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Rubber Blends (rubber + blend)

Distribution by Scientific Domains
Polymers and Materials Science93%

Kinds of Rubber Blends

  • natural rubber blend
    		•

    Selected Abstracts

    Processing and Properties of Biobased Blends from Soy Meal and Natural Rubber

    MACROMOLECULAR MATERIALS & ENGINEERING, Issue 10-11 2007
    Qiangxian Wu
    Abstract Vulcanized blends from soy meal and natural rubber were successfully processed through semi-pilot scale extrusion, roll milling and compression-molding. Blends containing about 50 wt.-% of soy meal are elastic and water resistant, compared with the brittle and hydrophilic soy meal. The natural rubber component was well embedded into the soy meal matrix, indicating the existence of an interaction between them. The glass transition temperature of the rubber component in the blends increased due to the existence of this interaction. Calcium sulfate, as a compatibilizer, was a physical cross-linker to the proteins in the soy meal and in the rubber. The morphological analysis of the soy meal and natural rubber blend through scanning electron microscopy revealed a partial compatibility of the blend. The blends containing near 50 wt.-% of inexpensive soy meal have potential for various applications. [source]

    Effect of electron-beam irradiation on poly(vinyl chloride)/epoxidized natural rubber blend: dynamic mechanical analysis

    POLYMER INTERNATIONAL, Issue 5 2001
    Chantara Thevy Ratnam
    Abstract The irradiation-induced crosslinking in 50/50 poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blend was investigated by means of dynamic mechanical analysis. The influence of trimethylolpropane triacrylate on the irradiation-induced crosslinking of PVC/ENR blends was also studied. The enhancement in storage modulus and Tg with irradiation dose indicated the formation of irradiation-induced crosslinks. This is further supported by the decrease in tan ,max and loss modulus peak. The compatibility of the blend was found to be improved upon irradiation. The Fox model was used to provide a further insight into the irradiation-induced compatibility in the blend. Scanning electron microscopy studies on the cryofracture surface morphology of the blends as well as the homopolymer have been undertaken in order to gain more evidence on the irradiation-induced crosslinking. © 2001 Society of Chemical Industry [source]

    A novel approach to the analysis of distributed shear banding in polymer blends

    INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 5 2003
    K. G. W. Pijnenburg
    Abstract The toughness of glassy polymers can be enhanced by blending with rubber particles. The consensus is that this toughening is due to massive plastic deformation of the matrix that takes place once the particles have cavitated. Micromechanical studies of regular stackings of particles in a polymer matrix have provided much insight into the localized plastic flow in blends at the microscale of individual particles (or voids, once cavitated). Even some steps towards macroscopic constitutive models have been made. However, at intermediate length scales (i.e. larger than several particles, but smaller than the scale at which the material may be regarded as homogeneous) the situation is unclear. It is this length scale that becomes important around crack tips, for example, where a thorough understanding of the toughening effect has to be derived from. In this paper, we therefore present a novel approach to the analysis of distributed shear banding in polymer,rubber blends. A coarse-grain description, in which much of the morphology is retained but the local shear banding is idealized into ,shear surfaces', will enable us to analyse ensembles with large numbers of particles. The parameters of this model will be validated with results from detailed cell analyses. Copyright © 2003 John Wiley Sons, Ltd. [source]

    Hydrogenated natural rubber blends: Aspect on thermal stability and oxidative behavior

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2009
    N. Hinchiranan
    Abstract Hydrogenated natural rubber (HNR) prepared from natural rubber (NR) is a new sustainable elastomer with excellent thermal properties. This study reports on the effect of vulcanization system and blend ratio on the thermal and oxidative resistance of HNR/NR vulcanizates. The various HNR/NR ratios vulcanized by peroxide and sulfur donor system exhibited the highest retention of tensile strength after thermal aging due to the formation of zinc-dimethyldithiocarbamate (ZDMDC) which is an efficient antioxidant. The results from thermogravimetric analysis (TGA) indicated that the saturated structure of HNR had higher decomposition temperature and activation energy to enhance the thermal stability of HNR/NR vulcanizates. The initial and maximum decomposition temperatures of NR and HNR phases in vulcanizates were not affected by rubber blend ratio. This suggests that the decomposition pattern of HNR has no influence on another constituent. The increase in HNR content in the blends could retard the ozonolysis resulting in the surface cracking attacked by ozone. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source]

