Compatibilization, high-strain properties

Blends of immiscible polymers exhibit a coarse and unstable phase morphology with poor interfacial adhesion. The ultimate properties of these blends are often poorer than those of either component. The poor mechanical properties can be improved with a small amount of an interfacial agent that lowers interfacial tension in the melt and enhances interfacial adhesion in the solid. High-strain properties, such as strength, tensile elongation, and impact strength, especially benefit from compatibilization (I, 2). 

High-strain properties of polymer blends, such as strength, tensile elongation, and impact strength, benefit from compatibilization. These... 

Microfibrils in the blend compatibilized with Kraton G probably formed by drawing of the rubbery shell of the core-shell particle. Important factors would have been the amount of rubber in the shell, the strength of the rubber, and the strength of adhesion to LLDPE. All these factors may have contributed in some degree to the high fracture stress and strain of the blend with Kraton G. The amount of compatibilizer in the shell differed for the various Kratons the thicker coating was certainly one of the reasons Kraton G gave better properties to the compatibilized blend than the Kraton D compatibiliz-ers. 

Figure 12 shows that strain at break of SEBS is highly modified by the incorporation of nanoparticles. Silicates and silica enhance this property to 1500% at 1 wt% incorporation then decrease it at 3 wt% incorporation, while sepiolite decreases the elongation at break to 1000%. Again, on the whole a better dispersion of a filler lead to a higher strain at break. However, formulations which show the best improvement of tear strength are the one which have the worst properties of strain at break, (sepiolite and materials compatibilized with SEBs-g-MA)... 

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