Browsing by Author "Egodage, SM"

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item: Conference-Extended-Abstract
Banana fibre extraction and use as a filler in natural rubber compounds
(2011) Lokubalasooriya, SU; Egodage, SM; Premachandra, BAJK
In this study banana fibres were extracted using three processes and advantages/drawbacks are discussed according to yield, extraction time, quality and properties of banana fibres obtained by each process. Three parts of banana tree (i.e. stem, mid rib and leaves) of two different types of banana trees (i.e. Seeni hesel and Aanamalu) have been analyzed. Two series of filled natural rubber compounds were prepared by changing flier loading from 0-50 phr using banana fibre and carbon black as fillers and physical properties were examined. Hardness increased with both banana fibre and carbon black loading. However, tensile strength decreased with banana fibre loading, while they increased with carbon black loading. These results suggested that the banana fibre could not be added as a reinforcing filler to replace carbon black in rubber compounds. However it can be added to rubber compounds as a diluent filler.
item: Thesis-Full-text
Design of plastic rim for industrial and commercial light vehicles using modeling and simulation tools
Gunapala, DL; Egodage, SM
The present research was devoted to designing a plastic rim for industrial and commercial light vehicles using modeling and simulation tools. The main objective of the design project was to design a rim structure that would be capable of sustaining the required load and performing under provided conditions. In order to select a suitable thermoplastic composite a series of plastics was experimented. The selection of material was based on several factors, including mechanical strength under dynamic load, resistance to prolonged action of elevated temperatures and ability to be molded with conventional techniques. The materials which were considered for the design included Polyamide 6, Polyamide 6 with 50% long glass fibers, Polyamide 6 with 50% short glass fibers and Polyamide 6 with 30% short glass fibers, out of which Polyamide 6 with 30% short glass fibers was selected due to it being less brittle, that aided the material to withstand service and accidental impact. Another criterion that supported selected material was associated with its ability to be injection molded with conventional type injection molding techniques. Four models were developed based on general plastic product design standards. Each model was simulated in order to identify areas of potential failure. After that model was optimized by changing its structural arrangements so as the stresses in the potential failure areas were reduced. Next step in modification and optimization ofthe model was done for product mold-ability. The model which comprised a solid body of rim portion with a center bore configured to receive axle hub, an inner band, a circumferentially extended outer band that margined the rim portion, a nave ring that extended outwardly and radially ofsaid center bore wherein a plurality of holes were circularly positioned that were configured to receive bolts, a plurality of ribs extending outwardly and radially at right angles from the nave ring up to the outer band were positioned both sides ofthe rim configured to improve flexural rigidity of the structure was accepted for fabrication by means ofreinforcement of hub hole area with metal plate. A manufacturing method of plastic rim was selected based on the material processbility, manufacturing cost and efficiency for serial manufacturing and commercialization. Prototype Injection mold was manufactured using cheap and easy to machined steel P-20. Produced standard mold was modified to improve ventilation and to facilitate flow of the plastic melt through the flow path of the injection mold from machine nozzle to cavity The successful prototypes and destructive tests carried out affirmed suitability of the Solidwork Design package and Solidwork Simulation Package for designing, manufacturing and prediction of load bearing capability of the plastic rim. The application of Solidwork Simulation Package during designing stage lead to reduced implementation cost and reduced reproduction numbers of prototypes to evaluate product suitability, thereby making implementation ofthe final product efficient. The main advantages of using plastic composite material for automotive rims included energy efficiency and easy maintenance due to lower weight
item: Conference-Full-text
Development of a competitive thermoplastic vulcanizate roofing sheet from natural rubber and high-density polyethylene
(IEEE, 2021-07) Wickramaarachchi, WH; Walpalage, S; Egodage, SM; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
Clay, asbestos, plastic and metal are commonly used as roofing materials in Sri Lanka and every material has its inherent drawbacks. Asbestos sheets are going to be banned due to health hazards. Thermoplastic Vulcanizate (TPV), a kind of polymer blends, gives combined properties of their individual polymers. Therefore, this study was aimed to develop a health hazard-free and economically viable roofing material from TPV to be competitive with the existing roofing materials. TPV pellets of 20/80 Natural rubber (NR)/High-Density Polyethylene (HDPE) in two different formulas were prepared using a twin-screw extruder. Roofing sheets having size of 40 cm × 40 cm × 0.6 cm were moulded using TPV pellets. Properties were tested according to the ASTM standards for Poly-Vinyl Chloride (PVC) roofing sheet and the certificates for properties of the PVC roofing sheets available in Sri Lanka. Properties of the two TPV sheets prepared were compared with those of the PVC sheets. TPV sheet having 1 phr of dicumyl peroxide and 50 phr of barium sulphate showed the optimum properties and were comparable with impact strength, elongation at break, density and thermal conductivity of PVC roofing. The developed TPV sheet is cost competitive and suitable for the high-class customer segment.
