthened Poly(vinylidene fluoride)/Epoxidized Natural Rubber Blend by a Reactive Compatibilizer Based on an Amino Acid-Modified Fluorocarbon Elastomer

The effect of physical compatibilization and dynamic vulcanization on the properties of thermoplastic vulcanizates derived from polypropylene and natural rubber blends

This interesting study investigated the effect of Maleic Anhydride-grafted-Polypropylene/Epoxidized Natural Rubber (PP-g-MA/ENR) as a compatibilizing agent (CA) on the properties of a 30/70 Polypropylene/Natural Rubber PP/NR blends. The effect of dynamic vulcanization with sulfur-donors (i.e.: Tetramethyl thiuram disulfide (TMTD) and 4,4 Dithiodimorpholine (DTDM)) which were used as vulcanizing agents was also reported. Several formulations of TPVs with different concentrations of CA (from 5 to 15 phr) were prepared by mixing in the molten state using a Haake Rheocord 90. The structural analysis of dual compatibilizer was examined by FTIR spectroscopy. The rheological behavior was examined using Haake Rheocord 90. The mechanical properties were determined by the tensile measurements. The dynamic mechanical thermal properties were investigated by DMA. A morphological examination was conducted using SEM Microscopy, respectively. FTIR analysis confirmed reactions between the MA group in PP-g-MA and the epoxy groups in ENR, resulting in ENR-grafted PP with an ester and acid-based linkage. The Haake plastograms revealed a proportional increase in the final mixing torque value with the increasing content of CA. The mechanical results exhibited higher values in terms of tensile strength and Young’s modulus for the TPVs containing CA compared to un-compatibilized ones. The compatibilized TPV blends exhibited a noteworthy increase in storage modulus and a notable decrease in loss tangent values with the CA concentration increased. Furthermore, the TPVs show two distinct-phase morphologies. That is, the TPV with CA showed the presence of smaller vulcanized rubber particles dispersed within the PP matrix, a phenomenon that becomes more pronounced with higher CA contents.

Sustainable composites with self‐healing capability: Epoxidized natural rubber and cellulose propionate reinforced with cellulose fibers

AbstractAligned with the UN's Sustainable Development Goals (SDGs), self‐healing elastomers stand out as a cutting‐edge field in Rubber Science and Technology. These materials have the potential to reduce resource consumption, prolong the lifespan of infrastructure and products, and contribute to the Circular Economy. This study presents the development of bio‐based self‐healing elastomeric composites prepared from blends of epoxidized natural rubber (ENR) and cellulose propionate (CP) reinforced with cellulose fibers (CFs). The ENR/CP ratio was optimized, with a 70/30 ratio enhancing the tensile strength (TS) of the base rubber and slightly reducing the elongation at break. This blend demonstrated a TS healing efficiency of 75% after a temperature‐driven healing protocol (200 bar at 150°C during 12 h). Then, the CF content was varied to enhance both mechanical performance and self‐healing capabilities. Remarkably, from medium‐high (5 phr to 15 phr) CF content, healing efficiencies higher than 85% were observed with important improvements in the mechanical performance. The self‐healing process was attributed to the synergistic interplay between the polymeric chain mobility and the formation of hydrogen bonds. This innovative approach promises materials with extended lifespans, mechanical robustness, and repairability, underscoring the commitment to SDGs 9, 11, 12, 13, 14, and 15.Highlights Matrix of epoxidized natural rubber (ENR) and cellulose propionate (CP) blends. Cellulose fibers (CFs) reinforced the ENR/CP 70/30 optimized blend. CF addition increases tensile strength (TS) by up to 60%. Healing efficiency over 85% achieved with 5 phr to 15 phr CFs content. Self‐healing attributed to polymeric chain mobility and hydrogen bonds.

