Ground Tire Rubber Particles Research Articles

Novel Design of Eco-Friendly High-Performance Thermoplastic Elastomer Based on Polyurethane and Ground Tire Rubber toward Upcycling of Waste Tires.

Waste rubber tires are an area of global concern in relation to reducing the consumption of petrochemical products and environmental pollution. Herein, eco-friendly high-performance thermoplastic polyurethane (PU) elastomers were successfully in-situ synthesized through the incorporation of ground tire rubber (GTR). The excellent wet-skid resistance of PU/GTR elastomer was achieved by using mixed polycaprolactone polyols with Mn = 1000 g/mol (PCL-1K) and PCL-2K as soft segments. More importantly, an efficient solution to balance the contradiction between dynamic heat build-up and wet-skid resistance in PU/GTR elastomers was that low heat build-up was realized through the limited friction between PU molecular chains, which was achieved with the help of the network structure formed from GTR particles uniformly distributed in the PU matrix. Impressively, the tanδ at 60 °C and the DIN abrasion volume (Δrel) of the optimal PU/GTR elastomer with 59.5% of PCL-1K and 5.0% of GTR were 0.03 and 38.5 mm3, respectively, which are significantly lower than the 0.12 and 158.32 mm3 for pure PU elastomer, indicating that the PU/GTR elastomer possesses extremely low rolling resistance and excellent wear resistance. Meanwhile, the tanδ at 0 °C of the above-mentioned PU/GTR elastomer was 0.92, which is higher than the 0.80 of pure PU elastomer, evidencing the high wet-skid resistance. To some extent, the as-prepared PU/GTR elastomer has effectively solved the "magic triangle" problem in the tire industry. Moreover, this novel research will be expected to make contributions in the upcycling of waste tires.

Fire-Retardant Flexible Foamed Polyurethane (PU)-Based Composites: Armed and Charmed Ground Tire Rubber (GTR) Particles.

Inadequate fire resistance of polymers raises questions about their advanced applications. Flexible polyurethane (PU) foams have myriad applications but inherently suffer from very high flammability. Because of the dependency of the ultimate properties (mechanical and damping performance) of PU foams on their cellular structure, reinforcement of PU with additives brings about further concerns. Though they are highly flammable and known for their environmental consequences, rubber wastes are desired from a circularity standpoint, which can also improve the mechanical properties of PU foams. In this work, melamine cyanurate (MC), melamine polyphosphate (MPP), and ammonium polyphosphate (APP) are used as well-known flame retardants (FRs) to develop highly fire-retardant ground tire rubber (GTR) particles for flexible PU foams. Analysis of the burning behavior of the resulting PU/GTR composites revealed that the armed GTR particles endowed PU with reduced flammability expressed by over 30% increase in limiting oxygen index, 50% drop in peak heat release rate, as well as reduced smoke generation. The Flame Retardancy Index (FRI) was used to classify and label PU/GTR composites such that the amount of GTR was found to be more important than that of FR type. The wide range of FRI (0.94-7.56), taking Poor to Good performance labels, was indicative of the sensitivity of flame retardancy to the hybridization of FR with GTR components, a feature of practicality. The results are promising for fire protection requirements in buildings; however, the flammability reduction was achieved at the expense of mechanical and thermal insulation performance.

Ground Tire Rubber Particles as Substitute for Calcium Carbonate in an EPDM Sealing Compound.

Ground tire rubber (GTR) is a product obtained by grinding worn tire treads before retreading them or via the cryogenic or ambient temperature milling of end-of-life tires (ELTs). The aim of this study is to evaluate if calcium carbonate can be substituted by GTR and, if so, to what extent. Different types of ground tire rubber are incorporated in an EPDM (ethylene-propylene-diene-rubber) model compound as partial or complete substitutes of calcium carbonate. The raw compounds and the vulcanizates are characterized to identify the limits. In general, it is apparent that increasing amounts of GTR and larger particles degrade the mechanical properties. The GTR also influences the vulcanization kinetics by reducing the scorch time up to 50% and vulcanization time up to nearly 80%. This is significant for production processes. The compounds with one-third substitution with the smaller-particle-size GTR show mostly similar or even better properties than the reference.

