Amount Of Rubber Research Articles

Characterization of an eco-friendly rubber composite material based on Sansevieria cylindrica fibers

The weak bonding of the natural fiber in its raw state, with easy breakage and extreme moisture absorption, has many flaws, disadvantages, such as low load-bearing capacity. In addition, these factors are at the root of a mixture of fibers that control the performance or properties. In this paper, the surface is alkali-modified on Sansevieria Cylindrica fibers to overcome the above limitations and the treated fibers are introduced in the maximum viable agglomeration-free amount of 30% (assuming natural rubber quantity as equal to 100) to act as the reinforcement for new composites. Tensile, tear properties and Shore A hardness of the obtained composites, indicated as Sansevieria Cylindrica rubber composites (SCRC), with respect to neat rubber and untreated fibers composites are analyzed and the fracture morphology of treated fiber composites is also elucidated.

Pinkish-achened form of Taraxacum hybernum Steven – a source of inulin and high molar mass natural rubber

ABSTRACT Taraxacum hybernum Steven (Asteraceae family) native to Southeast Europe is a promising rubber-bearing dandelion species. In the 1930s, several phenotypically distinct forms were described in this dandelion, such as brown-achened and pinkish-achened. More than 70 years after termination of research of temperate zone rubber-bearing plants we were able to find both forms of this species of dandelion in natural habitat. The species is still poorly studied, and there is no information about the differences in the quality and quantity of rubber between brown-achened and pinkish-achened forms. Therefore, the purpose of our study was to analyze the root morphology and yield, the rubber and inulin content, and to determine the molar mass of rubber in brown-achened and pinkish-achened T. hybernum. These two forms of T. hybernum, as well as T. kok-saghyz Rodin and T. brevicorniculatum Korol., were studied. The results show that the root shape most attractive for domestication is typical of brown-achened T. hybernum. The greatest mass of roots was gained for pinkish-achened T. hybernum. The rubber content was about 6% in T. kok-saghyz, 3% in both forms of T. hybernum, and 1.5% in T. brevicorniculatum per dry root mass. Taraxacum kok-saghyz and pinkish-achened T. hybernum turned out to be the leaders in inulin content. Of all four dandelions, the molar mass of rubber was more than 1 million g/mol only for T. kok-saghyz and pinkish-achened T. hybernum. Pinkish-achened T. hybernum is a good alternative for T. kok-saghyz and can be recommended for domestication and cultivation in the temperate zone.

Recycling waste rubber particles for the maintenance of different states of railway tracks through a two-step stoneblowing process

Abstract Injecting recycled rubber particles under the sleeper through a two-step stoneblowing technique (partially replacing the small stones with rubber) could improve the performance of ballasted railway tracks. In addition, this results in fewer environmental impacts associated with maintenance whilst recycling an abundant waste material (End-of-Life-Tyres, or ELTs). Nonetheless, to continue the development of this solution before its widespread application, this paper assesses the volumes and dosages of rubber to be used during the correction of various levels of irregularities and track states. The aim is to extend the service life of the track whilst optimizing performance by the inclusion of the elastic particles (particularly in transition sections where gradual variation of track behavior is required). For this purpose, innovative laboratory tests were used to study the effect of applying various quantities of rubber (recycled from ELTs) over small stones to correct three different levels of settlement. This paper presents the resulting guide values for the volumes of small stones and rubber particles to be added. These values depend on the level of track settlement to be corrected and the need for resilience according to the section and characteristics of traffic to be supported. Further, it appears that it is preferable to add the rubber after the compaction of the layer of small stones, which results in a lower tendency towards settlement and irregularities. Therefore, the current findings indicate that a two-step stoneblowing process (adding appropriate quantities of rubber) could be a cleaner technique for improving track behavior and reducing environmental impacts associated with maintenance.

