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Natural Rubber Blends (natural + rubber_blend)
Selected AbstractsProcessing and Properties of Biobased Blends from Soy Meal and Natural RubberMACROMOLECULAR MATERIALS & ENGINEERING, Issue 10-11 2007Qiangxian 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 analysisPOLYMER INTERNATIONAL, Issue 5 2001Chantara 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] Hydrogenated natural rubber blends: Aspect on thermal stability and oxidative behaviorJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2009N. 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 LiClO4JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008C. 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 blendsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008B. 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] Use of carboxylated nitrile rubber and natural rubber blends as retreading compound for OTR tiresPOLYMER ENGINEERING & SCIENCE, Issue 12 2008Kaushik 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] Dynamically cured natural rubber/EVA blends: influence of NR- g -poly(dimethyl (methacryloyloxymethyl)phosphonate) compatibilizerPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 5 2010Punyanich 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] | ||||||||||