Development of Novel Low-Cost Sustainable Abrasive Flow Finishing Media From Ground Tire Rubber and Its Performance Evaluation

Abstract The present experimental endeavor aims to develop and study the characteristics of a novel ground tire rubber media (GTRM) through rheological, thermal, and mechanical characterizations. Thermogravimetric analysis reveals the presence of natural and styrene butadiene rubber in ground tire rubber (GTR) and confirms the thermal stability of developed GTRM under the working temperature of the abrasive flow finishing (AFF) process. Investigation reveals that incorporating GTR into media improves AFF performance up to 50 phr, after which it degrades due to poor self-deforming characteristics and abrasive holding capacity at higher GTR fractions. It has also been observed that the percentage of oil and the size of the GTR particles are significant media parameters that govern the GTRM property and thus influence its performance. GTRM with bigger GTR produces deep abrasive cut marks and nonuniform shearing. A comprehensive study reveals that GTRM containing 50 phr GTR (80 mesh), 10% oil, and 60% SiC (220 mesh) results in the highest percentage improvement in surface roughness (% ΔRa) of 44% on flat geometry. The same media, but with coarser SiC (80 mesh), was also used to polish a micro-grooved workpiece. Results show 64% improvement in Ra for the top surface and 58% for the bottom, respectively. Both surfaces still contain a few pits and unevenness; however, the surfaces and top edge of the groove became smooth after AFF.

Comprehensive Enhancement of Prepolymer-Based Flexible Polyurethane Foams' Performance by Introduction of Cost-Effective Waste-Based Ground Tire Rubber Particles.

Material innovations in polyurethane (PU) foams should ideally combine performance enhancement, environmental impact limitation, and cost reduction. These goals can be achieved by applying recycled or waste-based materials without broader industrial applications, implicating their low price. Herein, from 5 to 20 parts by weight of ground tire rubber (GTR) particles originated from the recycling of postconsumer car tires were incorporated into a flexible foamed PU matrix as a cost-effective waste-based filler. A two-step prepolymer method of foams manufacturing was applied to maximize the potential of applied formulation changes. The impact of the GTR content on the foams’ processing, chemical, and cellular structure, as well as static and dynamic mechanical properties, thermal stability, sound suppression ability, and thermal insulation performance, was investigated. The introduction of GTR caused a beneficial reduction in the average cell diameter, from 263.1 µm to 144.8–188.5 µm, implicating a 1.0–4.3% decrease in the thermal conductivity coefficient. Moreover, due to the excellent mechanical performance of the car tires—the primary application of GTR—the tensile performance of the foams was enhanced despite the disruption of the cellular structure resulting from the competitiveness between the hydroxyl groups of the applied polyols and on the surface of the GTR particles. The tensile strength and elongation at break were increased by 10 and 8% for 20 parts by weight GTR addition. Generally, the presented work indicates that GTR can be efficiently applied as a filler for flexible PU foams, which could simultaneously enhance their performance, reduce costs, and limit environmental impacts due to the application of waste-based material.

Influence of Tire Rubber Particles Addition in Different Branching Degrees Polyethylene Matrix Composites on Physical and Structural Behavior.

Waste from pneumatic wheels is one of the major environmental problems, and the scientific community is looking for methods to recycle this type of waste. In this paper, ground tire rubber particles (GTR) from disused tires have been mixed with samples of low-density polyethylene (LDPE) and high-density polyethylene (HDPE), and morphological tests have been performed using scanning electron microscopy (SEM), as well as the dynamic electric analysis (DEA) dielectric characterization technique using impedance spectroscopy. From this experience, how GTR reinforcement influences polyethylene and what influence GTR particles have on the branched polyethylene has been detected. For pure LDPE samples, a Debye-type dielectric behavior is observed with an imperfect semicircle, which depends on the temperature, as it shows differences for the samples at 30 °C and 120 °C, unlike the HDPE samples, which do not show such a trend. The behavior in samples with Debye behavior is like an almost perfect dipole and is due to the crystalline behavior of polyethylene at high temperature and without any reinforcement. These have been obtained evidence that for branched PE (LPDE) the Maxwell Wagner Sillars (MWS) effect is highly remarkable and that this happens due to the intrachain polarization effect combined with MWS. This means that the permittivity and conductivity at LDPE/50%GTR are high than LDPE/70%GTR. However, it does not always occur that way with HDPE composites in which HDPE/70%GTR has the highest values of permittivity and conductivity, due to the presence of conductive fraction (Carbon Black-30%) in the GTR particles and their dielectric behavior.