item: Conference-Abstract
The development of rubber-thermoplastic blends from ground tyre rubber and waste polypropylene
(2006) Egodage, SM; Harper, JF; Walpalage, S
Rubber-thermoplastic blends are regarded as economical alternatives to the synthesis of new polymers with moderate characteristics and the market for such materials has grown dramatically because of the ability to recycle and process them in conventional thermoplastic machinery. Polymer blending entails the combination of the attractive features of several materials to improve the deficient characteristics of anyone of them, with a reduction in the price of the end product. Blending of polymer waste further reduces the price whilst helping to solve the waste disposal problem that industry currently faces. Rubber rich blends produce a soft thermoplastic elastomer while plastic rich blends produce a rubber toughened thermoplastic. However, literature reveals that the additions of rubber to a thermoplastic matrix result in a significant overall deterioration in mechanical properties.
item: SRC-Report
The Development of the extraction process for banana fibers and the use of banana fibers in dry rubber products
Egodage, SM
The use of natural fibers as fillers in the rubber industry is a new trend. Banana fibres has been incorporated into phenol formaldehyde and polyester resins as a reinforcing material. However, the use of banana fiber in dry rubber formulations is novel. The main objectives were to study the banana fibre extraction processes, to identify the most suitable process, and to examine the usage of banana fibre as potential filler in natural rubber (NR) compounds by characterizing the compounds chemically, mechanically and physically. In this study, banana fibres were extracted using three methods namely water retting, chemical retting and mechanical extraction. Extraction time, yield and tensile properties of fibres for different extraction processes were studied to identify the best suited method. The dried ground fibres in a range of 0.01 - 1.2 mm prepared and incorporated into a natural rubber compound at fibre loading from 0 to 50 phr at 10 phr intervals. Coupling agent, a two component system of phenol formaldehyde and hexamethylene tetra amine was also used. Mechanical extraction was identified as the most suitable process for fibre extraction. Banana fibres were composed of high cellulose content, which is favorable in order to enhance its reinforcement effect in NR compounds when added with the coupling agent. Cure time and scorch time decreased with the banana fibre loading and further with the coupling agent. Hardness and modulus increased with the fibre loading, while tensile properties decreased. With incorporation of the coupling agent, hardness and modulus further increased, tensile strength, elongation at break and tear strength increased at every fibre loading by up to 40%, 200% and 22% respectively. Banana fibre alone behaved as diluent filler, but banana fibre with the coupling agent showed reinforcement to the rubber compound
item: Article-Abstract
The Effect of a coupling agent on mechanical properties of coconut shell powder filled natural rubber composites
Iresha, RDH; Egodage, SM
Coconut Shell Powder (CSP) is an abundant lignocellulosiccomponentobtained from Coconut shells, which can be used as natural filler for rubbers and plastics to enhance their mechanical properties and biodegradability. Lignocellulosic fillers present significant properties compared to conventional mineral fillers, which are commonly used with polymers like CaCO3, silica, talc mica, etc. Further, CSP is, biodegradable, renewable, inexpensive, ecofriendly, lower in density, minimal health hazards and less abrasion to processing machinery compared to silica. Conjugating these properties with specific properties of commercial polymers could be a great value addition to both materials. CSP is incorporated into natural rubber (NR) as filler, with and without modifications with alkali solution. However, no significant enhancement in mechanical properties was exhibited.Therefore, the main objective of this study was to evaluate the effect of two coupling agents namely, Silane and Maleic Acid on physico-mechanical properties of CSP filled NR composites, in order to uplift CSP as natural filler for NR. In this study, five different NR compounds were prepared by varying CSP loading from 10phr to 50 phrin 10 phr intervals. A series of silica filled NR composites was prepared for comparison. Properties of CSP filled NR composites was inferior compared to those of silica filled NR composites. However, composites with coupling agents showed better properties compared to those prepared without a coupling agent.
