Table 1 - uploaded by Andrew V. Chapman
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There is increasing pressure for products to be manufactured in part or entirely from renewable materials and for the energy consumption over the life cycle of products to be minimised. In the case of products based on rubber, NR and polymers based on NR can help to meet these challenges. With its very uniform microstructure, NR has very low hyster...
Contexts in source publication
Context 1
... energy inputs for production of natural rubber are given in Table 1 11 . The total energy input, 15-16 MJ/kg, contrasts with that required for the synthetic rubbers, typically 100 MJ/kg, which equates to an emission of about 3 kg carbon dioxide per kg of rubber. ...
Context 2
... recovery behaviour, together with low fogging, good property retention after heat ageing at 135°C (Table 8) and good environmental resistance, indicates that NRTPV is suitable for a range of product areas, including automotive sealing applications and windscreen wipers. As shown in Tables 9-11, TPENR provides good general physical properties, combined with excellent heat and oil resistance. Indeed, the retention of properties at high temperatures is rather better than might be expected from a TPV based on an unsaturated elastomer. ...
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Citations
... It was originally shown that the fracture toughness of epoxy can be increased by adding a dispersed rubber phase to glassy, highly cross-linked epoxy resins, which are widely recognized as brittle thermosets and need to be toughened for a number of applications. Due to the increased benefit of using renewable raw materials for the investment of current high plastic systems, NR is a material of choice of identified rubbers [5]. NR is made up of long polymeric chains with a high degree of flexibility and mobility that are linked together to form a network structure [6]. ...
... Based on the findings of a previous study, the optimum sodium bicarbonate loading, 15 phr, was chosen as the loading that would result in the highest possible porosity content. As a toughening agent, natural rubber in various volumes (5,10,15,20, and 25 vol.%) was utilized. A magnetic stirrer was used to combine the epoxy (95 vol.%) and NR (5 vol.%) in a total of 250 ml of solution until the rubber was completely dissolved. ...
A range of pore-sized epoxy foams toughened by natural rubber (NR) were created using sodium bicarbonate as a chemical foaming agent. It was found that the right formulation would guarantee good physical properties. To investigate the properties of epoxy foam, we introduced NR as a toughening agent in this study at contents ranging from 5 to 25 vol%. SB was added at an optimal foaming agent rate of 15 phr. It was determined what the viscosity, density, porosity, shape, and pore size of epoxy foam were. Cellular polymers reduce the loss of mechanical strength and polymer weight through pores in the foam.
... ENR has polar functional groups (epoxide groups) on the backbone, which give it a higher degree of polarity compared to pure NR or BR and ENR tend to interacts with hydroxyl groups on the lignin surfaces (Chapman, 2007). It was found that the performance of the lignin-filled ENR compound was subsequently improved . ...
This study reports the effect of two different types of compatibilizer, namely epoxidized natural rubber with 50 mol% of epoxide group (ENR-50) and liquid butadiene rubber (LBR-352) for carbon black/lignin-filled natural rubber/polybutadiene rubber (NR/BR) composites in the range of 5–15 parts per hundred rubber (phr). The presence of ENR at concentrations up to 10 phr in carbon black/lignin-filled NR/BR composites reduced cure and scorch time by 33.7% and 21.1% respectively, compared to composites without ENR. This contributed to a better dispersion of the filler and an increase of the 300% modulus by 28.1%. Scanning electron microscopy results (SEM) showed better interaction between carbon black/lignin-filled NR/BR with ENR. Meanwhile, the composites with LBR showed the lowest filler-filler interaction, indicated by a decrease in storage modulus with an increase in strain in the filled compound i.e., Payne effect. Moreover, the utilization of LBR was increased by 168.8% compared to 18.3% with the addition of ENR. It can be concluded that the presence of ENR can enhance the mechanical, flexibility and dynamical properties, while the use of LBR can improve the process-ability and flexibility of rubber composites.
... The photosynthetic rate of this tree is 11 μmol m À2 s À1 and this value is relatively high when compared to that of other species. The values for other species range from 5 to 13 μmol m À2 s À1 (Chapman 2007). The carbon sequestration ability of a 30-year-old rubber tree is estimated to be around 270 t ha À1 . ...
Euphorbiaceae, the spurge family has 6745 species in 218 genera. Though they are cosmopolitan in occurrence, they are distributed primarily in the tropics and are xerophytes. Many of these species carry milky latex, and some are useful as a source of oil or wax. Out of the huge number of species 8 of them are observed to be useful as resource in biodiesel production and hence dealt in this chapter. Out of the above, 5 (Aleurites moluccanus, Croton megalocarpus, Hevea brasiliensis, Jatropha curcas and Vernicia montana) belong to a single subfamily Crotonoideae. Other 3 species belong to Euphorbioideae (Euphorbia lathyris and Triadica sebifera) and Acalyphoideae (Ricinus communis).
