nota ringkas

48
TOPIK 1 : BANDING BEZA BAHAN ASLI DAN BAHAN BUATAN MANUSIA BAHAN ASLI BAHAN BUATAN MANUSIA CIRI-CIRI berharga tulen dan semula jadi mudah diurai dan degradasikan berasal daripada tumbuh- tumbuhan, haiwan atau tanah Tahan Lasak Ringan Kukuh Reka bentuk untuk fleksibiliti Tidak mengurai dan didegradasikan dengan mudah Ia biasanya dibuat daripada beberapa bahan semula jadi Boleh diwujudkan oleh proses fizikal dan kimia CONTOH Tanah Getah aloi, plastik

Upload: fazliza-mohamed-nor

Post on 27-Oct-2014

483 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Nota Ringkas

TOPIK 1 :

BANDING BEZA BAHAN ASLI DAN BAHAN BUATAN MANUSIA

BAHAN ASLI BAHAN BUATAN

MANUSIA

CIRI-CIRI berharga

tulen dan semula jadi

mudah diurai dan degradasikan

berasal daripada tumbuh-tumbuhan,

haiwan atau tanah

Tahan Lasak

Ringan

Kukuh

Reka bentuk untuk

fleksibiliti

Tidak mengurai dan

didegradasikan dengan

mudah

Ia biasanya dibuat

daripada beberapa bahan

semula jadi

Boleh diwujudkan oleh

proses fizikal dan kimia

CONTOH Tanah

Getah

Petroleum (Bahan Api)

Bahan-bahan bukan organik (batu)

Rencam (tanah liat, porselin)

aloi,

plastik

bahan komposit,

bahan kimia industri,

sabun

Page 2: Nota Ringkas

Kayu (rotan, buluh, kulit kayu)

Logam (tembaga, gangsa, besi, emas,

perak)

Gentian Semula jadi (benang bulu,

sutera, kapas, flaks, hem, jut, kapok)

detergen.

TOPIK 2 : FEUL

Fuel is any material that can be used to generate energy to produce mechanical

work in a controlled manner. The processes used to convert fuel into energy

include chemical reactions, such as combustion, and nuclear reactions, such

as nuclear fission or nuclear fusion. Fuels are also used in the cells of organisms in a

process known as metabolism. Hydrocarbons are by far the most common source of

fuel in current use, but many other substances can be used as well.

Fossil fuel

Fossil fuels are hydrocarbons, primarily coal and petroleum (liquid

petroleum or natural gas), formed from the fossilized remains of dead plants and

animals[3] by exposure to heat and pressure in the Earth's crust over hundreds of

millions of years[4]. In common parlance, the term fossil fuel also includes

hydrocarbon-containing natural resources that are not derived entirely from biological

sources, such as tar sands. These latter sources are properly known as mineral

fuels.

Fossil fuels release millions of greenhouse gases into the air, but they do have some

benefits:

Provide electricity

Fuel for our automobiles

Energy for heating and cooling

Very cheap

Page 3: Nota Ringkas

There are many disadvantages of using fossil fuels:

Produce greenhouse gases

Non-renewable energy source

Contribute to global warming

Deplete the ozone

Aid in acid rain

Crude Oil

A mixture of a wide range of molecules which is pumped or mined from underground

reservoirs. As a mixture it has very little value; too runny for paving, too thick for an

engine. Fortunately each molecule boils at a different temperature, which is the basis

of distillation.Fractional distillation of crude oil is the first step in the production of

many of the materials we have come to rely on in modern life.

Page 4: Nota Ringkas

Petroleum

Petroleum is a mixture of hydrocarbon molecules. The molecules have different

sizes and numbers of carbon atoms. The small molecules have few carbon atoms

and low boiling points, while the large molecules have many carbon atoms and high

boiling points. In this form, petroleum is difficult to ignite and therefore is of little use.

It must be refined to make useful fuels and chemicals.

Petroleum is used for:

Heating homes

Fueling cars

Gum

Crayons

Dishwashing liquid

Records

Fraction of crude oils and its uses

NameNumber of

Carbon Atoms

Boiling Point

(°C)Uses

Refinery Gas 3 or 4 below 30Bottled Gas

(propane or butane).

Petrol 7 to 9 100 to 150Fuel for car

engines.

Naphtha 6 to 11 70 to 200Solvents

and used in petrol.

Kerosene

(paraffin)11 to 18 200 to 300

Fuel for aircraft

and stoves.

Diesel Oil 11 to 18 200 to 300

Fuel for road

vehicles

and trains.

Lubricating Oil 18 to 25 300 to 400Lubricant for engines

and machines.

Page 5: Nota Ringkas

Fuel Oil 20 to 27 350 to 450Fuel for ships

and heating.

Greases and Wax 25 to 30 400 to 500Lubricants

and candles.

Bitumen above 35 above 500Road surface

and roofing.