item: Article-Abstract
The Effect of Banana fibre loading on physical mechanical properties of natural rubber vulcanizates
Egodage, SM; Lokubalasuriya, SU; Premachandra, BAJK
The use of natural fibres as fillers in the rubber industry is a new trend. Banana fibre has been incorporated into phenol formaldehyde and polyester resins as a reinforcing material However, the use of banana fibre in dry rubber formulations is novel. The objective of the prese study is to investigate the effect of fibre loading on rheological properties and the physico-mechanical properties of a dry rubber compound with the aim of using banana fibre as potential filler for natural rubber vulcanizates. In this study, ground fibres in a range of 0.01 - 1.2 mm were prepared and incorporated into a natural rubber compound at fibre loading from 0 to 50 phr at 10 phr intervals Coupling agent, a two component system of phenol formaldehyde and hexamethylene tetra amine was also used. Hardness and modulus increased with the banana fibre loading while tensile properties decreased. With incorporation of the coupling agent, hardness and modulus further increased, tensile strength, elongation at break and tear strength increased at every fibre loading by up to 40%, 200% and 22% respectively. Banana fibre alone behaved as a diluent filler, but banana fibre with the coupling agent showed a reinforcement to the rubber compound.
item: Article-Abstract
Effect of blend ratio on properties of natural rubber/low density polyethylene blends
Sampath, WDM; Egodage, SM; Edirisinghe, DG
Thermoplastic natural rubber (TPNR) those produced by blending of thermoplastics and natural rubber using traditional internal mixers and plastic extruders, are becoming increasingly accepted in the global polymer market. Natural rubber (NR)/low density polyethylene (LDPE) blend is used as a TPNR in the manufacture of rubber based articles. These blends can best be appreciated as high impact resistant engineering materials and The main objective of this study was to investigate the effect of blend ratio on physical, chemical and mechanical properties of NR/LDPE blends. In this study, a series of simple blends was formulated by varying LDPE loading from 10 to 90 by wt. at 20% intervals. The blends were prepared using a Brabender Plasticorder by melt mixing at a temperature of 130 °C, and at a rotor speed of 60 rpm. Minimum torque of melt blending was investigated by a moving die rheometer while glass-transition temperature (Tg) of blends were measured by differential scanning calorimetry. Swelling behaviour studied by sol/gel analysis using toluene as the solvent, according to ISO standard. Physicomechanical properties were determined according to ISO standards. Minimum torque, which is an indication of the processability and of stock viscosity, decreased with increase in LDPE loading. Tear strength, tensile strength and hardness increased with increase in LDPE loading while elongation at break decreased. Glass-transition temperature, Tg of NR phase of the blends slightly varied with LDPE loading. Solvent resistance increased with increase in LDPE loading. These results indicate a phase change after 30 % by wt. of LDPE loading. Further, the results reveal that the blends with different properties required for different applications could be obtained by varying the blend ratio.
item: Article-Abstract
The effect of coupling agent and mixing methods on properties of natural rubber and low density polyethylene blends
Sampath, WDM; Egodage, SM; Edirisinghe, DG
Coupling agents are molecular bridges at the interface between two substrates, an inorganic filler an organic polymer matrix. When incorporated into polymer systems, they often promote adhesio) improve dispersion, improve impact strength and thus reduce embrittlement. The practical Utility polymer blend is determined by the compatibility of component polymers, which is considered asjtifundamental property. It has been observed that majority of rubber-thermoplastic blends, in 1 natural rubber (NR) and low density polyethylene (LDPE) blends are incompatible thus -prinferior properties. Thermoplastic molecules can be reshaped with heat and pressure since they cross-link. This provides them the property of being easily fabricated by conventional plastics pti^ techniques such as extrusion, injection molding and blow molding. The main of this s investigate the effects of titanate base coupling agent and mixing methods on NR and L composites in terms of their physic-mechanical, chemical properties and phase morphology of 50/50 NR/LDPE filled CaCo3 composites were prepared by using internal mixer (brabend and 60 rpm for 14 minutes. Coupling agent was incorporated into polymer matrix
item: Article-Abstract
Effect of maleimide curing on mechanical properties of ground tyre rubber/waste polypropylene blends
Egodage, SM; Harper, JF; Walpalage, S
Blends of ground tyre rubber and waste polypropylene with a maleimide curing system (50: 50blends of ground tyre rubber/waste polypropylene) were prepared in a Haake Rheocord Polylab System, at 180°C and 90 rev min-1 for 5 min. The curing agent and the activator used were N,N'- meta-phenylene dimaleimide (HVA-2) and di(tert-butylperoxyisopropyl) benzene (DTBPIB) respectively. The HVA-2 level varied from a to 5 parts per hundred parts (pphp), while the DTBPIB level varied from a to 1 pphp. Melt viscosity, tensile strength and elongation at break showed an increase with HVA-2 content, while the impact energy showed an optimum at 3 pphp level. The addition of the DTBPIB increased melt viscosity further and produced a homogeneous phase morphology of the blends. Impact energy improved with the DTBPIB level, while elongation at break and tensile strength showed an optimum at 0·6 pphp. Swelling behaviour and gel/sol from the boiled xylene extractions were studied, and the results obtained were correlated with the impact and tensile properties.