Self-heating and fatigue crack growth behavior of reinforced NR/BR nanocomposites with different blending ratio

Fatigue crack growth and dissipative self-heating due to viscoelasticity are crucial properties of rubber materials under dynamic service conditions. Systematic evaluation of the thermo-mechanical coupled fatigue properties with suitable lab testing methods could contribute to the development of long-lasting and robust elastomer materials. In this work, on the one hand, the hysteresis energy density, thermal conductivity, and surface temperature rise, which are closely related to the self-heating generation rate, heat transfer rate and heat build-up of the carbon black reinforced seven different natural rubber (NR) and polybutadiene rubber (BR) blends were measured. A thermo-mechanical coupling simulation method was used to reproduce the experimental observation. On the other hand, the fatigue threshold (T0), critical tearing energy (Tc), and fatigue crack growth rate (FCGR) under different tearing energy were investigated by using the advanced rubber fatigue instruments. The Lake-Lindley model was utilized to describe the rubber fatigue responses from the intrinsic strength to the ultimate strength. The results show that the dissipative self-heating of NR/BR:30/70 blend is the most obvious one, which could be well explained by the simulation results. The T0 shows an upward trend while Tc shows a downward trend with the increasing blend ratio of BR. The existence of carbon black fillers showed tiny effect on T0 of NR, but significantly enhanced the T0 of BR. The FCGR of reinforced NR/BR nanocomposites have Lake-Lindley law responses that cross over each other. Therefore, which rubber material is superior to others in resisting crack propagation depends on the magnitude of the input tearing energy.

Kinetic mathematical model with induction and reversion for the vulcanization of natural rubber and ethylene propylene diene monomer blend

The complexity inherent in modeling and optimizing rubber cure processes stems from the intricate interplay between “induction” and “reversion” phenomena. During the vulcanization process, rubber compounds undergo a gradual initial decrease in torque in an “induction” phase. Following this, the primary vulcanization reaction triggers a swift surge in cross-link density. Interestingly, the density may peak and subsequently decline, leading to compromised mechanical properties with prolonged curing times. This “reversion” phenomenon is extensively documented in sulfur-cured rubbers at elevated vulcanization temperatures, typically exceeding 140 °C. Moreover, the cure conditions can influence the final structure, mechanical performance, and thermal stability of the network.This paper introduces a kinetic mathematical model that is able to predict the optimal time and temperature for a blend of natural rubber and ethylene propylene diene monomer. This model incorporates considerations for both the induction and reversion phases of the vulcanization process. These considerations prove particularly critical, especially in scenarios involving large rubber items or when the rheometer curves of the rubber exhibit a slow pace with significant reversion towards the end. Additionally, the study proposes a novel approach for determining the kinetic variables that concurrently consider all vulcanization temperatures using a standard genetic algorithm.

Enhancing the dynamic mechanical properties of thermoplastic elastomers: A study on polypropylene /natural rubber blends

The aim of this study was to investigate the modifications of the mechanical properties of polypropylene (PP) by incorporating elastomers, while considering the impact on its stiffness. Specifically, the research focused on determining the optimal loading of elastomer to achieve desirable properties and exploring the influence of these processes on the morphology and mechanical behavior of the prepared blends. Thermoplastic elastomers (TPEs) consisting of polypropylene and natural rubber (PP/NR) were prepared using a melt-mixing process, and the mechanical properties of the blends were evaluated. The stress-strain properties of the blends revealed a successful modification of PP, transforming it from a stiff and strong thermoplastic into a stiff and tough thermoplastic elastomer when 10% NR was included in the PP matrix. As the loading of NR increased, a reduction in tensile strength (TS) and modulus (E) of the blends was observed, while elongation at break (EB) increased. The flexural strength of unmodified PP was 45.9 MPa, which decreased with increasing NR loading. Similarly, the impact strength of unmodified PP was 25.8 KJ/m2, whereas the values for 10%, 20%, 30%, and 40% NR inclusion were 30.8, 24.3, 20.6, and 15.2 KJ/m2, respectively. The melt flow index (MFI) of unmodified PP was 14.1 g/10 min, while the values for 10%, 20%, 30%, and 40% NR inclusion were 19.4, 15.7, 11.6, and 10.2 g/10 min, respectively. The best combination of mechanical properties was observed at 10% NR inclusion in the PP matrix. The micrograph of the blends, as observed from SEM micrographs, supported the modification of PP, resulting in the production of TPE with observable adhesion sites, indicating good compatibility between the components. In a nutshell, a significant 47% increase in impact strength was achieved through the modification process.