TOPIK 3

Ore

An ore is a type of rock that contains minerals with important elements

including metals. The ores are extracted through mining; these are then refined to

extract the valuable element(s).

The grade or concentration of an ore mineral, or metal, as well as its form of

occurrence, will directly affect the costs associated with mining the ore. The ores

must be processed to extract the metals of interest from the waste rock and from the

ore minerals. Ore bodies are formed by a variety of geological processes. The

process of ore formation is called ore genesis.

MINERALS

A mineral is composed of the same substance throughout. If you were to cut a

mineral sample, it would look the same throughout. There are about 3000 different

minerals in the world. Minerals are made of chemicals - either a single chemical or a

combination of chemicals.

PROPERTIES OF MINERALS

Characteristics used in the identification & study of minerals. These

are the most common characteristics used when describing minerals.

Color   – this varies depending on the chemicals present

Page 6: Nota Ringkas

and is the least informative in identifying a mineral

variety

Luster  – what the surface looks like in the light

Specific Gravity  – how heavy it feels, heft

Crystal Form  – shape of crystal, shape the mineral

would take if it had room to grow in a cavity, 

not massive – some minerals have a number of

different crystal shapes

Cleavage   – pattern when mineral is broken – in planes

or conchoidal

Fracture

Tenacity  - toughness, how cohesive the mineral is, if it

falls apart

Hardness  – what it can scratch & what scratches it

Transparency  - The ability to transmit light. Depending

on a number of things, 

rocks & minerals can also transmit light. 

Many rocks that are opaque when in a chunk, are

translucent when cut into very thin slices. 

Gems stones are often valued on how clear, or

transparent they are.

Special Properties– magnetism, chatoyancy,

fluorescence, odor, streak, burn test, conductivity

TOPIC 4

Page 7: Nota Ringkas

ALLOY

alloy is as a material that's made up of at least two different chemical elements,

one of which is a metal. An alloy is a combination, either in solution or compound, of

two or more elements, at least one of which is a metal, and where the resultant

material has metallic properties.

Alloys are often used to enhance properties of a metal. Metallic elements are

blended with other metals or non-metallic substances to give them special qualities,

such as corrosion resistance, greater hardness or more strength. Alloys are made by

melting the main metals and then dissolving the other substances in it.

Alloy Components Typical uses

Alnico

Iron (50%+), aluminium (8-

12%), nickel (15-25%), cobalt (5-

40%), plus other metals such as

copper and titanium.

Magnets

in loudspeakers and

pickups in electric guitars.

AmalgamMercury (45-55%), plus silver, tin,

copper, and zinc.Dental fillings.

Babbitt

metal

("white

metal")

Tin (90%), antimony (7-15%), copper

(4-10%).

Friction-reducing coating

in machine bearings.

Brass Copper (65-90%), zinc (10-35%). Door locks and bolts,

brass musical

Page 8: Nota Ringkas

instruments, central

heating pipes.

Bronze

Copper (78-95%), tin (5-22%), plus

manganese, phosphorus, aluminium,

or silicon.

Decorative statues,

musical instruments.

Cast ironIron (96-98%), carbon (2-4%), plus

silicon.

Metal structures such

as bridge sand heavy-duty

cookware.

Cupro-

nickel

(copper

nickel)

Copper (75%), nickel (25%), plus

small amounts of manganese.Coins.

Duralumin

Aluminium (94%), copper (4.5-5%),

magnesium (0.5-1.5%), manganese

(0.5-1.5%).

Automobile and aircraft

body parts, military

equipment.

GunmetalCopper (80-90%), tin (3-10%), zinc

(2-3%), and phosphorus.Guns, decorative items.

Magnox Magnesium, aluminium. Nuclear reactors.

Nichrome Nickel (80%), chromium (20%).

Firework ignition

devices, heating

elements in electrical

appliances.

Nitinol Nickel (50-55%), titanium (45-50%). Shape memory alloy used

Page 9: Nota Ringkas

in medical items, spectacle

frames that spring back to

shape, and temperature

switches.

PewterTin (80-99%) with copper, lead, and

antimony.

Ornaments, used to make

tableware

before glass became more

common.

Solder

Varies. Old-fashioned solders contain

a mixture of tin (50-70%), lead (30-

50%), copper, antimony, and other

metals. Newer solders dispense with

lead for health reasons. A typical

modern solder has 99.25 percent tin

and 0.75 percent copper.

Connecting electrical

components into circuits.

Steel

(general)

Iron (80-98%), carbon (0.2-2%), plus

other metals such as chromium,

manganese, and vanadium.

Metal structures, car and

airplane parts, and many

other uses.

Steel

(stainless)

Iron (50%+), chromium (10-30%),

plus smaller amounts of carbon,

nickel, manganese, molybdenum,

and other metals.

Jewellery, medical tools,

tableware.