Defining the process of including sustainable rubber particles under sleepers to improve track behaviour and performance

The inclusion of rubber particles derived from end-of-life tyres (ELTs) under the sleepers has been demonstrated in previous studies to be a potential solution to improve the behaviour and durability of railway tracks, and then, minimizing the negative impacts associated with the need for maintenance. Nonetheless, more in-depth studies are still required to define the optimal procedure prior to its application in real tracks. The present paper therefore focused on assessing the main parameters for defining the procedure for adding rubber particles to create an elastic layer under sleepers through a two-step stoneblowing process. Such parameters included the size of the rubber particles; the position of the elastic layer (above or below the conventional small aggregates used in the stoneblowing process); the need to compact the first layer before injecting the subsequent one; the effect of rubber dosage; and the impact of service conditions (traffic levels and temperatures). For this purpose, a number of laboratory tests were carried out on testing boxes simulating the effects of train passages, assessing diverse properties such as particles percolation, section settlement, stiffness and dissipated energy. The results revealed that the inclusion of rubber particles (ranging between 14 and 20 mm) as an elastic layer over the compacted small stones through a two-step stoneblowing process, provides an effective solution to graduate and optimize global track behaviour by using different quantities of rubber, which could reduce the need for track maintenance and its environmental impacts.

Forecasting equilibrium quantity and price on the world natural rubber market

Natural rubber on the world market has had small increases in demand and big increases in supply. Therefore, demand and supply are imbalanced and this impacts the natural rubber price of the world market causing a decline. This study aimed: (1) to develop demand and supply models to predict the world natural rubber quantity using simultaneous equations; (2) to predict all explanatory variables in the demand and supply models using the simple moving average technique; and (3) to estimate the equilibrium quantity and price for world natural rubber during 2017–2026. First, in the demand model, there was a positive relationship of the explanatory variables of world natural rubber production quantity, synthetic rubber price, percentage year of year (%YOY) of gross domestic product (GDP), and the exchange rate, while the negative relationship variable was natural rubber price. In the supply model, the positive relationship variables were natural rubber price, mature area, rainfall, and crude oil price, while the negative relationship variables were world natural rubber stock and urea price. Second, the predicted variables indicated that production, %YOY of GDP, exchange rate, amount of stock, and the mature area tended to gradually increase, while the synthetic rubber price, urea price, rainfall, and crude oil price tended to slowly decrease from 2017 to 2026. Finally, the equilibrium quantity forecast tended to gradually increase from 953.75 to 957.15 thousand tonnes, and the equilibrium price tended to fluctuate and decrease from 169.78 to 162.05 thousand yen from 2017 to 2026. Consequently, this study may be helpful to the governments of the world's important natural rubber producing countries to plan policies to reduce natural rubber production costs and stabilize the natural rubber price in the future, such as by setting suitable areas of world natural rubber plantation in each country, and defining appropriate and sustainable alternative crop areas in each country.

Solving the Location Routing Problem of the Central Rubber Market by Tabu Search

The central rubber market of Songkhla province is the center of the collection and distribution of rubber production from sellers to purchasers. It is considered ineffective because sellers need to deliver whole raw rubber to the market, resulting in high transport costs, especially for those who came a great distance and had little quantity. This research applied the tabu search method to solve the location selection problem of the rubber purchasing depot and manage transport routes to the market. Results found that there were 16 purchasing depots. The central rubber market had unlimited purchasing capacity while the other purchasing depots limited the quantity of rubber to 10 tons. There were five transport routes and five trucks (four ten-wheeled trucks and one ten-wheeled truck with a trailer). The total delivery costs were 53,313.89 baht per day. The answers about efficiency from the Lingo 13 program with small, medium, and large problems and real problems were not significantly statistically different at a significance level of 0.05.