item: Conference-Abstract
Evaluation of use of Tea waste Bio-Char (TBC) as alternative filler for Natural Rubber (NR)
Iresha, H; Egodage, SM; Weerakoon, CS; Muthukumarana, PU; Hewamallikage, YR
Tea waste generated in tea factories, which is the portion that cannot be marketed, is an abundant natural waste in Sri Lanka. Some of the tea manufacturers have converted this bulk waste into its bio-char by using pyrolysis in addition of using for composting and soil conditioning. Considering the high carbon content shown in bio-char, and its nature of biodegradability, renewability, high moisture, smells, toxins and electrosmogs absorption ability, and low thermal conductivity, powdered tea waste bio-char (TBC) can be used as filler in rubbers and will tend to use in a wide spectrum of applications. Bio-char obtained from different natural sources have been researching for different applications especially as filler for different rubbers. However, using TBC in NR as filler is novel. This study adduces the results of proximate analysis of TBC, cure properties, and mechanical properties of TBC/NR composites such as tensile properties, tear strength, hardness, with respect to TBC particle size (125 µm< X < 250 µm and 125 µm X)and loadings from 10 phr to 50 phr at 10 phr intervals. The properties were compared with those of NR composites prepared with carbon black conventional filler (N330). Microscopic images of cross sections of composites were used in order to explain the trends in properties obtained.
item: Article-Abstract
Ground tyre rubber/waste polypropylene blends - effect of composition on mechanical properties
Egodage, SM; Harper, JF; Walpalage, S
Ground tyre rubber (GTR) was blended with waste polypropylene (WPP) in nine different compositions to prepare GTRIWPP blends. The blends were prepared in a Haake Rheocord PolyLab system at a temperature of 180 °C and a rotor speed of 30 r/min for 8 min. The processing characteristics of the blends showed an increase in steady-state mixing torque with an increase in GTR content, suggesting an increased difficulty in processability at GTR loadings above 30 wt.%. Morphological observations of the blends showed two-phase systems. The GTR was dispersed in a continuous WPP matrix in blends containing up to 60 wt.% GTR, and the size of the dispersed GTR agglomerates increased with GTR content. At 70 wt.%, the GTR dispersed phase changed to a continuous phase. Tensilestrength, modulus, and tear resistance decreased with GTR content, while the elongation at break and the impact failure energy increased. All these properties remained relatively unchanged at low GTR contents, suggesting that a critical GTR level is required to obtain rubber-like properties in a simple rubber-thermoplastic blend.