Synergistic improvement of mechanical, electrical and thermal properties by graphene nanoplatelets in polyaniline incorporated rubbery thermoplastic composites

Here, thermoplastic natural rubber (TPNR) blend filled with polyaniline (PANi) and graphene nanoplatelets (GNPs) was fabricated via melt blending and compression moulding. The synergistic influence of including 1–5 wt% GNPs with 3 wt% PANi in nanocomposites on the mechanical via tensile test, Impedance electrical test, thermal stability via thermogravimetric analysis test and morphologic observation were examined. Inclusion of 2 wt% of GNPs increased by 62.8 % on tensile strength and 151.8 % on Young's modulus of TPNR/PANi. The highest electrical conductivity and thermal stability were achieved in the same nanocomposite composition. With a low loading of GNPs, an electrical conductivity of 2.6 E−9 S/cm was achieved which potential to be a new semi-conductive material. At this optimum content, the scanning electron microscopy micrograph revealed a homogenous distribution of GNPs in the TPNR/PANi blend as well as good matrix-filler interaction. To be practical in real application, cost-effectiveness is another important aspect to be determined. In this work, researchers evaluated the cost-performance of each system (TPNR, TPNR/PANi and TPNR/PANi/GNP) based on material costs, mechanical and electrical properties. Different general trends (positive, negative and synergistic) of cost-efficiency relationship were obtained for different material system and the priority greatly depends on their intended uses.

Influence of Processing Oil Content on Rubber-Filler Interactions in Silica/Carbon Black-Filled Natural Rubber Compounding

To ensure the production of high-quality rubber products, establishing effective compatibility and robusting interactions between rubber and fillers is crucial. Since the rubber production industry faces significant environmental challenges, sustainability is becoming a necessity in the rubber business. Various materials, such as the presence of processing aids, might influence rubber-filler and filler-filler interactions. Petroleum oil as general processing oil has environmental issues, thus it is urgent to replace it with bio-based oil. This study addresses these concerns by investigating the impact of paraffinic oil and bio-based oil content on the interactions between silica/carbon black and natural rubber chains. Ranging from 0 to 10 phr, different dosages of these oils were employed. The rubber compound underwent milling using two rolled laboratory open mills post-blending with a laboratory internal mixer. Subsequently, mechanical properties were assessed. A Rubber Processing Analyzer was utilized to characterize interactions between uncured and cured silica/carbon black-filled natural rubber blends. The results revealed that all variations were distributed uniformly. Tan Delta results confirm that a chemical with a high bio-based oil concentration is easier to process. The carbon black with the largest peak of modulus values at low strain has the highest reinforcing or the poorest dispersion. Compounding with paraffinic oil has a high peak modulus value, resulting in poor dispersion when compared to bio-based oil. This research sheds light on the potential of bio-based oils as an eco-friendly alternative in rubber processing, contributing to sustainability efforts in the industry.

Quantification of natural rubber blends by reflection/reflectance infrared and confocal Raman spectroscopy: a comparison of statistical methods.

The blend of butadiene and acrylonitrile copolymer (NBR) with natural poly-cis-isoprene (NR) shows increased resistance to swelling in solvents in comparison to the individual components. In aerospace, NBR rubber is used as thermal protection for rockets and shall not contain other polymers, even in low contents, otherwise, it can affect the protection performance and rocket safety by causing detachment of the elastomer/propellant interface; therefore, this investigation presents methodologies to determine the NR/NBR contents. This study explores different analytical techniques, such as Raman spectroscopy and Fourier transform infrared (FTIR) spectroscopy, in the mid-infrared (MIR) by reflection and in the near-infrared by reflectance (NIRA) modes, Furthermore, quantification strategies by univariate, bivariate and multivariate (chemometric) models are evaluated and compared. A proposed methodology, based on multivariate Raman microscopy with partial least squares regression (PLS), showed high linearity (R2 > 0.99) and low error (< 0.82 %). The validation of FT-MIR data for the CH3, which presented lower error (1.3%) than vinylidene band (6%), showed that both methodologies (reflection and NIRA reflectance) can be used for the quantification of NR in NR/NBR. These results constitute a contribution to the state of the art in researching industrial and aerospace elastomeric applications.