    Properties of solid solutions of poly(ethylene oxide)/epoxidized natural rubber blends and LiClO4

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008
    C. H. Chan
    Abstract Solid solutions of blends of poly(ethylene oxide) (PEO) and epoxidized natural rubber (ENR) comprising 12 wt % of LiClO4 were studied. Two glass transition temperatures, corresponding to the Tgs of the constituents, confirm immiscibility of the polymers over the entire composition range. It turns out that the Tgs of both polymers slightly increase after addition of salt to the blends. This shift is approximately constant over the whole range of blend composition. Accordingly, Tg measurements reveal that the salt dissolves to approximately equal relative amounts in the two phases. The degree of crystallinity of PEO in blends with ENR descends only to a minor extent with ENR content. However, addition of salt leads first to decreasing crystallinity and second this decrease becomes more pronounced with the addition of ENR. It shows that under these experimental conditions the salt content in PEO increases as compared to ENR. As one expects, the rate of isothermal crystallization does not change in blends as long as PEO is in excess. The situation changes again when salt is added. The rate decreases in a certain range of crystallization temperatures when ENR is added, demonstrating that salt is favorably dissolved in PEO. Conductivity was measured in polymers comprising different salt concentrations. A power-law dependence of conductivity on salt concentration was found. It results that the mobility of charge carriers in PEO exceeds that of ENR by five orders of magnitude. Therefore, the conductivity in blends is primarily governed by PEO as long as PEO is in excess. Conductivity measurements reveal again that salt is preferably dissolved in PEO. The distribution coefficient is estimated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

    Adhesion properties of pressure-sensitive adhesives prepared from SMR 10/ENR 25, SMR 10/ENR 50, and ENR 25/ENR 50 blends

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008
    B. T. Poh
    Abstract The adhesion properties, i.e. viscosity, tack, and peel strength of pressure-sensitive adhesives prepared from natural rubber/epoxidized natural rubber blends were investigated using coumarone-indene resin and toluene as the tackifier and solvent respectively. One grade of natural rubber (SMR 10) and two grades of epoxidized natural rubbers (ENR 25 and ENR 50) were used to prepare the rubber blends with blend ratio ranging from 0 to 100%. Coumarone-indene resin content was fixed at 40 parts per hundred parts of rubber (phr) in the adhesive formulation. The viscosity of adhesive was measured by a HAAKE Rotary Viscometer whereas loop tack and peel strength was determined using a Lloyd Adhesion Tester operating at 30 cm/min. Results show that the viscosity of the adhesive passes through a minimum value at 20% blend ratio. For loop tack and peel strength, it indicates a maximum at 60% blend ratio for SMR 10/ENR 25 and SMR 10/ENR 50 systems. However, for ENR 25/ENR 50 blend, maximum value is observed at 80% blend ratio. SMR 10/ENR 25 blend consistently exhibits the best adhesion property in this study, an observation which is attributed to the optimum compatibility between rubbers and wettability of adhesive on the substrate. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

    Effect of ATH content on electrical and aging properties of EVA and silicone rubber blends for high voltage insulator compound

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2007
    M. A. Pradeep
    Abstract The effect of trihydrated alumina (Al2O3, 3H2O) (ATH) filler in ethylene-vinyl acetate copolymer (EVA) and silicone rubber blends was investigated by performing a series of laboratory experiments to simulate different natural aging conditions. Samples with varying ATH content in a 50-50 blend of EVA and polydimethylsiloxane (PDMS) (silicone rubber, MQ) were tested to investigate the tracking resistance, resistance to UV radiation, corona, heat, and water immersion. Changes in surface resistivity, volume resistivity, and hydrophobic characteristics were evaluated for different compounds having ATH content. These exercises were mainly carried out to optimize the filler level. In immersed condition the water absorption increases with ATH content. The recovery of hydrophobicity, after aging by heat, is appreciable at higher ATH levels, than at lower ATH levels. The tracking and erosion resistance decrease as ATH content increases. When compounds containing different ATH content were subjected to corona treatment, the samples with higher ATH levels exhibited better results. All samples changed their color to a darker shade and there was an increase in the hydrophobicity, when subjected to UV radiation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3505,3516, 2007 [source]