item: Conference-Abstract
Improvement of physico-mechanical properties of Calcium Carbonate filled Natural Nubber and Low Density Polyethylene blends with titanate coupling agent
Sampath, WDEM; Edirisinghe, DG; Egodage, SM
Nonblack particulate fillers most used with thermoplastic and rubber are calcium carbonate, silica, talc and alumina hydrates. The main characteristics, which control the effectiveness and the dispersion of filler in the polymer, are structure, surface area and chemical activity of filler. The mechanical behavior of rubber-thermoplastic blends depends greatly on interactions and compatibility that develop between the two polymers and the filler. The main objective of this study is to improve physico-mechanical properties of calcium carbonate (CaCO3) filled natural rubber (NR) and low density polyethylene (LDPE) blends using a titanate coupling agent. Two series of NR/LDPE blends, with and without titanate coupling agent, were prepared by varying LDPE loading from 10% to 90% at 10% intervals. 20 parts by weight of CaCO3 per 100 parts of combined polymer was incorporated into every blend composition. The blends were prepared using a Brabender plasticorder by melt mixing at a temperature of 130 oC, and at a rotor speed of 60 rpm. Physico-mechanical properties such as tensile properties, hardness, tear strength and morphology of the blends were studied. These properties were determined according to ISO standards. Morphology of the tensile fracture surface of blends was observed using a transmitted light microscopy. Tensile strength, tear strength and hardness of NR/LDPE blends increase with increase in LDPE loading while elongation at break decreases. NR/LDPE blends with titanate coupling agent exhibited enhanced properties at every LDPE loading. NR/LDPE blends having 30% of LDPE loading showed highest tensile strength. In this blend, NR was dispersed in LDPE matrix with good adhesion between NR and LDPE.
item: Conference-Full-text
Improvement of Physico-Mechanical Properties of Calcium Carbonate filled Natural Nubber and Low Density Polyethylene Blends with Titanate Coupling Agent
(2015-08-14) Sampath, WDM; Edirisinghe, DG; Egodage, SM
Nonblack particulate fillers most used with thermoplastic and rubber are calcium carbonate, silica, talc and alumina hydrates. The main characteristics, which control the effectiveness and the dispersion of filler in the polymer, are structure, surface area and chemical activity of filler. The mechanical behavior of rubber-thermoplastic blends depends greatly on interactions and compatibility that develop between the two polymers and the filler. The main objective of this study is to improve physico-mechanical properties of calcium carbonate (CaCO3) filled natural rubber (NR) and low density polyethylene (LDPE) blends using a titanate coupling agent. Two series of NR/LDPE blends, with and without titanate coupling agent, were prepared by varying LDPE loading from 10% to 90% at 10% intervals. 20 parts by weight of CaCO3 per 100 parts of combined polymer was incorporated into every blend composition. The blends were prepared using a Brabender plasticorder by melt mixing at a temperature of 130 oC, and at a rotor speed of 60 rpm. Physico-mechanical properties such as tensile properties, hardness, tear strength and morphology of the blends were studied. These properties were determined according to ISO standards. Morphology of the tensile fracture surface of blends was observed using a transmitted light microscopy. Tensile strength, tear strength and hardness of NR/LDPE blends increase with increase in LDPE loading while elongation at break decreases. NR/LDPE blends with titanate coupling agent exhibited enhanced properties at every LDPE loading. NR/LDPE blends having 30% of LDPE loading showed highest tensile strength. In this blend, NR was dispersed in LDPE matrix with good adhesion between NR and LDPE.
item: Conference-Full-text
Powdered corn grain and cornflour on properties of natural rubber latex vulcanizates: effect of filler loading
(IEEE, 2018-05) Jayathilaka, I; Ariyadasa, TU; Egodage, SM; Chathuranga, D
Natural rubber latex (NRL) is used as a basic raw material in manufacturing latex products for household, medical and industrial applications. This widespread use of NRL is caused by the extensive generation of solid waste material. Most of the rubber wastes are disposed of in a landfill, open burning, incineration, open dumping or recycling. As recycling of rubber is not widely practiced due to high cost and insufficient facilities, the accumulation of huge stockpiles of disposed of rubber materials has become huge social and environmental problem. Due to the environmental sustainability matters, use of bio-fillers from renewable resources to reinforce latex compounds has been addressed in this research. In this study, two series of samples were prepared using powdered corn grain and cornflour as fillers and by varying loading from 0 to 50 phr at 10 phr intervals. The effect of these fillers on the physical properties of NRL vulcanizates was investigated. The tensile property, tear strength, density, water absorption and surface morphology were studied. The results indicated that powdered corn grain filled NRL vulcanizates have good mechanical properties compared to cornflour filled vulcanizates. Powdered corn grain loading of 20 phr will be considered as the optimum filler loading to achieve required physical properties.