Strain induced crystallization in vulcanized natural rubber containing ground tire rubber particles with reinforcement and nucleation abilities

Strain induced crystallization (SIC) of peroxide vulcanized natural rubber (NR)/ground tire rubber (GTR) composites is studied by combining mechanical and microstructural characterization techniques. It is found that the incorporation of GTR into the NR matrix leads to more effective reinforcement at large strains at room temperature in the NR/GTR composites as compared to the neat NR. It is attributed to (i) the presence of the GTR particles acting as reinforcing fillers owing their high carbon black content, and (ii) the nucleating effect of the GTR for SIC in the NR matrix inducing further reinforcement through the generation of an increasing number of oriented crystallites that behave as supplementary reinforcing fillers.

SBR Vulcanizates Filled with Modified Ground Tire Rubber.

Ground tire rubber (GTR) is used to decrease the cost of vulcanizates. However, insufficient interactions between GTR particles and rubber matrices make mechanical properties of vulcanizates containing GTR deteriorate. This paper compares original methods of GTR modification. The effects of surface activation of GTR by sulfuric acid (A), its modification by (3-mercaptopropyl)trimethoxy silane (M), or the hybrid treatment—combining both approaches (H), were analyzed in terms of surface energy, specific surface area and morphology of GTR particles. Vulcanizates containing virgin GTR were compared to the rubber filled with the modified GTR particles keeping the same amount of CB in the rubber mix, according to their crosslink density, mechanical and tribological properties. Contrary to the virgin GTR, the addition of modified GTR increases the stiffness of the vulcanizates. The highest changes have been observed for the samples filled with ca. 12 phr of the GTR modified with silane and ca. 25 phr of the GTR subjected to the hybrid treatment, representing the highest crosslink density of rubber vulcanizates filled with GTR. Furthermore, the addition of modified GTR, especially in the case of the samples where 10 phr of rubber was replaced, results in the significant lowering of friction but higher abrasive wear.

Ground Tire Rubber Filled Flexible Polyurethane Foam-Effect of Waste Rubber Treatment on Composite Performance.

The application range of flexible polyurethane (PU) foams is comprehensive because of their versatility and flexibility in adjusting structure and performance. In addition to the investigations associated with further broadening of their potential properties, researchers are looking for new raw materials, beneficially originated from renewable resources or recycling. A great example of such a material is ground tire rubber (GTR)—the product of the material recycling of post-consumer car tires. To fully exploit the benefits of this material, it should be modified to enhance the interfacial interactions between PU and GTR. In the presented work, GTR particles were thermo-mechanically modified with the addition of fresh and waste rapeseed oil in the reactive extrusion process. The introduction of modified GTR particles into a flexible PU matrix caused a beneficial 17–28% decrease in average cell diameters. Such an effect caused an even 5% drop in thermal conductivity coefficient values, enhancing thermal insulation performance. The application of waste oil resulted in the superior mechanical performance of composites compared to the fresh one and thermo-mechanical modification without oils. The compressive and tensile performance of composites filled with waste oil-modified GTR was almost the same as for the unfilled foam. Moreover, the introduction of ground tire rubber particles enhanced the thermal stability of neat polyurethane foam.

Effect of Ground Tire Rubber (GTR) Particle Size and Content on the Morphological and Mechanical Properties of Recycled High-Density Polyethylene (rHDPE)/GTR Blends

This work investigates the effect of ground rubber tire (GRT) particle size and their concentration on the morphological, mechanical, physical, and thermal properties of thermoplastic elastomer (TPE) blends based on recycled high-density polyethylene (rHDPE). In our methodology, samples are prepared via melt blending (twin-screw extrusion followed by compression molding) to prepare different series of blends using GTR with three different particle sizes (0–250 μm, 250–500 μm, and 500–850 μm) for different GTR concentrations (0, 20, 35, 50, and 65 wt.%). The thermal properties are characterized by differential scanning calorimeter (DSC), and the morphology of the blends is studied by scanning electron microscopy (SEM). The mechanical and physical properties of the blends are investigated by quasi-static tensile and flexural tests, combined with impact strength and dynamic mechanical analysis (DMA). The SEM observations indicate some incompatibility and inhomogeneity in the blends, due to low interfacial adhesion between rHDPE and GTR (especially for GTR > 50 wt.%). Increasing the GTR content up to 65 wt.% leads to poor interphase (high interfacial tension) and agglomeration, resulting in the formation of voids around GTR particles and increasing defects/cracks in the matrix. However, introducing fine GTR particles (0–250 μm) with higher specific surface area leads to a more homogenous structure and uniform particle dispersion, due to improved physical/interfacial interactions. The results also show that for a fixed composition, smaller GTR particles (0–250 μm) gives lower melt flow index (MFI), but higher tensile strength/modulus/elongation at break and toughness compared to larger GTR particles (250–500 μm and 500–850 μm).