StelliteCobalt (67%), chromium (28%),

tungsten (4%), nickel (1%).

Coating for

cutting tools such as saw

teeth, lathes, and

chainsaws.

Page 10: Nota Ringkas

Sterling

silverSilver (92.5%), copper (7.5%).

Cutlery, jewelry, medical

tools, musical instruments.

White gold

(18 carat)

Gold (75%), palladium (17%), silver

(4%), copper (4%)Jewelry.

Wood's

metal

Bismuth (50%), lead (26.7%), tin

(13.3%), cadmium (10%).

Solder, melting element

in fire sprinkler systems.

TOPIC 5

Aromatic hydrocarbons are a class of chemical substances which are characterized

by having molecular structures which are called benzene rings. The chemically

simplest aromatic hydrocarbon is benzene, and the structure of this hydrocarbon lent

its name to the benzene ring. Many aromatic hydrocarbons are toxic, and they are

unfortunately among the most widespread of organic pollutants.

Nuclear Substituted Compounds

When the functional group or any substituent, in aromatic compounds is directly

attached to the benzene ring, it is a called nuclear substituted compound. Such

compounds are named as the derivatives of benzene under the IUPAC system.

However, the common names of many such compounds are retained by IUPAC.

Sidechain Substituted Compounds

Aromatic compounds where the functional group is present in the sidechain of the

ring are called sidechain substituted compounds. Sidechain substituted compounds

are named as the phenyl derivatives of the corresponding aliphatic compounds.

Page 11: Nota Ringkas

Physical Properties of Aromatic Hydrocarbons

The melting and boiling points of aromatic hydrocarbons increase with the molar

mass, and are higher than that of the corresponding aliphatic hydrocarbons.

They are soluble in organic solvents,

Insoluble in water, and

Lower densities than water.

USES

As an industrial solvent for fats and oils, rubber, resins etc.

As a starting material for dyes, drugs, perfumes and explosives and polymers

For dry-cleaning of woollen clothes.

TOPIC 6

The manufacture of ethanol from ethene

Ethanol is manufactured by reacting ethene with steam. The catalyst used is solid

silicon dioxide coated with phosphoric(V) acid. The reaction is reversible.

Page 12: Nota Ringkas

Only 5% of the ethene is converted into ethanol at each pass through the reactor. By

removing the ethanol from the equilibrium mixture and recycling the ethene, it is

possible to achieve an overall 95% conversion.

Uses of ethanol

Drinks

The "alcohol" in alcoholic drinks is simply ethanol.

Industrial methylated spirits (meths)

Ethanol is usually sold as industrial methylated spirits which is ethanol with a small

quantity of methanol added and possibly some colour. Methanol is poisonous, and

so the industrial methylated spirits is unfit to drink. This avoids the high taxes which

are levied on alcoholic drinks (certainly in the UK!).

As a fuel

Ethanol burns to give carbon dioxide and water and can be used as a fuel in its own

right, or in mixtures with petrol (gasoline). "Gasohol" is a petrol / ethanol mixture

containing about 10 - 20% ethanol.

Because ethanol can be produced by fermentation, this is a useful way for countries

without an oil industry to reduce imports of petrol.

As a solvent

Ethanol is widely used as a solvent. It is relatively safe, and can be used to dissolve

many organic compounds which are insoluble in water. It is used, for example, in

many perfumes and cosmetics.

Page 13: Nota Ringkas

Uses of methanol

As a fuel

Methanol again burns to form carbon dioxide and water.

It can be used a a petrol additive to improve combustion, or work is currently being

done on its use as a fuel in its own right.

As an industrial feedstock

Most methanol is used to make other things - for example, methanal (formaldehyde),

ethanoic acid, and methyl esters of various acids. In most cases, these are in turn

converted into further products.

Ether is the general name for a class of chemical compounds which contain an ether

group — an oxygen atom connected to two (substituted) alkyl groups. A typical

example is the solvent and anesthetic diethyl ether (ethoxyethane, CH3-CH2-O-CH2-

CH3).

• An ether has two organic groups (alkyl, aryl, or vinyl) bonded to the same

oxygen atom, R–O–R¢

• Formula R-O-R where R is alkyl or aryl.

• Symmetrical or unsymmetrical

Physical properties

Ether molecules cannot form hydrogen bonds among each other, resulting in

a relatively low boiling point comparable to that of the analogous alkanes.

Ethers are more hydrophobic than esters or amides of comparable structure

Ethers are hydrogen bond acceptors- they are more soluble in H2O than are

hydrocarbons

Page 14: Nota Ringkas

Uses of ether:

The following are the general uses of ether,

Diethyl ether is used in anaesthia.

In Grignard reaction,it is used as a solvent. 

Used as a solvent for resins, oils, fats, and gums.

Used for refrigerator purposes.