... This is due to the different in thermal linear growth between rubber and mould that affect the shrinkage rate during the curing process and result in porosity. Furthermore, product that manufacture by NR/EPDM usually causes an ozone cracking on the surface of the product and directly reduce the shelf life of that product [7][8][9][10]. Figure 1 shows an example of distortion and shrinkage on rubber component due to incorrect pressure and temperature. ...
Natural Rubber/Ethylene Propylene Diene Monomer (NR/EPDM) elastomeric has gaining popularity in the automotive industry owing to the fact in term of sustainability. With extensive studies and an increasing number of applications for future advancement, the need for an accurate and reliable guide in processing this type of elastomer has increased enormously. The present work deals with the study of compression moulding parameters (i.e. temperature, pressure, heating time and pressure time) and its effects against NR/EPDM elastomeric mechanical properties (i.e. ultimate tensile strength (UTS), cross-link density and eccentricity error) aim on establishing optimized processing parameters setup. The optimizations are achieved through the Response Surface Methodology (RSM) and mathematical model for each response is developed to access the relationship between the parameters. Adequacy of models is analysed statistically using analysis of variance (ANOVA) in the determination of significant input variables and possible interactions. Lastly, multi objectives optimization is performed through numerical optimization and predicted results are validated. Strong agreement between experimental and the selected solution are found in between 93% and 96%, thus validating the solution as an optimal run condition. The findings suggest that temperature and heating time is the main factor affecting ultimate tensile strength, whereas for cross-link density there is only one significant parameter which is temperature. UTS and cross-link density decrease with the increases of the temperature and heating time due to the degradation (temperature too high for NR/EPDM working temperature). Therefore, it is recommended to start the process below the NR/EPDM degradation point to avoid the scissoring rubber take place and subsequently improving the mechanical properties
... Indeed, NR is the selected rubber for demanding applications, for instance those in tire compounds (for cars, heavy trucks, and airplanes), anti-seismic base isolators, and anti-vibrating mounting pads. Moreover, NR is produced with a far lower energy input with respect to synthetic rubber: 15-16 MJ/kg versus a typical value of 100 MJ/kg [4]. It is also worth mentioning the efficient carbon sequestration performed by the Hevea tree: the photosynthetic rate of Hevea leaves is of about 11 µmol/m 2 ·s versus a value of 5-13 µmol/m 2 ·s in other trees [18]. ...
... The stress-strain curves were converted into the Mooney-Rivlin plots, shown in Figure 7, where the reduced stress given by Equation (4) σ* (σ* = σ/(α 2 − α −1 )) (4) was plotted versus the reciprocal of the extension ratio α. ...
... The stress-strain curves were converted into the Mooney−Rivlin plots, shown in Figure 7, where the reduced stress given by Equation (4) σ* (σ*=σ/(α 2 -α − 1 )) (4) was plotted versus the reciprocal of the extension ratio α. The Mooney Rivlin plot reveals the stress upturn, which is considered to be due either to the entanglements which behave as effective crosslinking points at higher elongations. ...
The ultimate properties and resistance to fracture of nanocomposites based on poly(1,4-cis-isoprene) from Hevea Brasiliensis (natural rubber, NR) and a high surface area nanosized graphite (HSAG) were improved by using HSAG functionalized with 2-(2,5-dimethyl-1H-pyrrol-1-yl)propane-1,3-diol (serinol pyrrole) (HSAG-SP). The functionalization reaction occurred through a domino process, by simply mixing HSAG and serinol pyrrole and heating at 180 °C. The polarity of HSAG-SP allowed its dispersion in NR latex and the isolation of NR/HSAG-SP masterbatches via coagulation. Nanocomposites, based either on pristine HSAG or on HSAG-SP, were prepared through traditional melt blending and cured with a sulphur-based system. The samples containing HSAG-SP revealed ultimate dispersion of the graphitic filler with smaller aggregates and higher amounts of few layers stacks and isolated layers, as revealed by transmission electron microscopy. With HSAG-SP, better stress and elongation at break and higher fracture resistance were obtained. Indeed, in the case of HSAG-SP-based composites, fracture occurred at larger deformation and with higher values of load and, at the highest filler content (24 phr), deviation of fracture propagation was observed. These results have been obtained with a moderate functionalization of the graphene layers (about 5%) and normal lab facilities. This work reveals a simple and scalable way to prepare tougher NR-based nanocomposites and indicates that the dispersion of a graphitic material in a rubber matrix can be improved without using an extra-amount of mechanical energy, just by modifying the chemical nature of the graphitic material through a sustainable process, avoiding the traditional complex approach, which implies oxidation to graphite oxide and subsequent partial reduction.
... The vulcanizate properties of silica-filled ENR are comparable to carbon black compound at similar loading and are superior to a silica-filled NR without silane coupling agent (Table 1) [26,29]. A comparison of physical properties of ENR-25-silica tread compound without coupling agent to sSBR/ BR-silica compound is shown in Table 2 [30]. In contrast with sSBR/BR, the ENR compound shows better reinforcement with silica without coupling agent. ...