item: Conference-Abstract
Prospects and challenges for a green hydrogen economy in Sri Lanka
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Karunasena, DI; Himal, SNL; Subasinghe, SADT; Egodage, SM; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
The global energy landscape is experiencing a significant shift towards Green Hydrogen as a sustainable and clean energy paradigm. This research highlights Sri Lanka's potential to invest in this new venture due to its abundant renewable energy capacity. This study evaluated the most suitable hydrogen producing electrolyzer for Sri Lanka and Green Hydrogen production capacity in Sri Lanka against available renewable energy. Further, studies about favourable hydrogen utilization pathways in Sri Lanka. A literature survey was conducted to obtain data related to the AWE, AEM, PEM, and SOE electrolyzer technologies and they were evaluated against capital expenditure, operating expenditure, performance, and technological maturity in selecting an electrolyzer for Sri Lanka. Projected renewable energy capacity for 2030 with peak demand and average demand was considered in the calculation of producible Green Hydrogen amount. For utilization pathways in Sri Lanka, the intensiveness of infrastructure requirement, costeffectiveness, policy and regulations, environmental impact, and safety were analyzed for selected utilization opportunities which included grid balancing, fertilizer production, and fuel blend. Implementing an Alkaline Water Electrolyzer (AWE) was identified as the optimal choice for Green Hydrogen production technology in Sri Lanka and has the capacity to produce 13,500 MWh of Green Hydrogen. It was concluded that produced Green Hydrogen can be utilized as energy storage to mitigate grid imbalance or as a feedstock for fertilizer production. Although use of this technology holds tremendous potential for supporting Sri Lanka's energy needs, an in-depth study should be done towards utilization pathways.
item: Conference-Abstract
Review on development of natural rubber/nanoclay nanocomposites
Jayaraj, KS; Walpalage, S; Egodage, SM
The advantages of nanocomposites containing single silicate layers uniformly dispersed in a polymer matrix were first demonstrated by researchers at Toyota in Japan, who developed nylon-6 nanocomposites and published in 1993. Polymer-nanoclay nanocomposites have attracted the attention of many researchers thereafter due to their outstanding mechanical and barrier properties. This concept is first applied to synthesis of plastics/nanoclay nanocomposites and then expanded to preparation of ubber/nanoclay nanocomposites, since few years later. The various types of synthetic rubbers, such as silicon rubber, nitrile rubber and epoxy rubber, were used to prepare nanocomposites using different techniques, namely, melt intercalation, in situ intercalative polymerization, exfoliationadsorption and template synthesis, etc. Natural rubber (NR) was also used to prepare nanocomposites using the same techniques but with some modifications in the last decade. Now a day’s nanocomposites are widely developed in NR latex industry to achieve required properties with minimum use of clay content. NR/nanoclay nanocomposites exhibit markedly improved properties when compared to pure NR or their traditional composites. Most notable properties are increased tensile properties, gas barrier properties and heat distortion temperature, resistance to small molecule permeation, increase in atomic oxygen resistance and retention of impact strength. Tensile strength and modulus were recorded in current research as enhanced by more than two times or even ten times. It was noticed that obtaining a fully exfoliated structure is not at the desired level. Nanoclay nanocomposites are considered as fully exfoliated when inter gallery distance is greater than 10 nm but it was not achieved in many research work. Establishment of exfoliated structures in nanocomposites prepared in industrial scale is the major challenge that NR industry faces at present. NR/nanoclay nanocomposites produced with existing techniques develop high property fluctuations. Therefore, it is necessary to develop a technique to minimize property fluctuations and to obtain a reliable NR based product. It is predicted by this review that co-coagulation technique is the most promising and potential technique to fulfill the requirements of developing a NR/nanoclay nanocomposite. Use of modified nanoclays like Organoclays will aid to obtain a reliable NR based product.
