Viscoelastic Properties of Natural Rubber Based Blends and IPNs

Mechanical and Viscoelastic Properties of Natural Rubber Based Blends and IPNs... 

The mechanical and viscoelastic behaviours of natural rubber based blends and interpenetrating polymer networks (IPNs) are fimctions of their structures or morphologies. These properties of blended materials are generally not constant and depend on the chemical nature and type of the polymer blends, and also enviromnental faetors involved with any measurements. Preparations of natural rubber blends and IPNs are well known as effeetive modifieation methods used to improve the original meehanieal and viscoelastie properties of one or both of the eomponents, or to obtain new natural rubber blended materials that exhibit widely variable properties. The most common consideration for their mechanical properties include strength, duetility, hardness, impact resistance and fracture toughness, each of which can be deformed by tension, compression, shear, flexure, torsion and impaet methods, or a eombination of two or more methods. Moreover, the viseoelastieity theory is a way to predict the behaviours of deformation of natural rubber blends and IPNs. The time and... 

Natural rubber based-blends and IPNs have been developed to improve the physical and chemical properties of conventional natural rubber for applications in many industrial products. They can provide different materials that express various improved properties by blending with several types of polymer such as thermoplastics, thermosets, synthetic rubbers, and biopolymers, and may also adding some compatibilizers. However, the level of these blends also directly affects their mechanical and viscoelastic properties. The mechanical properties of these polymer blended materials can be determined by several mechanical instruments such as tensile machine and Shore durometer. In addition, the viscoelastic properties can mostly be determined by some thermal analyser such as dynamic mechanical thermal analysis and dynamic mechanical analysis to provide the glass transition temperature values of polymer blends. For most of these natural rubber blends and IPNs, increasing the level of polymer and compatibilizer blends resulted in an increase of the mechanical properties until reached an optimum level, and then their values decreased. On the other hand, the viscoelastic behaviours mainly depended on the intermolecular forces of each material blend that can be used to investigate the miscibility of them. Therefore, the natural rubber blends and IPNs with different components should be specifically investigated in their mechanical and viscoelastic properties to obtain the optimum blended materials for use in several applications. 

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