Polymers: • produced by 1. • long molecular chains • good resistance to 2. • thermal and electrical insulators
Types of polymers: •3. polymers → molecular 4. not rigidly connected and ductile • thermosetting polymers → molecular chains 5. linked, thus strong and brittle • elastomer → elastic synthetic 6. (both thermosetting and thermoplastic)
Plastics: 7. polymers designed to be easily 8.
Ceramics: 9. , non-metallic: strong, hard, high 10. , good insulators
11. : Combination of materials with different 12. . They are made of: • matrix → external 13. • reinforcement → cluster of 14.
11.1 Say if the sentences are true (Vero) or false (Falso).
1. Plastic compounds are only synthetic.
2. Plastic materials have a high molecular mass with long molecular chains.
3. Polymerisation is the chemical reaction through which polymers are produced.
4. Thermoplastic polymers have rigidly connected molecular chains.
5. An elastomer can be stretched and returns to its shape because it is elastic.
6. Ceramics can be only chemically produced.
7. Composite materials are the combination of materials with similar properties.
8. The matrix of composites is usually made of metal, polymers, or ceramics.
11.2 Correct the false sentences from the previous exercise.aperta
Soluzione suggerita:1. False, They can be both synthetic or semi-synthetic; 2. True; 3. True; 4. False, Their molecular chains that are not rigidly connected; 5. True; 6. False, It can be also be natural; 7. False, The properties of the combined materials may be very different; 8. True.
12. Read the text and fill in the blanks with the missing words.
Applications of Composites In modern 1. and material science, a class of materials has revolutionised industries across the world. These materials, known as 2. materials, have captured the imagination of researchers, designers, and engineers with their exceptional 3. and versatile applications. They are used in a wide range of 4. and applications, such as: • aerospace: carbon 5. composites are extensively used to manufacture aircraft 6. such as wings thanks to high strength-to-weight ratios; • automotive: composites reduce vehicle 7. and enhance fuel efficiency; • construction: composites are used in structural elements thanks to their corrosion 8. , high strength, durability, and design flexibility; • renewable 9. : composites are used for wind turbine blades since they provide the necessary strength, stiffness, and fatigue resistance to 10. the dynamic loads experienced by wind.