item: Conference-Full-text
Review On Development Of Natural Rubber/Nanoclay Nanocomposites
(2015-08-03) Jayaraj, KS; Walpalage, S; Egodage, SM
The advantages of nanocomposites containing single silicate layers uniformly dispersed in a polymer matrix were first demonstrated by researchers at Toyota in Japan, who developed nylon-6 nanocomposites and published in 1993. Polymer-nanoclay nanocomposites have attracted the attention of many researchers thereafter due to their outstanding mechanical and barrier properties. This concept is first applied to synthesis of plastics/nanoclay nanocomposites and then expanded to preparation of rubber/nanoclay nanocomposites, since few years later. The various types of synthetic rubbers, such as silicon rubber, nitrile rubber and epoxy rubber, were used to prepare nanocomposites using different techniques, namely, melt intercalation, in situ intercalative polymerization, exfoliationadsorption and template synthesis, etc. Natural rubber (NR) was also used to prepare nanocomposites using the same techniques but with some modifications in the last decade. Now a day’s nanocomposites are widely developed in NR latex industry to achieve required properties with minimum use of clay content. NR/nanoclay nanocomposites exhibit markedly improved properties when compared to pure NR or their traditional composites. Most notable properties are increased tensile properties, gas barrier properties and heat distortion temperature, resistance to small molecule permeation, increase in atomic oxygen resistance and retention of impact strength. Tensile strength and modulus were recorded in current research as enhanced by more than two times or even ten times. It was noticed that obtaining a fully exfoliated structure is not at the desired level. Nanoclay nanocomposites are considered as fully exfoliated when inter gallery distance is greater than 10 nm but it was not achieved in many research work. Establishment of exfoliated structures in nanocomposites prepared in industrial scale is the major challenge that NR industry faces at present. NR/nanoclay nanocomposites produced with existing techniques develop high property fluctuations. Therefore, it is necessary to develop a technique to minimize property fluctuations and to obtain a reliable NR based product. It is predicted by this review that co-coagulation technique is the most promising and potential technique to fulfill the requirements of developing a NR/nanoclay nanocomposite. Use of modified nanoclays like Organoclays will aid to obtain a reliable NR based product.
item: Article-Abstract
Study on the effect of blend composition Physicochemical properties of NR/LLDPE blends for the polymer industry
Gajanayake, GKRP; Egodage, SM
Preparation of polymer blends is a kind of strategy to develop new polymeri materials rather than following new root of synthesis polymers. Further, blending of polymers ^ proven as a cost effective way of achieving polymeric materials with required physicochemical properties. Natural rubber (NR) and Linear low density polyethylene (LLDPE) could be processed using conventional rubber processing equipment. The present study was aimed to investigate the effect of blend composition on physicochemical properties of NR/LLDPE blends. A series of blends was prepared by melt mixing and by varying LLDPE loading from 0 to 80 wt.% at 10 wt% intervals Dicumyl Peroxide and maleic anhydride as the vulcanization agent and the coagent, respectively were incorporated. Rheological properties, thermal properties and physicochemical properties determined according to ISO standards. Cure characteristics, hardness, tear strength, modulus at 300% elongation, and solvent resistance in toluene were increased with LLDPE loading. Tensile properties were improved with the addition of LLDPE up to 50 wt% compared to 100% NR compound and then started to decrease. All the properties were inferior when blends were prepared without the coagent Decrease in glass transition temperature of the LLDPE phase in the blends prepared with the coagent was more prominent and may be due to enhanced interfacial adhesion. By varying the blend ratio, NR/LLDPE blend can be used as a versatile material for appropriate applications in the polymer industry.
item: Conference-Abstract
A techno-economic analysis of the monash ammonia process
(Department of Chemical & Process Engineering University of Moratuwa., 2023-08-17) Gamage, AGKV; Sharanga, KMHG; Subasinghe, SADT; Egodage, SM; Walpalage, S; Gunawardena, S; Narayana, M; Gunasekera, M
Due to the significant carbon footprint associated with conventional ammonia production methods, there has been a growing interest in electrochemical approaches for ammonia production. Although initial yield rates were relatively low in conventional electrochemical methods, a team at Monash University in Australia successfully developed a method capable of producing ammonia with a higher yield at room temperature with 100% faradic efficiency. To assess the potential for scaling up this technology, a techno-economic analysis has been conducted. Assuming a scale of 1 MW for the pilot plant, the NH3 production rate was obtained as 934.64 kg/day. The total capital cost was estimated at $736,913, the daily operating cost at $1192.80, and the daily income at $977.61. Consequently, the plant incurred a daily loss of $215.19. Based on these findings, it can be concluded that the scale-up plant is currently not economically viable. This is primarily attributed to the present high cost of the electrolyzer stack and renewable energy. However, there is a promising trend of decreasing costs for electrolyzers and renewable energy. If this trend continues, there is potential for the scale-up plant to become a viable option in the future.