In addition to plastic, various materials support modern life and industry. We will learn the differences between natural and synthetic materials and the characteristics of new materials.
Basic Knowledge
Classification of fibers:
・Natural fibers: Plant-derived (cotton and hemp) and animal-derived (silk and wool)
・Synthetic fibers: Nylon, polyester, and acrylic. Synthesized from petroleum.
・Semi-synthetic fibers: Rayon and acetate. Made by chemically treating natural cellulose.
Classification of rubber:
・Natural rubber: Made from the sap (latex) of rubber trees. Highly elastic and airtight.
・Synthetic rubber: Examples include styrene-butadiene rubber (SBR). Excellent heat and oil resistance.
Ceramics are inorganic solid materials and include glass, concrete, pottery, porcelain, and fine ceramics (high-purity inorganic materials).
Synthetic fibers (fibers synthesized from petroleum. Nylon, polyester, and acrylic)
Nylon (the world's first synthetic fiber. Developed by DuPont in 1938)
Synthetic rubber (rubber synthesized from petroleum. Excellent heat and chemical resistance)
Ceramics (a general term for inorganic solid materials. Highly heat-resistant, hard, and electrically insulating)
Fine ceramics (functional ceramics of high purity and precision molding. Used in IC substrates and artificial bones)
Carbon fiber (an extremely thin fiber whose main component is carbon. Light and very strong. Used in aircraft and sporting goods)
Further Study
Carbon-fiber-reinforced plastic (CFRP) is especially important as a modern advanced material. It is a composite material combining carbon fiber with plastic (such as epoxy resin). Because it is lighter and stronger than iron, it is widely used in aircraft, automobiles, and sporting goods.
Shape-memory alloys (Nitinol: a Ni-Ti alloy) return to their original shape above a certain temperature even after deformation. They are used in medical stents, eyeglass frames, and satellite antennas. Superconducting materials are advanced materials whose electrical resistance becomes zero below a certain temperature, such as in the coils of linear motor trains.
- Distinguish natural fibers (cotton and silk) from synthetic fibers (nylon and polyester)
- Nylon = the world's first synthetic fiber (1938)
- Ceramics = inorganic solid materials. Heat-resistant and very hard
- Fine ceramics = IC substrates, artificial bones, and cutting tools
- Carbon fiber → light and strong. Used in aircraft and automobiles
- CFRP = carbon-fiber-and-plastic composite material
- Shape-memory alloy = returns to its original shape when heated
Points to Note
① Natural fibers and synthetic fibers have completely different raw materials. Natural fibers come from plants or animals, while synthetic fibers come from petroleum. ② Ceramics are not organic substances but inorganic solids. Distinguish them from metals and organic polymers. ③ Distinguish fine ceramics (the new generation with a high degree of purification) from traditional ceramics such as pottery, porcelain, and glass.
Practice
- Answer the name of the world's first synthetic fiber and the year it was developed.
- Explain, in terms of its properties, why carbon-fiber-reinforced plastic (CFRP) is used in aircraft.
- Name two natural fibers and state the raw material of each (plant or animal).