Answer:
Thermosets are polymeric materials that are cross-linked through chemical bonds, resulting in a three-dimensional network structure. These bonds are formed through a chemical reaction called curing, which occurs when the thermoset material is heated or exposed to a catalyst. Once cured, thermosets cannot be melted or reshaped without decomposition, making them strong and durable materials.
One reason why thermosets are normally amorphous is due to the cross-linking process. Amorphous materials do not have a long-range ordered structure, meaning that their molecules are randomly arranged rather than being arranged in a repeating pattern. During the curing process, the molecules of the thermoset material become cross-linked in a random, three-dimensional network structure. This random arrangement of molecules leads to an amorphous structure, rather than a crystalline structure with a repeating pattern.
Additionally, the curing process often involves the breakdown of the original polymer chains, leading to the formation of smaller, cross-linked molecules. These smaller molecules are less likely to form a crystalline structure, further contributing to the amorphous nature of thermosets.
Overall, the cross-linking process and the breakdown of original polymer chains in thermosets lead to the formation of a random, three-dimensional network structure, resulting in an amorphous material.