3. Differentiate between thermosetting and thermoplastic polymer?

Thermosetting and thermoplastic polymers are two types of plastics that differ in their properties and applications. Here are the key differences between them:<br /><br />1. **Heating and Cooling**: <br /> - **Thermosetting Polymers**: Once set, they cannot be remelted or reshaped. They undergo a chemical change during the curing process, forming a rigid and insoluble structure.<br /> - **Thermoplastic Polymers**: Can be melted and reshaped multiple times. They do not undergo a chemical change during melting or cooling.<br /><br />2. **Structure**: <br /> - **Thermosetting Polymers**: Have a three-dimensional network structure, making them more rigid and thermally stable.<br /> - **Thermoplastic Polymers**: Have a linear or branched structure, making them less rigid and more flexible.<br /><br />3. **Applications**: <br /> - **Thermosetting Polymers**: Used in applications where high heat resistance and electrical insulation are required, such as in electrical insulation, adhesives, and composite materials.<br /> - **Thermoplastic Polymers**: Used in applications where flexibility and recyclability are important, such as in packaging, automotive parts, and household products.<br /><br />4. **Recyclability**: <br /> - **Thermosetting Polymers**: Not easily recyclable due to their rigid and insoluble nature.<br /> - **Thermoplastic Polymers**: Can be recycled multiple times through melting and reprocessing.<br /><br />5. **Cost**: <br /> - **Thermosetting Polymers**: Generally more expensive due to the complexity of their production process.<br /> - **Thermoplastic Polymers**: Generally less expensive and more versatile in terms of processing and applications.<br /><br />In summary, thermosetting polymers are more rigid, heat-resistant, and not easily recyclable, while thermoplastic polymers are more flexible, recyclable, and less expensive. The choice between them depends on the specific requirements of the application.