Mechanical properties, polymers tensile strength

These results demonstrate our biomimetic concept the introduction of modular structures held by sacrihcial weak bonds into a polymer chain can successfully combine the three most fundamental mechanical properties (high tensile strength, toughness, and elasticity) into one polymer. 

Mechanical Property. The tensile strengths of tjhese polymer films at room temperature were between 955-1427 Kg/cm. ... 

For a given polymer, the mechanical properties—modulus, tensile strength, yield stress, etc.—can show order-of-magnitude differences in these various morphologies. Also, molecular structure influences properties, both directly and also indirectly, as it influences the development of a particular morphology (36). 

In the case of both the mechanical properties studied (tensile strength and elongation), on comparison of the properties of the component polymers and the blends, the non-irradiated blends showed negative deviation from the linear additivity of the properties. However, on irradiation, this negative deviation was changed into positive deviation. Some of the mechanical... 

Another extremely important example is the use of carbon filler for rubber. Rubber would be of little value in modern industry were it not for the fact that the filler carbon greatly enhances its mechanical properties lie tensile strength, stiffness, tear resistance, and abrasion resistance. Enhancement of these properties is called reinforcement, and the fillers which produce the strengthening effect are known as reinforcing fillers. Other fillers may not appreciably increase strength, but they may improve other properties of the polymer, thus, making it easier to mold, which reduces cost. 

Incorporation of nanomaterials having different size and shapes such as spheres, fibers, whiskers, or plates into polymer matrices enhances the mechanical properties like tensile strength, modulus, stifhiess, and impact strength significantly. Also other physical properties like barrier, optical, thermal resistance, nonflammability, etc., can be improved by the introduction of nanomaterials. Nanomaterials exhibit some unique properties, which are completely different from their corresponding bulk materials. There are mainly three reasons for the improved performance of polymer nanocomposites. The first reason is the increased relative surface area (aspect ratios) and its associated quantum effects exhibited by nanoparticles. As the size of a particle decreases, the proportion of the number of atoms present on the surface will be more as compared to the atoms present in the bulk. The smface atoms exhibit very different properties compared to that of bulk atoms and hence, the properties of nanomaterials are determined by the properties of surface atoms, rather than that of bulk atoms. Thus the nanoparticles that possess a large surface area per unit mass exhibits, totally different quantum mechanical effects. As the size of the material reaches to nanometer size, most of the properties like mechanical, catalytic, electrical, optical properties, etc., can change. 

Mechanical properties, particularly tensile strengths and stiffness, depend upon the degree of orientation achieved. This is limited to some extent by the fabrication method and type of article produced, as shown schematically in Fig. 8.15. Thus, a compression-moulded unoriented LCP has mechanical properties similar to that of a conventional isotropic polymer. On injection moulding, tensile bars of MCLCPs generally show superior mechanical moduli to that of conventional glass-fibre-reinforced isotropic thermoplastic (Fig. 8.16),... 

What comes out of the die An anisotropic- or orthotropic- oriented-type structure. This orientation will affect the mechanical properties. The tensile strength will increase in the axial direction and decrease in the transverse direction. The elongation (ductility) will generally be increased in the axial direction for brittle amorphous polymers. However, for ductile crystalline polymers the elongation in the transverse direction can be greater than in the oriented axial direction because of the reorientation of molecular chains that occurs with application of force. 

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