    Compatibilization of poly(vinyl chloride) with polyamide and with polyolefin by using poly(lauryllactam- random -caprolactam- block -caprolactone)

    JOURNAL OF VINYL & ADDITIVE TECHNOLOGY, Issue 3 2005
    In Kim
    The compatibilization of various poly(vinyl chloride) (PVC) blends was investigated. The blend systems were PVC-polyamide 12 (PA12), PVC-polypropylene (PP), and PVC-ethylene-propylene-diene rubber (EPDM) with a new compatibilizing agent, random-block terpolymer poly(,-lauryllactam- random -,-caprolactam- block -,-caprolactone) or systems containing these copolymers. The results were compared to those obtained in previous studies using poly(,-lauryllactam- block -,-caprolactone) copolymer. The new block copolymer was specially synthesized by reactive extrusion. Observation by scanning electron microscopy (SEM) revealed that compatibilized blends had a finer morphology than the noncompatibilized blends. Addition of 10 weight percent (wt%) of block copolymer proved to be sufficient to give a significant improvement of the mechanical properties of the immiscible PVC blends at room temperature and at high temperatures that were above the glass transition temperature of PVC. For polyolefins, a three-component compatibilizing system including maleated polypropylene, polyamide 12, and block copolymer was used. It was found that poly(,-lauryllactam- random -,-caprolactam- block -,-caprolactone) was the more efficient compatibilizing agent for the modification of PVC-polyamide 12, PVC-polypropylene, and PVC-ethylene-propylene-diene rubber blends. J. VINYL. ADDIT. TECHNOL., 11:95,110, 2005. © 2005 Society of Plastics Engineers [source]

    Kinetics of the phase selective localization of silica in rubber blends

    POLYMER COMPOSITES, Issue 10 2010
    Hai Hong Le
    The Fourier transformed infrared (FTIR) spectroscopy on the rubber-filler gel has been used as a tool for the quantitative characterization of the phase selective silica localization in styrene butadiene rubber (SBR)/natural rubber (NR) blends. The so-called rubber-layer L was introduced to describe the selective wetting behavior of the rubber phases to the filler. SBR/NR blends filled with silica were the focus of the experimental investigation. NR shows a higher wetting rate than SBR. Silane addition does not affect the wetting of NR but slowdowns the wetting of SBR. With increasing chamber temperature the value of the rubber-layer L of all mixtures increases owing to the different thermal activated rubber-filler bonding processes. Using the wetting concept the kinetics of silica localization in the phases of heterogeneous rubber blends was characterized. Because of the higher wetting rate of the NR component, in the first stage of mixing of NR/SBR blends more silica is found in the NR phase than in the SBR phase. In the next stage, silica is transferred from the NR phase to the SBR phase until the loosely bonded components of NR rubber-layer are fully replaced by SBR molecules. POLYM. COMPOS., 31:1701,1711, 2010. © 2010 Society of Plastics Engineers. [source]

    Use of carboxylated nitrile rubber and natural rubber blends as retreading compound for OTR tires

    POLYMER ENGINEERING & SCIENCE, Issue 12 2008
    Kaushik Pal
    Ore transportation is one of the important unit operations in a mineral industry. In this study, three raw rubber compounds are prepared in three different blend ratios, and four types of raw rubber samples of pure NR with silica reinforced has been collected from the different tire retreading industries. Blend properties largely depend on the blend ratio and on the blending technique. The improvement in the physical properties such as cure characteristics, mechanical characterization, cross-link density, FTIR, thermal characterization, SEM studies, and dynamic mechanical analysis has been studied in those samples. It has been found that retread rubber made with 80 phr XNBR and 20 phr NR has given the better results when compared with the other samples against all the characterization done. It is also seen that rubber made by the researchers are very good in tough, rigid and these are extremely able to withstand for using as a retread rubber for 35T dump trucks tire when compared with the retread rubber made by the tire retreading industries for different mines in India. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers [source]

    Fracture and yielding behaviors of polystyrene/ethylene-propylene rubber blends: Effects of interfacial agents