TOPIC 7

Preaparation of Aldehydes and Ketones

Oxidising alcohols to make aldehydes and ketones

Page 15: Nota Ringkas

The oxidising agent used in these reactions is normally a solution of sodium

or potassium dichromate(VI) acidified with dilute sulphuric acid.

If oxidation occurs, the orange solution containing the dichromate(VI) ions is

reduced to a green solution containing chromium(III) ions.

The net effect is that an oxygen atom from the oxidising agent removes a

hydrogen from the -OH group of the alcohol and one from the carbon to which

it is attached.

[O] is often used to represent oxygen coming from an oxidising agent.

R and R' are alkyl groups or hydrogen. They could also be groups containing

a benzene ring, but I'm ignoring these to keep things simple.

If at least one of these groups is a hydrogen atom, then you will get an

aldehyde. If they are both alkyl groups then you get a ketone.

If you now think about where they are coming from, you will get an aldehyde if

your starting molecule looks like this:

In other words, if you start from a primary alcohol, you will get an aldehyde.

Uses of aldehydes and Ketone

1. manufacture of resins, dyes, and organic acids.

Page 16: Nota Ringkas

2. Formaldehyde can be used to preserve dead animals. Formaldehyde is well

recognized as formalin solution used to defend biological specimens and to

prepare Bakelite, urea-formaldehyde glues and other polymeric products.

3. Benzaldehyde is an almond extract.  Benzaldehyde is used in perfumery with in

dye industries.

4. Acetone is a common fingernail polish remover and is a solvent. Acetone is very

flammable. Acetone with ethyl methyl ketones are general industrial solvents.

5. 2-Butanone (MEK, methyl ethyl ketone) is used as a solvent and paint stripper. 2-

Butanone is very flammable.

6. (-)-Carvone is used as spearmint flavoring.

7. (+)-Carvone is used as caraway seed flavoring. Vanillin is the vanilla flavoring.

8. Aldehydes and ketones are used as solvents, starting materials and reagents for

the sysnthesis of other products.

9. Aldehyde is used primarily as an initial material in the manufacture of acetic acid,

ethyl acetic, vinyl acetate, polymers and drugs.

10.Various aldehydes and ketones exemplar, butyraldehyde, vanillin,

acetophenone, camphor, etc. are well recognized in support of their odours and

flavours

TOPIC 8

Uses of Carboxylic Acids:

Page 17: Nota Ringkas

They are used in several food produce and pharmaceuticals to include flavors. Some

of these families are manufactured for apply as solvents that are acetone and for

prepare materials similar to adhesives, paints, resins, perfumes, plastics, fabrics, etc

Methanoic acid: use as rubber, textile, dyeing, leather and electroplating

industries.

Ethanoic acid: use as solvent and as vinegar in food industry.

Hexanedioic acid: manufacture of nylon 6:6.

Ester of benzoic acid: use as perfumery.

Sodium benzoate: use as a food preservative.

Higher fatty acids: use as manufacture of soaps and detergents

ESTERS

Esters are derivatives of the carboxylic acids in which the -OH part of the carboxylic

group has been replaced by -OR group where R may be alkyl or aryl group.

A carboxylic acid contains the -COOH group, and in an ester the hydrogen in this

group is replaced by a hydrocarbon group of some kind. This could be an alkyl group

like methyl or ethyl, or one containing a benzene ring like phenyl.

Esters are compounds formed from the reaction between alcohols and acids. The

word 'ester' alone now signifies by common usage that the acid is an organic acid,

but inorganic acids can also form esters

Uses of Esters

Esters are used as softeners in molding and plastic industries, in artificial fragrances

or scents, as solvents in pharmaceutical industries, as industrial solvents for making

fats, cellulose, paints and varnishes, and used in making artificial food flavors that

are added into food such as ice cream and sweets. 

Esters are used in making various products like plastics, polymers, explosives.

They are also used as solvent for oils, fats, cellulose resins etc..,

Page 18: Nota Ringkas

They are also used in making artificial flavours and essences.

Esters are also being successively used as the alternative to diesel.

The salicylic methylester has amazing fragrance, the formula is given below.

AMIDES

Acid amides may be regarded as the derivatives of carboxylic acids in which -OH

part of the carboxylic group is replaced by the -NH2 group.

Acid anhydrides are considered to be derived from carboxylic acids by the removal

of a molecule of water from the two molecules of the acid.

TOPIC 9

Plastics are synthetic chemicals extracted mainly from petroleum and composed

of hydrocarbons (compounds made from chains of hydrogen and carbon atoms).

Page 19: Nota Ringkas

Most plastics are polymers, long molecules made up of many repetitions of a basic

molecule called a monomer; in effect, the monomers are like identical railroad cars

coupled together to form a very long train.

Thermoplastic polymers can be heated and formed, then heated and

formed again and again. The shape of the polymer molecules are generally

linear or slightly branched. This means that the molecules can flow under

pressure when heated above their melting point.

