MANUFACTURED SUBTANCES IN INDUSTRY

BY : NURFARAHAIN BINTI AHMAD4ST

SMK SG ABONG

Introduction

Many industrial products are manufactured for our comfort.

They are either made from sulphuric acid, ammonia, alloys, synthetic polymers, glass, ceramics or composite materials.

MAIN MENU

ALLOY

SYNTHETIC POLYMERS

GLASS & CERAMICS

COMPOSITE MATERIALS

An alloy is a homogenous mixture of two or more elements (especially metals) mixed in a certain fixed percentage.

Alloys are made to improve the hardness, malleability and resistance to corrosion of pure metals.

General properties of pure metals : * ductile- can be drawn into wires

ALLOYS

* malleable- can be hammered into sheets * high melting and boiling points * high density * high electrical and heat conductivityMost metals in their pure form are soft.Metals like iron and copper tend to undergo corrosion readily to form oxides.

A pure metal consists of layers of atoms arranged in an even, orderly, and close-packed manner at fixed position.

Pure metals are rather soft because when a force is applied, one layer of atoms can slide over another.

Metals are ductile or can be stretched.

Some imperfections in the orderly arrangement of atoms in metals that allow some empty space in between the atoms.

When a metal is knocked , atom slide.

Metals are malleable or can be shaped.

the shape of the metal changes

force

Alloys such as bronze, brass, steel, stainless, duralumin and pewter are commonly used in our daily lives.

The uses of each different type of alloys depend on the properties of the alloy.

For example, cutlery is made of stainless steel because stainless steel is shiny and does not rust.

Table 1 The composition, properties and uses of some alloys

Alloy Composition

Properties Uses

Bronze • 90% copper• 10% tin

• Hard and strong• Does not corrode

easily• Has shiny

surface

• In the building of statues or monuments

• In the making of medals, swords and artistic materials

Brass • 70% copper• 30% zinc

• Hard than copper

In the making of musical instruments and kitchenware

Steel • 99% iron• 1% carbon

• Hard and strong • In the construction of buildings and bridges

• In the building of the body of cars and railway tracks

Alloy Composition Properties Uses

Stainless steel

• 74%iron• 8% carbon• 18% chromium

• Shiny• Strong• Does not

rust

• In the making cutlery

• In the making of surgical instruments

Duralumin • 93% aluminium

• 3% copper• 3%

magnesium• 1%

manganese

• Light• Stong

• In the building of the body of aeroplanes and bullet trains

Pewter • 96% tin• 3% copper• 1% antimony

• Lustre• Shiny • Strong

• In the making of souvenirs

Bronze

Brass

Steel

Stainless steel

Duralumin

Pewter

The presence of atoms of other metals that are of different size disturb the orderly arrangement of atoms in the metal.

This reduces the layer of atoms from sliding. Thus, an alloy is stronger and harder than its

pure metal.

THE ARRANGEMENT OF ATOMS IN ALLOYS

Pure metal A Pure

metal B

Alloy

The formation of alloy

Polymers are large molecules made up of many identical repeating sub-units called monomers which are joined together by covalent bonds.

Monomers are joined into chains by a process of repeated linking known as polymerisation.

Synthetic Polymers

polymerisation

Formation of a polymer

A polymer may consist of thousands of monomers. Some polymers occur naturally.

Starch, cellulose, wool, protein, silk and natural rubber are some example of naturally occuring polymers.

Synthetic polymerare man-made polymers.

The monomers used are usually obtained from petroleum after going through the refining and cracking processes.

The monomers used are usually obtained from petroleum after going through the refining and cracking processes.

Synthetic polymers

Synthetic polymer

Synthetic polymers

Synthetic polymer

Monomer

Uses

Polythene Ethene Plastic bags, shopping bags, plastic containers and insulation for electrical wiring

Polypropene Propene Piping, bottle crates, carpets, car batteries and ropes

Polyvinyl chloride, PVC

Chloroethene Artificial leather, water pipes and records

Monomers in synthetic polymers

Synthetic polymer

Monomer Uses

Perspex Methylmethacrylate Safety glass, reflectors, traffic signs and lens

Terylene Hexane-1,6-diolBenzene-1, 4-dicarboxylic acid

Clothing, sails and ropes

Nylon Hexane-1,6-diamineHexane-1, 6-diodic acid

Ropes, clothing and carpets

Synthetic polymer in daily life

With the increasing use of synthetic polymers, there are some drawbacks :Synthetic polymers are non-biodegradable. Disposal of synthetic polymers will use up a large fraction of available landfill space.The raw materials for these polymers are obtained from petroleum, thus depleting the supply of non-renewable source.Burning of synthetic polymers releases pollutant and toxic gases that are harmful to our health. For example, burning of PVC releases hydrogen chloride gas. Gases such as carbon monoxide, carbon dioxide, sulphur dioxide and oxide of nitrogen can cause the green house effect and acid rain.Improper disposal of synthetic polymers also destroy the beauty of the nature , causes flash flood and endanger the wildlife.