    POLYMER ENGINEERING & SCIENCE, Issue 12 2001
    T. Haanh
    The aim of this work is to investigate the effects of two triblock copolymers, used as coupling agents, on fracture and yielding behaviors of a blend of 80 volume % of polystyrene (PS) and 20 volume %of ethylene-propylene rubber (EPR), over a large range of loading rates and temperatures. For this purpose, blends containing different concentrations of two triiblock copolymers were studied at various test conditions. The focus was put on the time-temperature dependence of fracture performance of the blends. Addition of triblock copolymer makes the PS/EPR blend more ductile. The time-temperature dependence of the brittle-ductile transition in fracture performance of the blend is controlled by an energy activation process. The interfacial agent lowers the temperature at brittle-ductile transition and reduces the energy barrier controlling the fracture process. This effect, however, is much more pronounced for the lower molecular weight interfacial agent. The correlation between temperature, loading rate and yield stress of the blends seems to be controlled by a molecular relaxation process according to the Ree-Eyring theory. This model, based on the assumption of two relaxation processes (, and ,) acting in parallel, allows prediction of yield stress at various loading rates and temperatures. Addition of the interfacial agents results in a reduction of the activation energy and an increase in the activation volume V* for both the , and , processes. Furthermore, the similarity of the value of the activation energy ,H, in the , yielding process and the energy barrier ,H controlling the brittle-ductile transition in fracture seems to suggest that a similar secondary relaxation mechanism controls the yielding and the fracture behavior of the blend. [source]

    Dynamically cured natural rubber/EVA blends: influence of NR- g -poly(dimethyl (methacryloyloxymethyl)phosphonate) compatibilizer

    POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 5 2010
    Punyanich Intharapat
    Abstract Graft copolymer of natural rubber and poly(dimethyl(methacryloyloxymethyl)phosphonate) (NR- g -PDMMMP) was prepared in latex medium via photopolymerization. It was then used to promote the blend compatibility of dynamically cured 40/60 natural rubber (NR)/ethylene vinylacetate copolymer (EVA) blends using various loading levels at 1, 3, 5, 7, 9, 12, and 15,wt%. It was found that the increasing loading levels of NR- g -PDMMMP in the blends caused the increasing elastic modulus and complex viscosity until reaching the maximum values at a loading level of 9,wt%. The properties thereafter decreased with the increasing loading levels of NR- g -PDMMMP higher than 9,wt%. The smallest vulcanized rubber particles dispersed in the EVA matrix with the lowest tan , value was also observed at a loading level of 9,wt%. Furthermore, the highest tensile strength and elongation at break (i.e., 17.06 MPa and 660%) as well as the lowest tension set value (i.e., 27%) were also observed in the blend using this loading level of the compatibilizer. Addition of NR- g -PDMMMP in the dynamically cured NR/EVA blends also improved the thermal stability of the blend. That is, the decomposition temperature increased with the addition of the graft copolymer. However, the addition of NR- g -PDMMMP in the blends caused the decreasing degree of crystallinity of the EVA phase in the blend. However, the strength properties of the blend are still high because of the compatibilizing effect. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Compatibility and viscoelastic properties of brominated isobutylene- co - p -methylstyrene rubber/tackifier blends

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2008
    K. Dinesh Kumar
    Abstract Brominated isobutylene- co-p -methylstyrene (BIMS) rubber has been blended with hydrocarbon resin tackifier and alkyl phenol formaldehyde resin tackifier, and the compatibility between the blend components has been systematically evaluated. Dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) studies show that BIMS rubber and hydrocarbon resin tackifier blends are compatible at all blend proportions studied. However, BIMS rubber and phenol formaldehyde resin blends exhibit very limited compatibility with each other and phase separation even at very low phenolic tackifier concentration. Morphological studies of the rubber,resin blends by scanning electron microscopy (SEM) corroborate well with the DMA and DSC results. From the DMA frequency sweep and temperature sweep studies, it is shown that the hydrocarbon resin tackifier acts as a diluent and causes a decrease in the storage modulus values (by reducing the entanglement and network density) in the rubbery plateau region. On the other hand, phenol formaldehyde resin behaves in the way similar to that of the reinforcing filler by increasing the storage modulus values (by increasing the entanglement and network density) in the rubbery plateau zone. The relaxation time estimated from the different zones of frequency sweep master curves provides information about the influence of the two tackifiers on the viscoelastic properties of the BIMS rubber in the respective zones. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]