Development of high-performance thermoplastic composites based on polyurethane and ground tire rubber by in-situ synthesis

The aim of this paper is to make full use of the hydroxyl groups on the ground tire rubber (GTR) surface to realize the high valuable utilization of waste tires in the field of high-performance polyurethane elastomers. In this work, the Polyurethane/Ground tier rubber (PU/GTR) thermoplastic composite with excellent performance was in-situ synthesized by adding untreated GTR to polyurethane. With incorporating 3.44 wt% GTR to polyurethane, the tensile strength of the PU/GTR thermoplastic composites was improved by approximately 166.7 % compared with pure PU. And the dynamic heat generation index (ratio of the tan δ at 90 °C and 30 °C) of the thermoplastic composites was reduced to 0.97, being far lower than that of pure PU (1.62), which exhibits this material has low dynamic heat generation when subjected to alternating stress. As expected, X-ray photoelectron spectra (XPS) results showed that the GTR indeed participated in the in-situ synthesis of polyurethane, thus, resulting in the GTR particles with micro size being evenly distributed in the polyurethane matrix via a network structure, which was proved by the morphology analysis and rheological measurement part. Additionally, the microphase separation of the PU matrix of the composites was greatly weakened according to Cole-Cole plots and the small angle X-ray scattering (SAXS) analysis. And the outcome of the study provided a low-cost and rational approach for recycling of waste tires while avoiding resource waste.

Mechanochemical devulcanization of waste tire rubber in high pressure water jet pulverization

The resource reclamation of waste tire rubber (WTR) is regarded as the most suitable strategy for these solid wastes. Water jet pulverization (WJPul) is a sustainable reclamation technique for WTR, since both size reduction and rubber devulcanization can be achieved. Aiming at understanding the mechanisms related with pulverization and devulcanization of WTR, this work detailed the interactions between WTR and high pressure water jet (HPWJ). The results show that WJPul can be defined as a mechanochemical process for WTR. The compressive shear failure of rubber mainly induces rubber devulcanization and results in fine ground tire rubber (GTR) particles, HPWJ erosion mainly intensifies rubber depolymerization and results in coarse GTR particles. Chemical reactions can be detected between the devulcanized GTR from WJPul and asphalts, thus resulting in better modification performances of GTR from WJPul in asphalt. The results can help better understand the WJPul mechanisms and provide guidelines for WJPul application.

Poly (Lactic Acid)/Ground Tire Rubber Blends Using Peroxide Vulcanization.

Poly (Lactic Acid) (PLA)/Ground Tire Rubber (GTR) blends using Dicumyl peroxide (DCP) as a crosslinking agent were prepared with the following aims: propose a new route to recycle wastes rubber from the automotive industry and improve the toughness and impact strength of the inherently brittle bio-based PLA. The GTR were subjected to two types of grinding process (cryo- and dry ambient grinding). Swelling measurements revealed the grinding to be associated with a mechanical damage of the rubber chains, independently on the type of grinding or on the GTR size (from <400 µm to <63 µm). Moreover, the finest GTR contains the largest amount of reinforcing elements (carbon black, clay) that can be advantageously used in PLA/GTR blends. Indeed, the use of the finest cryo-grinded GTR in the presence of DCP showed the least decrease of the tensile strength (−30%); maintenance of the tensile modulus and the largest improvement of the strain at break (+80%), energy at break (+60%) and impact strength (+90%) as compared to the neat PLA. The results were attributed to the good dispersion of both fine GTR and clay particles into the PLA matrix. Moreover, a possible re-crosslinking of the GTR particles and/or co-crosslinking at PLA/GTR interface in presence of DCP is expected to contribute to such improved ductility and impact strength.

