Engineering Materials and Mechanics Module 2 - Manipal University Jaipur, 2023-2024 PDF

B.TECH. FIRST YEAR ACADEMIC YEAR: 2023-2024 Course Name: Engineering Materials and Mechanics COURSE CODE : CV1001 CREDITS : 04 MODE OF DELIVERY : OFFLINE FACULTY : DR SOURAV KUMAR DAS EMAIL-ID : [email protected]....

B.TECH. FIRST YEAR ACADEMIC YEAR: 2023-2024 Course Name: Engineering Materials and Mechanics COURSE CODE : CV1001 CREDITS : 04 MODE OF DELIVERY : OFFLINE FACULTY : DR SOURAV KUMAR DAS EMAIL-ID : [email protected] MODULE : 1 DATE OF DELIVERY : Jan-May 2024 1 Module-2: Fibers, and polymers, Polymerization and condensation. Engineering properties and uses of PVC, polyethene, Polystyrene - nylon, rayon, and polyesters Relevant Course Outcome To know various types of fibres, and polymers, their engineering properties and applications.  Fibre A fibre is a thin thread of a natural or artificial substance, with high tensile capacity Samples of steel and copper fibres (top row), and basalt, plastic, and coconut fibres (bottom row)  Different types of fibres are made up of different types of molecules Animal fibres Proteins Synthetic fibres (Ex. Nylon, Polyester) Long chains of hydrocarbons Plant fibres (Ex. Cotton, Jute) Carbohydrate from Cellulose 4 Classification of Fibre 5 Application of Fibre in Civil Engineering 6 Application of Fibre in Civil Engineering 7  Application of Fibre in Civil Engineering Steel Fiber Reinforced Concrete Steel fiber is a metal reinforcement Increase resistance to cracking, impact, fatigue, and bending, tenacity, durability, and others. Improves long-term behavior, enhancing strength, toughness, and stress resistance 8  Application of Fibre in Civil Engineering Polypropylene Fiber Reinforced (PFR) Glass Fiber Reinforced Concrete Concrete Polypropylene fiber reinforced concrete is Glass fiber reinforced concrete is a also known as polypropene or PP material consisting of numerous These fibers are usually used in concrete extremely fine fibers of glass. to control cracking due to plastic shrinkage Glass fiber has roughly comparable and drying shrinkage. mechanical properties to other fibers They also reduce the permeability of such as polymers and carbon fiber. concrete and thus reduce the bleeding of It is much cheaper and significantly less water. brittle when used in composites. It has similar properties as polyethylene, It is a much poorer thermal insulator but it is harder and more heat resistant. than the glass wool. Polypropylene fiber displays good heat- insulating properties and is highly resistant to acids, alkalies, and organic solvents. 9  Application of Fibre in Civil Engineering Carbon Fibre Polypropylene fiber reinforced concrete is also known as polypropene or PP It has high stiffness, high tensile strength, low weight, high chemical resistance, high- temperature tolerance and low thermal expansion. When mixed with plastic resin and baked, it forms carbon-fiber-reinforced polymer (often referred to as carbon fiber) which has a very high strength-to-weight ratio and is extremely rigid although somewhat brittle. 10  Asbestos is a naturally occurring mineral that is made up of long, thin, fibrous crystals. Asbestos fibers Asbestos: are used to strengthen and fireproof materials. They are also resistant to heat and corrosion Rayon Synthetic Fibre Nylon Terylene Polyester Acrylic 11  Rayon Rayon is a man-made fiber derived from natural sources, primarily cellulose obtained from wood pulp. Semi-synthetic OR Regenerated fiber Important characteristics of Rayon: It is infused with cotton or wool to prepare bedsheets and carpets, respectively. It is also known as artificial silk and can be dyed in a wide variety of colours. Rayon has properties alike to those of silk. It is a man-made fibre and cheaper than silk. It is obtained from wood pulp 12  Usage of Rayon Clothing: Rayon is mostly used to make clothing. Home goods: Rayon is used to make sheets, blankets, curtains, and carpets. Paper products: Rayon is used to make paper towels and napkins. Misc. Products: Rayon is also used to make ropes, fishing nets, and other marine products. Rayon is also uses to make non-woven fabrics, which are used in a variety of applications, such as automotive insulation and medical dressings. 13  Nylon Nylon is the name of a family of synthetic polymers that are commonly used to make a variety of different types of apparel and consumer goods Fully Synthetic Composed of Polyamides Important characteristics of Rayon: Lightweight Exceptional strength Abrasion resistant Easy to wash Resists shrinkage and wrinkling Low moisture absorbency Can be pre-coloured or dyed in a wide range of colors Resistant to damage from oil and many chemicals Poor resistance to continuous sunlight 14  Usage of Nylon The fabric is used for car components that are close to the engine It is used for making toys and many other plastic utilities The fabric is used for making swimwear as it is known for its waterproof nature The resins of the Nylon fabric are used for perfect food packaging Used for tents, ropes, tires and various other military supplies Used to make ropes for rock climbing and parachutes 15  Polyester Polyester is a synthetic fiber and fabric made from