•To reduce the demand for landfill space, consumption of limited petroleum reserves and environmental pollution, we should :Reduce, reuse and recycle the non-biodegradable synthetic polymers.

Use the biodegradable plastics (Bioplastic) such as polylactide acid (PLA) plastic and poly-3-hydroxybutyrate (PHB) plastic.

Educate users to the right disposal methods.

Synthetic polymer

Polythene

Nylon

Polypropene

Terylene

Perspex

Polyvinyl cholride, PVC

Biodegradable plastic bag

Glass

The major component of glass is silica or silicon dioxide, SiO2.

Silicon dioxide is the second most abundant elements in the Earth’s crust. It is commonly found in sand.

The most way common of preparing glass is to heat the sand to the temperature of 1700 degree celcius. The molten liquid obtained is the cooled quickly so that it solidifies to produce glass.

Structure of silicon dioxide

Silicon atom

Oxygen atom

During rapid cooling, the particles in the liquid do not have time to return to its original crystalline arrangement. They occupy randomly arranged lattice sites and result s in an amorphus solid. This amorphus structure makes the glass brittle.

The main characteristics of glass are : a. hard but brittle b. chemically inert c. transparent and impermeable (non-porous) d. withstand compression e. good heat and electrical insulators

1. There are four types of glasses : (a) Soda-lime glass (soft glass) * The most common and least expensive

glass (b) Lead crystal glass (soft glass) (c) Borosilicate glass (hard glass) (d) Fused glass (hardest glass) * The simplest and most expensive glass

Types, composition, properties and uses of glass

Type of glass

Production method

Composition

Properties Uses

Fused glass

Silica is heated until it melts at 1 700 degree celcius and cooled rapidly

• Silicon dioxide

• Very high melting point

• High transparency

• Highest resistance to thermal shock (can be heated to an extremely high temperature and then plunged into icy, cold water without cracking)

• Laboratory glass rods

• Telescope mirrors

• Optical fibres

• Lenses

Type of glass

Production method

Composition

Properties Uses

Soda-lime glass

Mixture of silica, sodium carbonate (soda lime) and calcium carbonate (limestone) is heated to 1 500 degree celcius and cooled rapidly

• Silicon dioxide

• Sodium oxide

• Calcium oxide

• Low melting point

• Easily shaped• High chemical

durability• Does not

withstand heat• High thermal

expansion coefficient (expand a lot when heated and contract a lot when cooled)

• Light bulbs

• Window glass

• Drinking glass

• Mirrors

Type of glass

Production method

Composition

Properties Uses

Borosilicate glass

Boron (III) oxide is added to soda-lime glass

• Silicon dioxide

• Sodium oxide

• Calcium oxide

• Boron (III) oxide

• High melting point

• Resistant to thermal shock

• Resistant to chemical attack

• Low thermal expansion coefficient a little)

• Oven glass

• Boiler gage glassware

• Automobile headlights

Type of glass

Production method

Composition

Properties

Uses

Lead crystal glass

Lead (II) oxide is added to soda-lime glass

• Silicon dioxide

• Sodium oxide

• Lead (II) oxide

• High density• High

refractive index

• Soft and easy to melt

• Prism • High

reflective lenses

• Fine crystal tableware

• Decorative glassware

• Lead crystal glassware

Example of glass

Fused glass

Soda-lime glass

Borosilicate glass

Lead crystal glass

Special glasses

Some special glasses have been made for specific purposes such as photochromic glass, conducting glass and bullet-resistant glass.

Silver chloride in photochromic glass darkens the glass when exposed to sunlight and protects the eyes from ultraviolet radiation.

Indium tin oxide (ITO) in conducting glass is able to conduct electricity. It is mainly used to make transparent conductive coatings for liquid crystal display (LCD), flat panel display and plasma display.

Bullet-resisitant glass is usually constructed using a strong but transparent materials such as polycarbonate thermoplastic sandwiched between layers of regular glass. The plastic provides impact resistance while the glass flattens the bullet, thereby preventing penetration.

Ceramics

Ceramics are made from clay. Kaolin, a hydrated aluminosilicate, Al2O.2SiO2.2H2O is an example of clay.

The major component of ceramic is silicate. Silicate is a chemical compound containing silicon, oxygen, and one or more metals.The common way of preparing ceramic is to heat the mouldedclay at a very high temperature.

Ceramic that has been hardened after heating cannot be melted again due to its extremely high heat resistance.