Structural Changes and Their Implications in Foamed Flexible Polyurethane Composites Filled with Rapeseed Oil-Treated Ground Tire Rubber

The utilization of post-consumer car tires is an essential issue from an ecological and economic point of view. One of the simplest and the least harmful methods is their material recycling resulting in ground tire rubber (GTR), which can be further applied as fillers for polymer-based composites. Nevertheless, insufficient interfacial interactions implicate the necessity of GTR modification before introduction into polymer matrices. In this study, we investigated the influence of rapeseed oil-assisted thermo-mechanical treatment of GTR using a reactive extrusion process on the processing, structure, and performance of flexible polyurethane/GTR composite foams. Applied modifications affected the processing of polyurethane systems. They caused a noticeable reduction in the average cell size of foams, which was attributed to the potential nucleating activity of solid particles and changes in surface tension caused by the presence of oil. Such an effect was especially pronounced for the waste rapeseed oil, which resulted in the highest content of closed cells. Structural changes caused by GTR modification implicated the enhancement of foams’ strength. Mechanical performance was significantly affected by the applied modifications due to the changes in glass transition temperature. Moreover, the incorporation of waste GTR particles into the polyurethane matrix noticeably improved its thermal stability.

Ground Tire Rubber Recycling in Applications as Insulators in Polymeric Compounds, According to Spanish UNE Standards

In the present research, we investigated the conceivable outcomes of using ground tire rubber (GTR) particle polymeric blends. Special methods of restoring tires that are no longer in use include GTR retreading, GTR blending destined for recycling to attain raw substances utilized in other industrial application production processes, and the valorization of GTR for power/energy generation. The recycling of end-of-life tires enables the recovery of rubber, steel, and fibers, all of which are valid on the market as raw materials to be used for other processes. There are methods to recycle GTRs in a clean and environmentally friendly way. In the present research, several industrial applications of GTR polymer blends were developed and compared with standard values from the Spanish Association for Standardization (UNE) and the International Electrotechnical Commission (IEC). In order to analyze the viability in many of the industrial applications selected, certain compounds obtained from the GTR polymer blends were analyzed regarding their use in nine low requirement insulator applications. The research and analysis developed in this manuscript used standard values from the UNE and IEC, and these standard values were compared with the test values. The obtained results were used to provide an application list that could be helpful for industrial applications. In this research, the pre-owned polymers were as follows: polypropylene (PP), high-density polyethylene (HDPE), polystyrene (PS), acrylonitrile butadiene-styrene (ABS), ethylene vinyl acetate (EVA), polyvinyl chloride (PVC), and polyamide (PA). The filler used was GTR with particle sizes lower than 200 microns. The amounts of GTR particles in the compound materials were 0% (raw polymer), 5%, 10%, 20%, 40%, 50%, and 70% (the latter being found in polymeric blends). We discovered six plausible modern applications of GTR polymer blends as indicated by the UNE and IEC standards.

Surface modification of ground tire rubber particles by cold plasma to improve compatibility in rubberised asphalt

ABSTRACT The inert surface of Ground Tire Rubber (GTR) particles results in its weak compatibility with asphalt matrix and thus causes serious phase separation in rubberised asphalt. Meanwhile, plasma treatment is able to modify the polymer surface effectively. This study applied cold plasma to modify the surface of GTR particles for compatibility improvement in rubberised asphalt. The surface characteristics of plasma-treated GTR particles with varying treatment power and time were investigated, by means of water contact angle metre, X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscope (SEM), respectively. The results reported the enhanced surface hydrophilicity, lipophilicity, and roughness as well as the incorporation of oxygen-containing functional groups of GTR particles after plasma treatment. The optimal processing parameters were determined as the discharge power of 250 W and the processing time of 8 min. The GTR-asphalt compability after the most effective plasma treatment was evaluated by measuring the storage stability and rotational viscosity of rubberised binder. Regardless of base asphalt source, GTR particle size and dosage, cold plasma treatment truly enhanced the compatibility. Furthermore, the increased dosage from 10% to 20% and the decreased size from 30 to 80 mesh generally had a growing positive effect on compatibility.

Tire Recycled Rubber for More Eco-Sustainable Advanced Cementitious Aggregate

This research focused on using ground tire rubber (GTR) with different grain sizes as a replacement for the mineral aggregates used in a cement-based mixture suitable for extrusion-based Additive Manufacturing. The use of two types of GTR particles and the possibility to apply rubberized mixtures in advanced manufacturing technologies are the innovative aspects of this work. At the base of this strategy is the possibility of achieving cementitious aggregates, which would potentially be improved regarding some technological-engineering requirements (lightness, thermal-acoustic insulation, energy dissipation capacity, durability) and environmentally sustainable. The integration of waste tires into cement-based materials is a promising solution for the reuse and recycling of such industrial waste. In addition, this approach may involve a considerable reduction in the use of natural resources (sand, water, coarse mineral aggregates) needed for the building materials production. The purpose of the research was to investigate the effect of sand-GTR replacement on certain chemical-physical properties of mixtures (permeable porosity, surface wetness, and water sorptivity), closely related to material durability. Besides, the role of rubber on the printability properties of the fresh material was evaluated. GTR fillers do not alter the rheological properties of the cement material, which was properly extruded with better print quality than the reference mixture. Concerning chemical-physical characterization, the GTR powder-granules synergy promotes good compaction of the mixture, hinders the cracks propagation in the cement matrix, decreases the permeable porosity, improves the surface hydrophobicity and preserves optimal water permeability.