petroleum-based chemicals It's a type of plastic, and its technical name is Polyethylene Terephthalate (PET) Fully Synthetic Composed of Ester Important characteristics of Rayon: Polyester is a synthetic or man-made fibre material. Polyester is made up of many units of an ester. It is suitable for making clothing because it is easy to wash and stays crisp and wrinkle-free. A very known polyester is TERELYNE and ACRYLIC 16 Usage of Polyester 17  Engineering Properties of Fibres Tensile Young’s Ultimate Specific Types of Fiber Strength Modulus (GPa) Elongation (%) Gravity (MPa) Rayon 420-630 7 10-25 1.5 Nylon 770-840 4.2 16-20 1.1 Polyester 735-875 8.4 11-13 1.4 Acrylic 210-420 2.1 25-45 1.1 18  POLYMER A polymer is a substance or material made up of large molecules called macromolecules These molecules are made up of many repeating subunits A polymer is a compound having very high molecular weight It is formed by covalent linkage with hundreds of small simple chemical units called monomer. Process of formation of polymer is called polymerization. The properties of polymer are different from the monomer. Molecule weight of polymer is equal to the molecular weight of monomer multiplied by number of monomers. 19 POLYMER 20 Natural Polymer These occur in nature in plants and animals and are very essential for life. For e.g., proteins, nucleic acids, Starch, cellulose, protein, silk, wool and natural rubber are some natural polymers. Synthetic Polymer Synthetic polymers are man-made polymers which include fibres like Teflon and Dacron, synthetic rubbers, Polyethylene, Polystyrene, polyvinylchloride, nylon, polyester Semisynthetic Polymer These are the cellulose acetate and nitrocellulose 21 A linear polymer is a long In branched Crosslinked polymers continuous chain of polymers, monomers Network polymers are polymers in which carbon–carbon bonds with are joined to make long are complex polymers long polymer chains are the remaining two valence chains with side chains that form a three- crosslinked together to bonds attached primarily (branches) of various dimensional network form a 3D matrix of to hydrogen or another lengths originating at of linkages interconnect polymer relatively small random points from a chains. hydrocarbon moiety single linear chain. 22  Elastomers are a type of rubber-like material that are durable and elastic. They are Elastomer made up of polymers that are connected by weak intermolecular forces. This allows the material to withstand mechanical stress and return to its original shape when the stress is removed. Fibres A fibre is a thin thread of a natural or artificial substance, with high tensile capacity. Thermoplastic is a plastic material that softens when heated, solidifies when cooled, Thermoplastics and can be re-melted or molded after cooling. Thermosetting plastics, also known as thermosets, are man-made materials. They are made up of long chains of molecules that are cross-linked, giving them a rigid Thermosetting structure. Plastic They are stronger than thermoplastic materials and are better suited for high- temperature applications. Also resistant to many chemicals, including organic and inorganic acids. Many thermosets are also water-resistant, dielectric, and radiopaque. 23  Condensation polymers are polymers that are formed through a Condensation condensation reaction. This reaction involves linking two smaller Polymer molecules (called monomers) together and releasing a small molecule in the process Addition Polymer Addition polymers are formed by a reaction in which monomer units simply add to one another. The monomers usually contain carbon–carbon double bonds. Addition polymers include polystyrene, polyethylene, polyacrylates, and methacrylate. 24  Polystyrene ✓ Polystyrene (PS) is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. ✓ It is naturally transparent but can be coloured with colorants. ✓ It is one of the most widely used plastics, with the scale of its production being several million tonnes per year. ✓ It is a poor barrier to oxygen and water vapor and has a relatively low melting point. ✓ General-purpose polystyrene is clear, hard, and brittle ✓ It is an inexpensive resin per unit weight. ✓ It can be solid or foamed. 25  Polyethylene ✓ It is an important thermoplastic raising expensively used in very large quantity. ✓ It can be prepared in two forms Low density polythene (LDPE) High density polythene (HDPE) ✓ It is manufactured by the addition polymerisation of ethylene gas. ✓ Ethylene gas is subject of high pressure of 1500 to 3000 atm at 250 ° centigrade. 26  Poly-Vinyl Chloride (PVC) It is a synthetic resin made from the polymerization of vinyl chloride PVC is the world's third-most widely produced synthetic polymer of plastic 27  Poly-Vinyl Chloride (PVC) Properties of PVC ✓ PVC is the most widely used member of the vinyl family. ✓ PVC offers excellent corrosion and weather resistance. ✓ It has a high strength-to-weight ratio and is a good electrical and thermal insulator. ✓ PVC is also self-extinguishing per UL flammability tests. ✓ PVC may be used to temperatures of 140°F (60°C) and is readily available in sheets, rods, and tubing. ✓ PVC may be cemented, welded, machined, bent and shaped readily. 28 29