Natural rubber blends

The diffusion and transport properties of polymers were found to depend heavily on the additives and type of crosslinking. Usually, fillers are added to rubbers in order to cheapen the product and also to improve their properties. Thomas and others have investigated the transport properties of aromatic solvents such as 

Similar to the Nylon/EPR system, the effect of compatibilization on transport properties can be seen in natural rubber/acrylonitrile-butadiene rubber (NR/ NBR) blends compatibilized with poly(ethylene-co-vinyl acetate) (EVAc) [51]. In this case, the penetrant used was benzene. Subsequently, it was noted that the solvent uptake tendency of compatibilized samples was lower, while a greater time lag and minimum values for permeation and diffusion coefficients were exhibited compared to the uncompatibilized blend. The polar CN- end of NBR 

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The reactive extrusion of polypropylene-natural rubber blends in the presence of a peroxide (1,3-bis(/-butyl per-oxy benzene) and a coagent (trimethylol propane triacrylate) was reported by Yoon et al. [64]. The effect of the concentration of the peroxide and the coagent was evaiuated in terms of thermal, morphological, melt, and mechanical properties. The low shear viscosity of the blends increased with the increase in peroxide content initially, and beyond 0.02 phr the viscosity decreased with peroxide content (Fig. 9). The melt viscosity increased with coagent concentration at a fixed peroxide content. The morphology of the samples indicated a decrease in domain size of the dispersed NR phase with a lower content of the peroxide, while at a higher content the domain size increases. The reduction in domain size... 

Mathai, A.E., Singh, R.P., and Thomas, S. Transport of Aromatic Solvents through Nitrile Rubber/Epoxidized Natural Rubber Blend Membranes, Polym. Eng. Set 43(3), 704—712, March 2003. 

The pigment also lends itself to application in elastomers, such as natural rubber blends. It is migration fast enough to satisfy most specifications. P.R.53 1 is also completely bleed resistant in natural rubber, although some color is transferred into the wet cotton cloth liner, the wrapper (Sec. 1.8.3.6). P.R.53 1 is lightfast enough for most applications. Products containing P.R.53 1 are not always entirely fast to hot water or alcohol. 

Ismail, H. Suzaimah, S. Hairunezam, H.M. Curing characteristics, mechanical properties and oil resistance of styrene butadiene rubber/epoxidized natural rubber blends. J. Elastomers Plast. 2002, 34 (2), 119-130. 

Ethylene-Propylene-Diene Rubber/Natural Rubber Blends... 

Chapter 15 Ethylene-Propylene Diene Rubher/Natural Rubber Blends 459... 

Chapter 15 Ethylene-Propylene Diene Ruhher/Natural Rubber Blends 469... 

Knappe [10] described the use of DMA to check the plasticizer level of polybutadiene/natural rubber blends. DMA can also be used to look at coatings on elastomer parts, an example being a polyurethane coating on an EPDM (ethylene propylene diene monomer) bumper part, where the low temperature storage modulus can be a key to component toughness. 

S. Utara, P. Boochathum, Novel dynamic vulcanization of polyethylene and ozonolysed natural rubber blends Effect of curing system and blending ratio. J. Appl. Polym. Sci. 120, 2606-2614 (2011)... 

A.W.M. Kahar, H. Ismail, N. Othman. Effects of polyethylene-grafted maleic anhydride as a compatibilizer on the morphology and tensile properties of (thermoplastic tapioca starch)/ (high-density polyethylene)/(natural rubber) blends... 

The strain recovery curves for (a) XPCL-1.2k/ENR, (b) XPCL-2.0k/ENR, and (c) XPCL-3.6k/ ENR blends. (Reproduced from Chang, Y.-W., Eom, J.-P, Kim, J.-G., Kim, H.-T, and Kim, D.-K. 2010. Preparation and characterization of shape memory polymer networks based on carboxylated telechelic poly( -caprolactone)/epoxidized natural rubber blends. Journal of Industrial and Engineering Chemistry 16 256-260 with permission from Elsevier.)... 

Mina, M. R, Ania, R, Balta Calleja R and Asano, T. 2004. Microhardness studies of PMMA/natural rubber blends. Journal of Applied Polymer Science 91(1) 205-210. 

Nakason, C., Panklieng, Y., and Kamesamman, A. 2004. Rheological and thermal properties of thermoplastic natural rubbers based on poly (methyl methacrylate)/epoxidized-natural-rubber blends. Journal of Applied Polymer Science 92(6) 3561-3572. 

Nakason, C., Tobprakhon, A., and Kaesaman, A. 2005. Thermoplastic vulcanizates based on poly(methyl methacrylate) /epoxidized natural rubber blends Mechanical, thermal, and morphological properties. Journal of Applied Polymer Science 98 3) 1251-1261. 

As the concentration of a normally compatible resin is increased in a rubber-resin blend, a level is reached where two phases appear. Natural rubber blended with a poly (vinyl cyclohexane) resin and styrene-butadiene rubber blended with a polystyrene resin, systems which were compatible at the 50% resin level, appear to have two phases at the 75% resin level. 

Figure 15.6 Scanning electron micrographs of fragile fractnres of starch/natural rubber blends, (a) 20 per cent glycerol and 5 per cent rabber, (b) 30 per cent glycerol and 20 per cent rabber, (c) 40 per cent glycerol and 5 per cent rabber and (d) 40 per cent glycerol and 20 per cent rubber. AH quantities are in w/w based on dry matter. Reproduced with permission from Reference [112].

PLA can be mixed with natural rubber [71]. PLA and natural rubber are melt mixed and vacuum dried. The dried blend is cooled to room temperature, and then chopped into small granules. The composites are obtained by injection molding [71]. Without any interfacial modification, the transition from brittle to ductile failure was observed in this blend. The composite made of PLA and natural rubber blend showed good impact strength when compared to corresponding neat PLA composites [71]. 

Table 1 Medium damping natural rubber blends ...

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