Thermoset polymers undergo a chemical change when they are heated,

creating a three-dimensional network. After they are heated and formed,

these molecules cannot be re-heated and re-formed.

TOPIC 10

Ammonia (NH3) is an important compound of nitrogen and hydrogen, can take the

form of a strong smelling liquid or gas. It is a colourless gas with a choking smell,

Page 20: Nota Ringkas

and a weak alkali which is very soluble in water.Most popularly, consumer and

commercial products use the alkaline substance to clean grime or fertilize crops.

The Haber process

The raw materials for this process are hydrogen and nitrogen. Hydrogen is obtained

by reacting natural gas - methane - with steam, or through the cracking of oil.

Nitrogen is obtained by burning hydrogen in air. Air is 80 per cent nitrogen; nearly all

the rest is oxygen. When hydrogen is burned in air, the oxygen combines with the

hydrogen, leaving nitrogen behind.

Nitrogen and hydrogen will react together under these conditions:

a high temperature - about 450ºC

a high pressure - about 200 atmospheres (200 times normal pressure)

an iron catalyst

The reaction is reversible.

nitrogen + hydrogen   ammonia

N2(g)       + 3H2(g)   2NH3(g)

Nitric acid

Page 21: Nota Ringkas

The most important and useful oxoacid of nitrogen is nitric acid. Its molecular formula

is HNO3 and molar mass 53 g mol-1.

Ostwald's process

The conversion of ammonia into nitric acid in this process is done through the

following steps:

Step1

Oxidation of ammonia to nitric oxide

Ammonia is oxidized by air in the presence of Pt catalyst at 800°C to give nitric

oxide.

Step 2

Oxidation of NO to NO2

The nitric oxide is oxidised by air at temperature below 100°C, to give nitrogen

dioxide (NO2)

Step 3

Formation of nitric acid

Nitrogen dioxide is then converted to nitric acid by absorbing NO2 in water, in the

presence of air.

Page 22: Nota Ringkas

Uses of Nitric acid

The important uses of nitric acid are as follows:

1) Nitric acid plays a significant role in the manufacture of various products such as:

Explosives like trinitrotoluene (T.N.T.) nitro glycerine, gun cotton, ammonal etc.

Fertilizers such as calcium nitrate, ammonium nitrate etc.

Nitrate salts such as calcium nitrate, silver nitrate, ammonium nitrate.

Dyes, perfumes, drugs etc. from coal tar products.

Sulphuric acid by Lead Chamber process.

2) It is used in the purification of silver, gold, platinum etc.

3) Nitric acid is used in etching designs on copper, brass, bronze ware etc

.

4) It is used to prepare "aqua regia" to dissolve the noble elements.

5) It is used as a laboratory reagent.

Sulphuric acid

Sulphuric acid, H2SO4, is one of the most important industrial chemicals. It is an oily

liquid having a boiling point of 335 ºC, which evolves much heat on dilution with

water. Millions of tons of sulphuric acid are made every year by the CONTACT

PROCESS, which converts raw sulphur, oxygen and water to sulphuric acid.

Step 1: Melted sulphur is burned in a furnace, using air, producing sulphur

dioxide, SO2.

Step 2: The SO2 gas is passed through a tower called a precipitator in order to

remove dust and other impurities which might interfere with the catalyst.

Page 23: Nota Ringkas

Step 3: The SO2 is then washed with water, in a scrubbing tower.

Step 4: The SO2 is then dried in a drying tower.

Step 5: After passing through a heating chamber, the SO2, which is still mixed

with air, is passed through a reactor. There, using vanadium pentoxide, V2O5, as

catalyst, the SO2 is converted to sulphur trioxide, SO3.

Step 6: Finally, the SO3 is absorbed in concentrated sulphuric acid, giving the so-

called oleum or pyrosulphuric acid. This is the diluted with water to give about

98% pure H2SO4.

.

Uses of sulphuric acids in our daily life

In the manufacture of fertilizers, ammonium phosphate and calcium super

phosphate.

In the manufacture of rayon and nylon and also in the preparation of dyes and

drugs from coal tar derivatives.

In the manufacture of the explosives such as Tri-nitro toluene , Tri-nitro glycerine

and picric acid.

In the manufacture of nitric acid, hydrochloric acid and phosphoric acid.

In the manufacture of sodium sulphate for glass industry and ferrous sulphate for

ink industry.

In the purification of petrol, kerosene, and lubricants.

Page 24: Nota Ringkas

It is used in metallurgy for extraction of metals. Leaching of metallic compounds

gives sulphates which on electrolysis gives the metal in pure form .It is used for

pickling of metals.

It is used in storage of batteries.

It is used as a laboratory reagent for the preparation of iodine, carbon monoxide

and hydrogen.