Analysis of the bearing capacity of unbound granular mixtures with rubber particles from scrap tyres when used as sub-ballast

Scrap tyres are a problematic waste material. As a method for recycling large quantities of rubber from scrap tyres, this paper analyses the use of unbound granular mixtures with varying percentages of rubber particles as sub-ballast in railway lines. Bearing capacity for such mixtures is studied in laboratory and field tests using static and dynamic plate load tests, as well as cyclic triaxial tests. It is found that adding rubber increases permanent and resilient strain and that none of the mixtures suffer plastic creep after 2.5 million cycles. Considering the usual bearing capacity requirements, the optimum rubber content is 2.5% (by weight). This percentage increases resistance to degradation while ensuring sufficient bearing capacity.

A study into the use of crumb rubber in railway ballast

Ballasted track is the most common form of construction used in railway transportation due to a number of benefits in comparison with other solutions such as slab track. However, the degradation of the ballast particles and the layer settlement lead to important maintenance costs. Thus, diverse research has been carried out to develop new materials with the aim of increasing the service life of the track. To this end, the present paper focuses on the use of crumb rubber (from end-of-life tires) as elastic aggregates mixed with ballast particles, which could reduce ballast degradation and consumption of natural aggregates. At the same time, an abundant waste source is reused and the use of raw binders (proposed technique employed to bond elastic particles to ballast particles) is not necessary, which potentially reduces costs and consumption of raw materials. For this reason, the influence of different percentages of crumb rubber was studied in the laboratory using a ballast box. In addition, once the optimal quantity of rubber had been determined, its effect on ballast behaviour under high stress level was analysed. Results show that the use of 10% of crumb rubber (by volume) could reduce ballast degradation and at the same time as the capacity of the ballast layer to dissipate energy is increased and its stiffness is reduced. Additionally, based on the present laboratory study, the track settlement could be reduced with 10% rubber particles used as elastic aggregates.

Experimental Study on Ratio of Bending-Compressive Strength of the Crumb Rubber Concrete Modified by Latex

The cementitiousness between rubber particles and cement-based material could be raised because of the surface modification of rubber,thus enhance the mechanical property of crumb rubber concrete and improve the interface effect of rubber particles.We had researched the change regulation about the ratio of bending-compressive strength of the crumb rubber concrete modified by latex,the concrete with various quantity of rubber,under the condition dosage of latex is 0.5% of cement quality.The result of experimental prove that,compressive strength, splitting tensile and flexural strength could be enhanced because of latex injecting,and the ratio of bending-compressive strength could be enhanced at the same time.

Experimental Study on the Mechanical Properties of the Crumb Rubber Concrete Modified by Silane Coupling Agent

Organic molecule and Inorganic molecular could be bind by silane coupling agent,the cementitiousness between rubber particles and cement-based material could be raised because of the surface modification of rubber,thus enhance the mechanical property of crumb rubber concrete.We had researched the change regulation of Mechanical Properties,such as compressive strength,splitting tensile strength and flexural strength of the Crumb Rubber Concrete Modified by silane coupling agent with various quantity of rubber,under the condition Dosage of silane coupling agent is 0.5% of cement quality.

Experimental Study on Proportion of Tensile Strength and Compressive Strength of the Crumb Rubber Concrete Modified by Latex

The cementitiousness between rubber particles and cement-based material could be raised because of the surface modification of rubber,thus enhance the mechanical property of crumb rubber concrete and improve the interface effect of rubber particles.We had researched the change regulation of the ratio between tensile strength and compressive strength of the Crumb Rubber Concrete Modified by latex,the concrete with various quantity of rubber,under the condition Dosage of latex is 0.5% of cement quality.The result of Experimental prove that,compressive strength, splitting tensile and flexural strength could be enhanced because of latex injecting,and the ratio between tensile strength and compressive strength could be enhanced at the same time.

