Rubber loading

Mechanical Properties of Thermoplastic Elastomer Composition with Varying Waste-Rubber Loading at Constant Rubber/Plastic Ratio of 70 30 (w/w)... 

FIGURE 26.46 Rate of cut growth for six different rubbers (O) gum rubber, (+) loaded with 20 pphr reinforcing black, and ( ) with 50 pphr reinforcing black. (From Lake, G.J. and Lindley, P.B., Rubber J., 146, 10, 1964.)... 

A similar approach has also been developed by Susteric [108], who compares the behavior during low-amplitude deformation of rubbers, loaded with aggregated carbon black, with the visco-elastic behavior of macromolecules undergoing high-frequency deformation. The specific features of the breaking of carbon black aggregates defined by the deformation amplitude of loaded rubbers are described by the above author by a mathematical model developed for the description of the dynamic, visco-elastic behavior of polymer molecules. This approach revealed... 

Styrene-butadiene rubber loaded with lead oxide was studied to determine its effectiveness as shield for y-radiation. The material did have the required performance but it gradually hardened on exposure to radiation ... 

R. S. Rivlin and D. W. Saunders, British Rubber Prod. Res. Ass. Trans. Faraday Soc., 48, 200 (1952). Free energy of deformation for cured rubbers. Load-deformation data on vulcanization covering a wide range of hardness are reported. The mean segment lengths as determined from swelling can be correlated with the deformation data. 

The extension ratio A of rubber loaded in tension is defined by... 

Also investigating surface textiles electrodes, Pylatiuk et al. (2009) compared five different conductive materials three types of silicone rubbers loaded with carbon or other nanoparticles, silver-coated polyamide yams and a flexible thermoplastic elastomer loaded with silver-coated glass microspheres. The results of the test electrodes were compared with those of a standard Ag/AgCl gel electrode. It was found that the silicone mbbers and the coated polyamide yams gave results comparable to the reference gel electrodes. The nanoparticle-loaded silicone mbber gave very favourable results with the ability to be used dry and a signal to noise ratio better than the gel electrode reference. 

The optimum volume fraction of the rubber phase in PMMA is the one that yields maximiun mechanical properties. Increasing the concentration of rubber phase beyond this limit decreases the mechanical properties of blends irrespective of the properties of PMMA. In most of the rubber-thermoplastic blends, 20 to 30% rubber loading is acceptable. Higher rubber loading may also even lead to a reduction in impact strength. 

Figure 12.28. Results of transient permeation experiments for (a) pure silicone rubber membranes (v = 0) and (b) silicone rubber loaded with activated molecular sieves (v = 0.202). CO2, P2 = 79 cm Hg. (Paul and Kemp, 1972.)...

This method was implemented in the last 10 years mainly for rubbers loaded with silica 97,99,102,115,127,134 elastomer matrices were explored... 

FIG. 14-17. Absolute Young s modulus plotted against amplitude of sinusoidal strain (with logarithmic scale) at O.S Hz, for natural rubber loaded with carbon black at various volumes (per 100 volumes of rubber) as indicated..(Payne. )... 

Similarly, when a mixture of maleated EPR (0.7% MA) and non-reactive EPR was blended at a total of 20% rubber loading in PA6, a maximum in impact improvement could be achieved only with a high content (>70%) of the maleated EPR in the rubber mixture. Thus the degree to which a reactive (maleated) rubber can be diluted with a non-reactive rubber seems to depend on the maleic anhydride content of the reactive rubber. In each of these cases, both the degree of grafting and the consequent rubber particle size seem to reach the optimiun requirement for the toughening efficiency at a particular ratio of the mixtures of reactive and non-reactive rubbers. 

This transition in polymer composites containing rubber-dispersed phases is sometimes referred to as the brittle-ductile transition (for obvious reasons). The influence of montmorillonite on this transition through the alteration of the rubber-phase morphology for this TPO is very significant. The tensile modulus for this TPO with 30% rubber loading as a function of montmorillonite content increased from approximately 0.8 GPa with no montmorillonite content to approximately 1.5 GPa for 7% montmorillonite content. It is difficult to decon-volute the contribution of the montmorillonite from the contribution of the rubber-dispersed phase to these mechanical properties. 

At the 4th Rubber Modified Asphalt Conference held in Akron, OH, USA in 2009, a wide-ranging paper was presented by Baumgartner [54] that addressed topics such as modified asphalt formulations, optimisation of the process temperature, and the ground tyre rubber loadings and particle size optimisation. The paper showed that rubber crumb produced from whole tyres contains around 30% reactive material for asphalt modification and that the asphalt source and chemistry directly influence the rubber loading and the final properties of the product. The processing time and temperature are also very important, as is the particle size of the crumb, which affects the efficiency of modification and the long-term performance. 

A.A Ward, A.A. Yehia, A. M. Bishai, F.F. Hanna, A.A. Mansour, B. Stoll, W. von Soden, S. Herminghaus. Dynamic-mechanical properties of solution sturene butadiene rubber loaded with silica. Kautsch. Gummi Kunstst., 61, 569-575, 2008. 

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