TOPIC 11

Composites are made by combining two or more natural or artificial materials to

maximize their useful properties and minimize their weaknesses. One of the oldest

and best-known composites, glass-fiber reinforced plastic (GRP or FRP),

combines glass fibers (which are strong but brittle) with plastic (which is flexible) to

make a composite material that is tough but not brittle. Composites are typically used

in place of metals because they are equally strong but much lighter.

Composites exist in nature. A piece of wood is a composite, with long fibres of

cellulose (a very complex form of starch) held together by a much weaker substance

called lignin. Cellulose is also found in cotton and linen, but it is the binding power of

the lignin that makes a piece of timber much stronger than a bundle of cotton fibres.

Page 25: Nota Ringkas

Types of Composite

Natural Composites

Composites can be easily found in nature. Wood is an example of a composite

because cellulose fibers are held together by substance called lignin. These fibers

can be found in cotton and thread, but it's the bonding power of lignin in wood that

makes it much tougher. Another natural composite is rock and sand, materials used

in concrete. Rock is just smaller rocks held together, and sand is made of small

grains

Mud Bricks

One type of very old composite material invented by early humans was the mud

brick. A normal mud brick is sturdy and resistant to compression, but can break if

bent. Straw is a material that has excellent tensile strength, meaning that it resists

stretching. By combining both, early humans were able to create composite mud

bricks that could resist weight and compression as well as stretching.

Concrete

Concrete is a composite material made of cement, sand, stones and water.

Combined, concrete is stronger than any one of these materials. Concrete is used

heavily in building and road construction.

Fiberglass

Fiberglass is a material made of tiny glass shards held together by resin and other

components. In the automotive industry, fiberglass is important for making body kits.

The body shell for a car is made up of different layers of fiberglass, such as a gel-

coat layer, tissue layer, matting and cloth. The final product is a complete,

Page 26: Nota Ringkas

waterproof, lightweight and strong body kit. Fiberglass can also be a less expensive

alternative to other materials.

Ceramic

Ceramics once referred purely to pottery and to articles made by firing materials

extracted from Earth. Today, the term has a much broader definition. Ceramics

are generally thought of as inorganic and nonmetallic solids with a range of useful

properties, including very high hardness and strength, extremely high melting

points, and good electrical and thermal insulation.

The best-known ceramics are pottery, glass, brick, porcelain, and cement. But

the general definition of a ceramic—a nonmetallic and inorganic solid—is so

broad that it covers a much wider range of materials.

Main properties of glass

These are the main characteristics of glass:

- Solid and hard material

- Disordered and amorphous structure

- Fragile and easily breakable into sharp pieces

- Transparent to visible light

- Inert and biologically inactive material.

- Glass is 100% recyclable and one of the safest packaging materials due to

its composition and properties

Page 27: Nota Ringkas

TOPIC 12

Soaps are sodium or potassium salts of higher fatty acids like stearic, palmitic

and oleic acids. Fatty acids are organic acids that have more than sixteen carbon

atoms in their molecular structure. The sodium soaps are called hard soaps and the

potassium soaps are known as soft soaps. Soaps are obtained from oils and fats.

For e.g., tristearin is got from beef and mutton tallow, tripalmitin from palm oil and

triolein from lard (pig fat), olive oil and cotton seed oil. In India, soap is commonly got

from coconut, groundnut, til and mahua oils.

Manufacture of Soap – Saponification

Page 28: Nota Ringkas

Saponification is the process where oil or fat (tristearin) is treated with sodium

hydroxide solution called lye, to form soap and glycerine.

Saponification

Oil or fat is taken in a huge iron-pan called soap kettle and heated with open steam.

10% sodium hydroxide solution (lye) is added in a thin stream. The steam keeps the

mass boiling and ensures thorough mixing as well. Saponification is complete after

several hours to give a frothy mixture of sodium salts and glycerine.

Salting out of Soap

Saponfication is complete when we see a slight excess of the alkali in the

transparent reaction mixture. Common salt or brine is then added to precipitate soap

and heating is continued. Soap forms in the upper layer as a thick mass. This is

known as salting out of soap.

The unused alkali solution in the lower layer is called spent lye or sweet lye. This

along with glycerol and salts is drawn from below the reaction vessel. Glycerol can

be recovered from this.

Finishing

The soap obtained after salting out is boiled again with sodium hydroxide for

complete saponificaiton. This converts all the unsaponified fat. The spent lye is then

drawn off. The solid soap is then boiled with water to dissolve excess of alkali. It is

then allowed to settle when the impure soap called nigre forms the lower layer. The

pure soap in the upper layer is transferred through a swing pipe to a steam-jacketed

tank called crutcher.

Page 29: Nota Ringkas

It is then shredded into small chips, dried to the requisite amount of moisture content

and mixed with colouring substances and perfumes. Some fillers like rosin, sodium

silicate, borax and sodium carbonate are added to laundry soaps. They have

detergent value and are less expensive than soap.