Experimental Study on the Mechanical Properties of the Crumb Rubber Concrete Modified by Silica Fume

For researching the way of modified and mechanism of action of the Crumb Rubber Concrete,we had researched the change regulation of Mechanical Properties and compressive strengthsplitting tensile strengthflexural strength of the Crumb Rubber Concrete Modified By Silica Fume with various quantity of rubber,in the condition of 10% silica fume.the experimental result make it clear that silica fume is propitious to heighten compressive strengthsplitting tensile strengthflexural strength of the Crumb Rubber Concrete,and compressive strengthsplitting tensile strengthflexural strength would be cut down when mix the Crumb rubber in Concrete.

A Study on Transhipment Model for Export of Rubber from Tripura to Bangladesh

Production of rubber in Tripura is the second largest after Kerala. But a less quantity is locally utilized compare to other rubber producing states. A large quantity of rubber is transported to different parts of the country. But transportation costs at present is not so much favourable for the firms or agencies due to frequent price hike of petroleum. Bangladesh is the neighbouring country of Tripura. Bilateral trading now a days is functioning smoothly. Industrialization in rubber sector in Bangladesh needs a sizable quantity of rubber. For exportation of rubber from Tripura to Bangladesh, a transhipment model is considered to minimize the transportation costs.

A Review on the Effect of Crumb Rubber Addition to the Rheology of Crumb Rubber Modified Bitumen

Crumb rubber modification has been proven to enhance the properties of pure bitumen. This paper looks at some of the international standards for producing crumb rubber modified bitumen (CRMB) and reviews the effect of crumb rubber to the rheology of crumb rubber modified bitumen. The review shows that the rheology of CRMB depends on internal factors such as crumb rubber quantity, particle size, and pure bitumen composition, and external factors such as the mixing time, temperature, and also the modification technique. These factors govern the swelling process of crumb rubber particles that lead to the increase of viscosity of the modified bitumen. However, the mixing temperature and duration can cause rubber particles to depolymerize and subsequently cause loss of viscosity. Crumb rubber modification also improves the properties of bitumen by increasing the storage and loss modulus and enhancing the high and low temperature susceptibility. The effect of crumb rubber to aging properties of CRMB is also discussed. Finally several techniques of chemical modification to terminal blends of CRMB and the subsequent improvement to the settling property of CRMB are explained.

Study and Control of the Distribution of Elastomer in High Impact Polypropylene

AbstractIn an initial step, different techniques were used to investigate the distribution and properties of the rubbery domains inside individual high impact polypropylene particles. Both Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) were used to visualise the local of rubber nodules as a function of the quantity of ethylene propylene rubber (EPR) in the final product. It was demonstrated that the EPR forms first as nodules near the centre of the homopolymer particles, and then accumulates as the rubber quantity increases.

Introducción a la biomecánica del pie (VI)

Injecting recycled rubber particles under the sleeper through a two-step stoneblowing technique (partially replacing the small stones with rubber) could improve the performance of ballasted railway tracks. In addition, this results in fewer environmental impacts associated with maintenance whilst recycling an abundant waste material (End-of-Life-Tyres, or ELTs). Nonetheless, to continue the development of this solution before its widespread application, this paper assesses the volumes and dosages of rubber to be used during the correction of various levels of irregularities and track states. The aim is to extend the service life of the track whilst optimizing performance by the inclusion of the elastic particles (particularly in transition sections where gradual variation of track behavior is required). For this purpose, innovative laboratory tests were used to study the effect of applying various quantities of rubber (recycled from ELTs) over small stones to correct three different levels of settlement. This paper presents the resulting guide values for the volumes of small stones and rubber particles to be added. These values depend on the level of track settlement to be corrected and the need for resilience according to the section and characteristics of traffic to be supported. Further, it appears that it is preferable to add the rubber after the compaction of the layer of small stones, which results in a lower tendency towards settlement and irregularities. Therefore, the current findings indicate that a two-step stoneblowing process (adding appropriate quantities of rubber) could be a cleaner technique for improving track behavior and reducing environmental impacts associated with maintenance.