The main characteristics of ceramic are (a) extremely hard but brittle (b) chemically inert (c) opaque and porous (d) withstand compression (e) good heat and electrical insulators

Properties and uses of ceramics

Properties

Uses Example

Hard and strong Construction materials

Tiles, cement, bricks

Withstand high pressure and heat

Construction materials

Furnaces, nuclear reactors

Resistant to chemicals, do not corrode and long-lasting

Ornamental articles Plates, bowls, vases, porcelain, toilet wall tiles, floor

Good electric and heat insulators

Electrical appliances

Ovens, toasters, fuses, spark plugs

Have semiconducting properties and can store charges

Semiconductors Microchips

Ceramic

Special ceramics

Boron nitride is a lubricious ceramic that has high temperature and excellent electrical resistance. It is used to make microwave tubes and low friction seals.

Silicon nitride ceramic that has relatively good shock resistance is used to make skateboard bearings and ignition source of domestic gas appliances. Silicon nitride ceramic that has relatively good shock resistance is used to make skateboard bearings and ignition source of domestic gas appliances. Perovskites, YBa2Cu3O7 is another new ceramic superconductor that contains yttrium, barium, copper and oxygen. It can conduct electricity with virtually no loss of heat energy at 98K.

Composite materials

A composite materials is a structural material that is form by combining two or more different substances such as metal, alloys, glass, ceramics and polymers.

A composite materials is a structural material that is form by combining two or more different substances such as metal, alloys, glass, ceramics and polymers.

Examples of composite materials

1) Reinforced concrete

Concrete is a composite material which consists of mixture of stones, chips and sand bound together by cement.

Concrete is strong but brittle and weak in tension. Steel has good tensile strength.

When concrete is reinforced with steel bars, steel wires of rods, it produces a very tough materials with more tensile strength called reinforced concrete.

Reinforced concrete

Reinforced concrete is relatively cheap and can be moulded into any shape. It is also stronger and better able to withstand tensile forces than concrete alone.

It is used in high-rise buildings, bridges, oil platforms and highway.

2) Superconductor

A superconductor is capable to conduct electricity without any electrical resistance when it is cooled to an extremely low temperature.Metal such as mercury can be a superconductor in 4.2K but it is very expensive to maintain such extremely low temperature.Using a combination of metals and metal oxide, a ceramic composite is found to be superconducting at temperatures higher than 30K. Perovskites is the latest ceramic superconductor that has zero resistance at 95K.

Superconductors have low power dissipation, high-speed operation and high sensitivity.

Superconductors are used in bullet trains (maglev train), magnetic resonance imaging (MRI), computer chips, generators and transformers.

Superconductor

3) Fibre optic

A fibre optic capable consists of a bundle of glass or plastic threads that are surrounded by a glass cladding.

It has high transmission capacity and chemical stability, but low susceptibility to interference and material costs.

It is used in video cameras and local area networks for computers. Besides that, it is used in instruments for examining internal parts of the body or manufactured structural products and to transmit data, voice and image in a digital format.

Fibre optic

4) Fibre glass

Glass is hard, strong, has high density but it is relatively brittle. Plastic is elastic, flexible, has low density but it is not strong.When glass fibres are reinforced in plastic, a strong composite material called fibre glass is produced.

It has high tensile strength, low density, can be easily coloured, moulded and shaped. It can even be made into thin layers, yet very strong.

It is used in water storage tanks, badminton rackets, small boats and helmets.

Fibre glass

Silver chloride and copper (I) chloride crystal are embedded in glass to produce photochromic glass.

When photochromic glass is exposed to light , the chloride ions are oxidised to produce chlorine atoms by releasing electrons.

Cl-(aq) The electron are transferred to silver ions.

Silver ions are reduced by gaining electrons to produce silver atoms.

Ag+(aq) + e-

5) Photochromic glass

Cl(s) + e-

Ag(s)

Silver atoms cluster together and block the transmittance of light. The glass turns dark.

When the glass is removed from light, chlorine atoms are reduced by copper (I) ions to form chloride ions and copper (II) ions.

Cl(s) + Cu+(aq) Cl-(aq) + Cu2+(aq)

The copper (II) ions are further reduced by silver atoms to form silver ions and copper (I) ions.

Cu2+(aq) + Ag(s) Cu+(aq) + Ag+(aq)

The glass becomes transparent again when silver atoms are converted back to silver ions.

Photochromic glass is used in optical lenses, car windshields, lenses in cameras, optical switches and light intensity meters.

Photochromic glass

The needs for new materials for specific purposesWith the high demand of items with specific properties, scientists have invented many new substances to replace many traditional ones.For example, plastics replace wood, optical fibres replace copper wires and synthetic fibres replace cotton and wool.However, alloys, ceramics, glass, polymers produced still have their disadvantages and do not meet certain requirements in industry, communication, construction and transportation.Therefore, composite materials are created for specific application.

The uses of composite materials

THE END