Engineering and rheological properties of asphalt binders modified with microwave preprocessed GTR

Many researches and field applications have proven that binders modified with ground tire rubber (GTR) can significantly improve rutting resistance potential and durability of asphalt pavement. However, GTR modified asphalt binder has higher viscosity and poorer hot storage stability than base one resulting in construction troubles, such as more energy consumption, extra stirring, reduction in asphalt mixtures performance and etc. The objective of this study was to investigate the engineering and rheological properties of binders prepared with microwave preprocessed GTR at high service temperature, medium temperature, and low temperature, respectively. The experiment included two particle sizes of GTR and five microwave preprocessing radiation intensities. The dynamic shear rheometer (DSR), force ductility test (FDT) and hot storage test were performed to evaluate the effect of radiation intensities and particle sizes of GTR on the engineering and rheological characteristics from low to high temperature. The test results show that microwave preprocessed GTR modified binders presented a reduction trend in composite viscosity, as well as rutting resistance potential after exposing to microwave radiation. In addition, fatigue and low temperature tension properties were jointly affected by microwave radiation intensities and GTR particle size. Otherwise, lower phase separation tendency compared with binder modified with GTR without microwave radiation was observed in this study. Thus, comprehensive consideration of radiation intensities and GTR particles sizes were recommended to apply in the field.

Study and Characterization of the Dielectric Behavior of Low Linear Density Polyethylene Composites Mixed with Ground Tire Rubber Particles.

The waste rubber vulcanizate, on account of its stable, cross-linked and three-dimensional structural arrangement, is difficult to biodegrade. Thus, the ever-increasing bulk of worn-out tires is a serious environmental issue and its safe disposal is still a challenging task reported widely by the scientific community. The rubber materials, once they end their useful life, may present difficulties to be reused or recycled. At present, only one tire recycling method is used, which involves grinding and separating steel and fibers from vulcanized rubber, and then using rubber for industrial applications, such as flooring, insulation, footwear. In this paper, a new compound material is presented from a base of reused tire powder (Ground Tire Rubber: GTR) as a mixer and linear low-density polyethylene (LLDPE) as a matrix. The reused tire powder, resulting from grinding industrial processes, is separated by sieving into just one category of particle size (<200 μm) and mixed with the LLDPE in different amounts (0%, 5%, 10%, 20%, 40%, 50% and 70% GTR). Due to the good electrical properties of the LLDPE, this study’s focus is settled on the electrical behavior of the obtained composites. The test of the dielectric behavior is carried out by means of DEA test (Dynamic Electric Analysis), undertaken at a range of temperatures varying from 30 to 120 °C, and with a range of frequencies from 1 to 102, to 3·106 Hz, from which permittivity, conductivity, dielectric constant and electric modulus have been obtained. From these experimental results and their analysis, it can be drawn that the additions of different quantities of GTR to LLDPE could be used as industrial applications, such as universal electrical cable joint, filler for electrical applications or cable tray systems and cable ladder system.

Grafting of Styrene on Ground Tire Rubber Particles in a Batch Polymerization Reactor: Dynamic Real-Time Optimization

This paper deals with the development of a dynamic real-time optimization (D-RTO) methodology and its experimental use in optimal operation of a batch reactor where polymer grafting reactions take place. It combines a constrained dynamic optimization method with a moving horizon state estimator within closed-loop control. The objective is to determine the online reactor temperature profile that minimizes the batch final time while meeting terminal constraints on the overall conversion rate and grafting efficiency. The methodology is first implemented in open-loop control in order to set up the experimental procedure and at the same time to assess the model accuracy. It is then implemented in closed-loop control, and the resulting computed and measured optimal profiles of temperature, monomer conversion rate, and grafting efficiency exhibit very good agreement and show also that the terminal constraints are satisfied.