Investigation of mechanical and physical properties of several industrial rubbers

Abstract Recently, blending of polymers has become an increasingly important area of research activity. Elastomer blends are used for many reasons such as lowering the compound cost, for ease of fabrication and to improve the performance of the industrial rubber. Natural rubber (NR) and styrene–butadiene rubber (SBR) have been blended for a long time for these reasons. In this study, 12 different rubber compounds were prepared by using SMR-20 type of natural rubber and SBR-1502 type of styrene–butadiene rubber in different proportions, keeping fixed the total rubber quantity specified in the standard testing recipe. The mechanical and physical properties – such as tensile strength, hardness, wear, carbon black, ozone resistance, density and rheological properties of the present industrial rubber – were studied. Physical and mechanical test results were reported. The tensile, hardness and wear properties of the NR/SBR blends with the increment of NR percentages were greatly enhanced. The study also indicated that filler materials affect on the physical and mechanical properties of the blends.

Evolution of Particle Morphology During Polymerisation of High Impact Polypropylene

The particle morphology of impact polypropylene was examined experimentally in order to understand how the rubber phase produced in the second step of the polymerisation is distributed inside the growing polymer particles, and how the quantity of rubber produced influences the overall morphology of the final product. It was found that the rubber can pool on the surface of the growing particles, but that this pooling is not uniform. In addition, it was observed that the rubber phase does not flow out of the large pore openings on the surface of the particles. A possible mechanism for the distribution of rubber was proposed. #An earlier version of this paper was presented at ECOREP II, 2nd European Conference on Reaction Engineering of Polyolefins, Lyon, France, July 1–4, 2002.

Behavior of furnace black types in cis polybutadiene rubber (CBR) compounds and changes in the rheological properties of SBR-1502/CBR-1203 types of rubber compounds

Six different compounds were prepared by using CBR-1203 type of cis polybutadiene rubber and SBR-1502 type of styrene butadiene rubber in different proportions, keeping fixed the total rubber quantity specified in the standard testing recipe, and the rheological properties of the subject compounds were measured. Also, 27 different compounds were prepared with CBR-1203 type of synthetic rubber using furnace blacks having different structures (DBP absorption value) and surface areas (iodine adsorption value), classed as N-220, N-330, N-550, N-660 by ASTM, and furnace blacks having different structures but similar surface areas, classed N-326, N-330, N-347, by changing the standard testing recipe proportions. Physical and rheological tests were carried out and the results compared.

The Major Protein of Guayule Rubber Particles Is a Cytochrome P450: CHARACTERIZATION BASED ON cDNA CLONING AND SPECTROSCOPIC ANALYSIS OF THE SOLUBILIZED ENZYME AND ITS REACTION PRODUCTS

Guayule plants accumulate large quantities of rubber within parenchyma cells of their stembark tissues. This rubber is packed within discrete organelles called rubber particles composed primarily of a lipophilic, cis-polyisoprene core, small amounts of lipids, and several proteins, the most abundant of which is the M(r) 53,000 rubber particle protein (RPP). We have cloned and sequenced a full-length cDNA for RPP and show that it has 65% amino acid identity and 85% similarity to a cytochrome P450 known as allene oxide synthase (AOS), recently identified from flaxseed. RPP contains the same unusual heme-binding region and possesses a similar defective I-helix region as AOS, suggesting an equivalent biochemical function. Spectral analysis of solubilized RPP verifies it as a P450, and enzymatic assays reveal that it also metabolizes 13(S)-hydroperoxy-(9Z,11E)-octadecadienoic acid into the expected ketol fatty acids at rates comparable with flaxseed AOS. RPP is unusual in that it lacks the amino-terminal membrane anchor and the established organelle targeting sequences found on other conventional P450s. Together, these factors place RPP in the CYP74 family of P450s and establish it as the first P450 localized in rubber particles and the first eukaryotic P450 to be identified outside endoplasmic reticulum, mitochondria, or plastids.