In the next step, the soap is allowed to run into moulds and permitted to solidify. The

bigger blocks are then cut with steel wires into smaller slabs, which are then cut into

smaller cakes and stamped.

Synthetic Detergents

Synthetic detergents possess the desirable properties of ordinary soaps and

can be used with hard water and in acidic solutions as well. Synthetic detergents are

sodium salts of long chain benzene sulphonic acids or sodium salt of long chain alkyl

hydrogen sulphates. Their calcium or magnesium salts are soluble in water.

The hydrophobic part is the hydrocarbon chain and the water soluble part can be:

An anionic group like sulphate or sulphonate

A cationic group like amine salt or quaternary ammonium compound

A non-ionic group like alcohol or ether

Properties

Some of the synthetic detergents with a branched hydrocarbon chain have very

low biodegradability.

They are resistant to bacterial attack and are not fully degraded in sewage

treatment units. Therefore, they cause water pollution when they are discharged

into a river or any other water body.

Phosphate salts present in synthetic detergents cause rapid growth of algae that

deplete the oxygen content in the water. (A condition known as eutrophication).

Due to this aquatic animals die resulting in the imbalance of the ecosystem as

well.

These detergents lower the surface tension of water and act as cleansing agents

(wetting agents).

Page 30: Nota Ringkas

They can be used for delicate fabrics because they do not hydrolyze to give

hydroxyl ions.

They have equal action in both hard and soft water

Soaps Detergents

Soaps are sodium salts of higher fatty

acids

Detergents are sodium salts of long chain

benzene sulphonic acid or the sodium salts

of a long chain alkyl hydrogen sulphate

 Calcium and magnesium salts of

soaps are in soluble in water.

Therefore cleansing action of soap

reduces in hard water

 Calcium and magnesium salts of

detergents are soluble in water. Therefore

cleansing action of detergents remain

unaffected in hard water

 Soaps are prepared from natural oils

and fats

 Synthetic detergents are prepared from

hydrocarbons of petroleum

 Soaps cannot be used in acidic

medium Detergents can be used in acidic medium

 Soaps are biodegradable Most of the detergents are non-

biodegradable

TOPIC 13

. Gelang getah dibuat dari getah, yang merupakan sejenis polimer yang dipanggil

elastomer. Sebagai elastomer, gelang getah berbeza daripada bahan-bahan pepejal

yang lain kerana ia boleh diregangkan lebih daripada empat kali ganda panjang

asalnya dan apabila dilepaskan dengan mudah ia akan kembali ke panjang

asal. Sifat ini dikenali sebagai kekenyalan

Komposisi Getah

Getah Asli ialah polimer tambahan isoprena, C5H8. Nama IUPAC bagi isoprena ialah

2-metilbut-1,3-diena. Sebagai contoh, getah asli adalah sangat kenyal dan dibuat

dariapda monomer isoprena.

Page 31: Nota Ringkas

Pemvulkanan Getah Asli

Pemvulkanan getah asli merupakan satu proses perangkaian silang yang ditemui

oleh Charles Goodyear pada tahun 1839. Goodyear secara tidak sengaja

mendapati bahawa menambah sulfur kepada getah asli diikuti dengan

pemanasan campuran menjadikan getah lebih kuat dan lebih tahan terhadap

pengoksidaan atau tindak balas yang lain. Dalam getah tervulkan, atom-atom

sulfur membentuk rangkaian silang antara rantai-rantai panjang molekul getah

asli. Apabila diregangkan, rantai getah tervulkan tidak boleh mengelangsor di

antara satu sama lain dan terpaksa balik semula kepada bentuk asalnya oleh

rantai silang atom sulfur. Akibatnya getah tervulkan menjadi lebih keras, lebih

kenyal dan kurang melekit apabila panas.

Sifat-sifat getah

mudah terbakar

kenyal dan boleh diregang

reaktif kepada agen kimia seperti minyak, gris dan petrol

fleksibel kerana ia adalah satu termoplastik yang lembut dan mengeras

bila berlaku pemanasan, boleh cair dan terbentuk semula untuk diguna

pakai semula.

tidak telap air. Ini menjadikannya suatu penghalang yang sangat baik

terhadap patogen seperti virus HIV yang menyebabkan AIDS.

Peka kepada penipisan ozon disebabkan oleh kehadiran ikatan berganda dalam s

Getah asli yang digunakan untuk membuat objek adalah seperti berikut:

• pemadam

Poli-cis-isoprena (getah)

Page 32: Nota Ringkas

• hos air

• gelang getah

• tumit kasut

• sarong tangan, pembedahan dan perubatan

• kondom

• assesori enjin untuk mengurangkan getaran dan hentakan

Getah tervulkan digunakan untuk membuat objek seperti:

alas kereta

tayar kenderaan

hos radiator

pengelap cermin kereta

penyumbat dan pengalas pengantungan (Seals and suspension mountings)

Getah sintetik seperti neoprene digunakan untuk membuat objek seperti:

gaskets

tali pinggang kereta

tali pengangkut

paip atau hos fleksibel untuk industri petrol

bahan-bahan penebat untuk sambungan elektrik di tempat yang ada bahan

kimia

.