Thermo-elasticity of multi walled carbon nanotube- natural rubber/acrylonitrile butadiene rubber blends

Natural rubber nano-composites are emerging as one of the key players in the industry and research due to its novel material properties and nano functionalities. In order to create high performance natural rubber nano-composites, new multifunctional nano-fillers can be created using a various approaches due to the advances of nanotechnology. Blends of natural rubber (NR) and acrylonitrile butadiene rubber (NBR) were used to evaluate the effects of various constitutional ratios between the two substances of fixed weight of multi walled carbon nanotubes (MWCNTs). The increase in the frequency of alternating extension (fatigue deformation) for samples (B2, B3) causes an increase in the thermo-elastic temperature change. The breakdown of the structure is thought to be prevailing at high strain amplitude and consequently may account for the observed effect. The thermo-elastic measurements also involve the determination of the thermo-elastic coefficient, change in entropy, internal energy per unit length, and Gruneisen constant. All these parameters were found to be highly dependent on both fatigue parameters and NR/NBR polymer ratios in the composite. The prepared sample (50/50 phr) can be used as thermo-elastic sensors.

Investigation of the usability of activated carbon as a filling material in nitrile butadiene rubber/natural rubber components and modeling by regression analysis

Activated carbon is a versatile material with a wide range of applications due to its porous structure and large surface area. In this study, activated carbon was manufactured from cellulose using zinc chloride and phosphoric acid activation agents, and it was characterized using Brunauer-Emmett-Teller (BET), Field-Emission Scanning Electron Microscopes (FE-SEM), Energy Distribution Spectroscopy (EDS), mapping, and Fourier Transform Infrared Spectrophotometer (FTIR). Two different types of activated carbon utilized as a filler in Nitrile Butadiene Rubber (NBR)/Natural Rubber (NR) blends at different proportions (%0, %5, %10, %15 and 20%), and compared its properties to those of carbon black. The results showed that the addition of activated carbon improved the mechanical properties of the rubber blends, including hardness, tensile strength, and unit elongation. Furthermore, the experimental data obtained were used to examine the effects of carbon black, activated carbon salt, and activated carbon acid values on density, hardness, tensile strength, and percentage elongation variables using Multiple Linear Regressions (MLR). These models provided successful results in predicting the data with fewer experiments. The results have the potential to contribute to the promotion of the use of environmentally friendly materials in future research and to be an important step towards a sustainable industry.

Thermo-Responsive Shape Memory Thermoplastic Elastomer Based on Natural Rubber and Ethylene Octene Copolymer Blends

The shape memory (SM) polymers with superior SM properties were successfully fabricated based on melt blending of natural rubber (NR) and ethylene octene copolymer (EOC) at various crystallinity of EOC phase. The differential scanning calorimetry analysis, mechanical properties, temperature scanning stress relaxation, and shape memory properties were studied. Results revealed that the mechanical and thermal properties of the prepared NR/EOC blends improved as a function of amount of ethylene fraction in the EOC phase. The ethylene segment of EOC in the NR/EOC blend is triggered as a stimulus-sensitive domain. The shape memory properties in terms of shape fixity and shape recovery efficiencies of the blends tended to increase with the increasing of crystalline segments in the blends. The shape memory properties of the prepared blends substantially exceed the best performance (close to 100%) by blending the NR/EOC at 50/50 parts by weight, having 62%–80% of ethylene content in the EOC phase, which corresponds to approximately 3°–16° of crystallinity of EOC phase in the blends.