... ENR-silica compounds have higher total bound rubber content than NR/ BR-CB compound. Chapman 18 have reported the high level of ENR-25 is bound to silica (>1 g ENR per g of silica) and ENR-25 binds more strongly to silica than NR based on volume swelling (Vr). With ammonia treatment, the chemically bound rubber content of ENR-silica compounds are still high and only showing very slight reduction which is due to breaking of hydrogen bonding between ENR and silica. ...
Modification of natural rubber via epoxidation process increases its compatibility with highly polar filler like silica. In this work, epoxidized natural rubber (ENR) reinforced with silica compound is evaluated for truck tire tread compound. The theological, physical and dynamic properties as well as the bound rubber content of ENR-silica tread compound are discussed. The results show that ENR-silica compound has high chemically bound rubber indicating the good interaction and bonding between rubber and silica. In addition, the dynamic test shows the ENR-silica vulcanizate exhibit higher Tan delta at 0 degrees C and lower tan delta at 60 degrees C as compared to conventional natural rubber-carbon black vulcanizate, which gives indication of higher wet grip and lower rolling resistance of the ENR vulcanizate. The use of ENR reinforced with silica filler in tread compound is a unique combination that offers renewable material for greener tire application.
... The aim of this study was to determine the effects of ENR contents and OMMT on the gas barrier, and tensile and thermal properties of nanocomposite blend films. Furthermore, application of ENR as one of the environmental friendly resources [35], bio-based material and susceptibility for living organisms [26] and low cost [36] will be of assistance in terms of cost reduction and biodegradable film. The blends with various ENR contents (0-10 wt%) are melt-compounded and blown to films. ...
The effects of organo-modified montmorillonite (OMMT) nanoclay and epoxidized natural rubber (ENR) content on the gas barrier, tensile, and the thermal properties of nanocomposite films based on low-density polyethylene (LDPE) are investigated. Linear low-density polyethylene-grafted maleic anhydride (LLDPE-g-MA) is used as a compatibilizer to obtain better dispersion of the nanoclay in the blends. The blends, with various amounts of ENR (0–10) wt%, are melt-compounded and extruded using a blown film extrusion single screw. The tensile properties of films are studied in machine direction (MD). The gas permeability of films is studied via constant pressure and a soap bubble flow meter. The melting and crystallization behaviors of films are examined via differential scanning calorimetry (DSC). Chemical interactions of composite blends are examined via Fourier transform infrared (FTIR) spectroscopy. An addition of 6 wt% nanoclay improved the tensile modulus by about 11 %. It further reduced the oxygen permeability by about 83 %. Although introducing OMMT decreased the percentage of crystallinity (X
C), the presence of LLDPE-g-MA in the nanocomposite enhanced the property due to better intercalation between the phases. Incorporation of ENR caused an increase in the Young’s modulus for compatibilized nanocomposite systems, attributed to an interaction among clay, compatibilizer, and ENR, and cross-linking effects of ENR molecules. However, ENR decreased the permeability of the film due to the ability of amorphous regions to form crystallized structures during the blown process, and cross-linking effects of ENR. In addition, ENR reduced the X
C of nanocomposites due to an interference that exists in the form of ENR molecular incorporation. The FTIR spectra showed that the maleic anhydride group in LLDPE-g-MA reacted in situ with the epoxy groups of ENR, which was an evidence of grafting reaction.
... Until now, various biodegradable or nonbiodegradable polymers, such as poly (butylene adipate-co-terephthalate) [8], polycaprolactone [9], polyhydroxyalkanoate copolymers [10], poly(butylene succinate) [11], hyperbranched polymers [12], poly(ether) urethane elastomer [13], polyamide elastomer [14] , soybean oil derivatives [15] , thermoplastic polyolefin elas- tomer [16], rubbers [17], acrylonitrile-butadienestyrene copolymer [18], polyethylene [19], poly(ethylene-glycidyl methacrylate) [20] and glycidyl methacrylate-grafted poly-(ethylene-octene) [21], have been used to blend with PLA, acting as toughening components. Natural rubber (NR), known as a " green " and renewable material from rubber trees, is a suitable candidate to be used as an impact modifier for PLA based on the concept of biobased materials [22]. Recently, Bitinis et al. [7] reported a series of works on PLA/NR blends, in which 10 wt% of NR improved the brittleness of PLA and increased the elongation at break from 5% to 200%. ...
... Only 30% of the ingredients of those tires are petrol derivatives. They contain epoxidized natural rubber (ENR) and silica in the tread; the mineral oil and the synthetic fibers have been replaced by vegetable oil and vegetable fibers, respectively [7]. Thus, the new eco-tires are less dependent on petrol sources. ...
The aim of this study is to investigate the zinc resinate's influence on the rheological, vulcanization, mechanical and dynamic properties of the composites based on silica filled natural rubber, containing bi-functional organosilanes in the presence or absence of zinc oxide. The results obtained demonstrate that the presence of zinc resinate leads to considerable decrease of Mooney viscosity of the rubber compounds investigated. The mixture of zinc oxide and zinc resinate has a strong anti-reversion effect. The reversion absence found in the cure curves results in retaining the mechanical properties of the vulcanizate obtained regardless of the curing duration.
