Thermoplastics can be melted and reshaped over and over again, while thermosetting plastics can only be heated and shaped once. Items made from thermoplastics can easily deform when they are exposed to heat, while those that are made of thermosetting plastics cannot.
All plastics are categorized into either thermoplastics or thermosetting plastics. Unlike thermoplastics, thermosetting polymers form bonds that are not reversible during the curing process. As thermoset plastics can withstand heat, they are used in the manufacture of the handles and lid knobs of cooking pots and in electrical insulation. The items are hard, stiff and resist chemicals.
On the other hand, thermoplastics are used to manufacture kitchen equipment, such as cups, jugs, containers, bottles and plastic spoons. In addition, they make simple home tools and implements, such as piping, wash basins, combs and toys. Thermoplastics can be further categorized into nylon, acrylic, polypropylene, polystyrene, low-density polythene and high-density polythene. The six categories of plastics have different properties of color, degree of malleability and weight.
Similarly, thermoset plastics can be categorized into different types: epoxy resin, melamine formaldehyde, polyester resin and urea formaldehyde. These categories of thermosetting plastics have varying degrees of stiffness, textures and levels of resistance to chemicals.Learn More
Conduction is heat transfer through solid objects, while convection is heat transfer through liquid or gasses. Conduction and convection are both forms of radiation, which is heat transfer.Full Answer >
Heat measures the movement of molecules in an object, while temperature measures the average energy or heat generated by the molecules in an object. The faster the molecules move, the more heat they produce and the higher their temperatures become.Full Answer >
Enthalpy is calculated by summing up the energy changes taking place in individual steps of a chemical process. To arrive at the enthalpy changes, Hess’s law is employed. It states that the enthalpy change accompanying a chemical change is independent of the route by which the chemical change occurs.Full Answer >
Entropy decreases as a result of applying energy to a system to increase its order. However, entropy only decreases locally; the result of the work that decreases the entropy in one location emits other forms of energy elsewhere, increasing global entropy.Full Answer >