Why Does Crystallinity Affect Strength?

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Crystallinity significantly impacts the strength of materials like Kevlar due to the arrangement of particles and the nature of their bonding. In crystalline structures, particles are tightly packed and bonded in a uniform manner, enhancing strength through strong covalent bonds. In contrast, materials like graphite have a layered structure where particles are not fully bonded to their neighbors, resulting in weaker overall strength. The differences in bonding and structure between crystalline and non-crystalline materials explain variations in their mechanical properties. Understanding these concepts is essential for materials science and engineering applications.
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Hi,

I found out that Kevlar is a crystalline structured polymer, and this is one of the factors about why its so strong. Could someone explain to me why crystallinity affects strenght?

Thanks.
 
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well, with crystal structures a single particle will have covalent bonds with surrounding particles say for example diamond

then in comparison with graphite both graphite and diamond are covalently bonded but the structure is rather different
graphite is in layers where the particles are not bonding with all the surrounding particles

http://www.chemguide.co.uk/atoms/structures/giantcov.html
i am not good at explaining
 
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