Synthetic Fibers and Plastics Class 8 PDF

Synthetic Fibers and Plastics Class -8 Polymers Definition: Polymers are large molecules made up of repeating units called monomers. These are the building blocks of synthetic and natural fibers. Natural Fibers Definition: Fiber...

Synthetic Fibers and Plastics Class -8 Polymers Definition: Polymers are large molecules made up of repeating units called monomers. These are the building blocks of synthetic and natural fibers. Natural Fibers Definition: Fibers obtained from plants and animals, such as cotton, wool, silk, and jute, are called natural fibers. Synthetic Fibers Definition: Fibers that are artificially made using chemical processes are called synthetic fibers. These are man-made and include materials like nylon, rayon, and polyester. Types of Synthetic Fibers Rayon Definition: Rayon is a semi-synthetic fiber made from regenerated cellulose obtained from wood pulp. It is also known as artificial silk. Uses of Rayon: o Used to make clothing like sarees and suits. o Used for home furnishings like bed sheets and curtains. o Used in making tire cords and carpets. Nylon Definition: Nylon is a synthetic polymer known for its strength, elasticity, and durability. It was the first fully synthetic fiber. Uses of Nylon: o Used to make ropes, fishing nets, and tents. o Used in parachutes and seat belts due to its high tensile strength. o Used in making toothbrush bristles and sportswear. Polyester Definition: Polyester is a synthetic fiber made from petroleum products. It is known for its wrinkle resistance and durability. Uses of Polyester: o Used in making clothes like shirts and suits.  o Used in home furnishings like curtains and blankets. o Used in industrial applications like conveyor belts and seat belts. Acrylic Definition: Acrylic is a synthetic fiber used as a wool substitute. It is lightweight, warm, and resistant to moths. Uses of Acrylic: o Used to make sweaters, shawls, and blankets. o Used in furnishing fabrics and carpets. o Used in making artificial fur. Advantages of Synthetic Fibers Durable and long-lasting. Resistant to water, stains, and chemicals. Cost-effective and easy to maintain. Available in a variety of colors and textures. Disadvantages of Synthetic Fibers Non-biodegradable and harmful to the environment. Less breathable compared to natural fibers. Can melt and catch fire easily. Cause skin allergies in some cases. Plastics Definition: Plastics are synthetic materials made from polymers. They can be molded into different shapes and are widely used in daily life. Types of Plastics Thermoplastics Definition: Plastics that soften on heating and can be remolded are called thermoplastics. Examples: Polythene, PVC. Thermosetting Plastics Definition: Plastics that cannot be softened or remolded once set are called thermosetting plastics.  Examples: Bakelite, Melamine. Properties and Uses of Plastics 1. Thermal Conductivity: Plastics are poor conductors of heat. 2. Electrical Conductivity: Plastics are good insulators and are used in electrical wiring. 3. Reactivity: Plastics are resistant to chemicals and do not corrode easily. 4. Effect of Flame: Thermoplastics melt on heating, while thermosetting plastics do not. 5. Strength: Plastics are strong and lightweight. 6. Waterproof: Plastics are resistant to water and moisture. Problems with Plastics Non-biodegradable and persist in the environment for years. Cause soil and water pollution. Harmful to wildlife if ingested. Plastics Management Disposal Plastics should not be burned as they release harmful gases. Proper recycling and disposal methods must be followed. Plastics and Environment Plastics harm the environment by causing pollution and endangering marine life. Recycling of Plastics Recycling helps reduce plastic waste by reusing it to make new products. Reuse of Plastics Reusing plastic items like bottles and containers can minimize waste. Reduce the Uses of Plastics Avoid single-use plastics. Opt for eco-friendly alternatives like cloth or jute bags.