Topic 14

Istilah 'polimer' berasal dari perkataan Greek, 'poli' bermaksud 'banyak' dan 'mer'

bermaksud 'bahagian'. Polimer adalah molekul berantai panjang yang dibentuk

daripada penggabungan secara berulangan beberapa unit-unit kecil yang dipanggil

monomer.

Sutera merupakan gentian protein semula jadi yang diperolehi dari kokon yang

dibuat oleh larva ulat sutera yang diternak dalam kurungan. Sutera sebenarnya

diperbuat daripada protein yang dirembeskan dalam keadaan bendalir ulat sutera

Page 33: Nota Ringkas

Sifat-sifat sutera adalah seperti berikut:

• bersinar semula jadi

• mempunyai tekstur licin dan lembut

• tahan asid mineral

• mempunyai kelembapan yang baik

• rintangan rendah terhadap pendedahan cahaya matahari

• keanjalan sederhana dan rintangan kedutan

• paling kuat antara semua gentian semula jadi tetapi kehilangan 20% kekuatan

apabila basah

Kapas adalah serat lembut yang tumbuh di sekitar biji benih pokok kapas, pokok

renek yang berasal dari kawasan tropika dan subtropika di seluruh dunia, termasuk

Afrika, India dan Amerika. Kapas adalah tanaman musim panas, jadi ia mesti

ditanam di kawasan-kawasan yang mempunyai kurang taburan hujan. Gentian yang

paling popular diputar ke dalam benang dan digunakan untuk membuat tekstil yang

lembut, di mana ianya merupakan gentian kain semulajadi yang paling meluas

digunakan dalam pakaian hari ini.

Sifat-sifat kapas adalah seperti berikut:

• kuat

• tahan Lama

• baik unuk mencetak

• selesa

• penyerap kelembapan yang baik

• daya tahan rendah (mudah berkedut)

• rintangan tinggi terhadap pelarut organik dan alkali

Kapas digunakan dalam pembuatan:

• Tuala

• Stokin

• Cadar

• Baju-T

• Penapis kopi

• Seluar Jeans

• Putik kapas dan swab

Page 34: Nota Ringkas

Benang bulu adalah gentian yang berasal dari sel-sel kulit yang khusus, yang

dipanggil folikel. Ia diperolehi dari haiwan dalam keluarga Caprinae, terutamanya

kambing biri-biri, tetapi rambut dari sesetengah spesis mamalia lain seperti kambing,

llamas dan arnab juga boleh dipanggil benang bulu. Benang bulu mempunyai

beberapa kualiti yang membezakan dari rambut atau bulu: ia kerinting, mempunyai

tekstur yang berlainan, anjal dan tumbuh dalam kelompok

Sifat-sifat dari benang bulu adalah seperti berikut :

• bahan-bahan panas

• gentian ketat berkerut

• Sel-sel luar gentian menangkis air sementara sel-sel dalaman menyerap

lembapan

• Keanjalan-wol yang tinggi memiliki keupayaan yang lebih besar untuk kembali

ke panjang asal selepas diregangkan berbanding dengan mana-mana gentian

tiruan.

• Keupayaan penyerap yang tinggi, mampu mengekalkan sehingga 25 peratus

daripada berat dalam kelembapan.

• Pewarnaan benang bulu lebih unggul berbanding dengan gentian tumbuhan

dari segi kekayaan dan kecerahan warna.

Page 35: Nota Ringkas

Topic 15

Kertas adalah bahan yang boleh didapati dalam pelbagai jenis ketebalan dan berat

yang berbeza. Beberapa jenis kertas termasuk:

•kertas bank

• kertas buku

• kertas inkjet

• kertas penunjuk pH

• kertas fotografi

• kertas biasa

• kertas kitar semula

• kertas beras

• kertas tuala

• kertas dinding

• kertas lilin

Page 36: Nota Ringkas

• kertas pasir

• kertas bersalut (permukaan berkilat dan matt)

• kertas biasa

Sifat-sifat kertas

• Berat Asas (GSM)

• Kecerahan, keputihan dan warna

• Kestabilan dimensi

• Kebolehan dilipat (lipatan Double)

• Pembentukan

• Kilat (Gloss)

• Mesin dan Haluan melintang

• Lembapan

• Kelegapan

• ketelapan (porosity)

• pelbagai saiz / Cobb

• kelicinan

• Kekukuhan

• Kenyal (Pemanjangan)

• Rintangan mengoyak

• Suhu dan Kelembapan: keadaan Kertas

• Ketebalan

• Kekuatan permukaan

Langkah-langkah dalam proses membuat kertas:

• Pemprosesan pulpa menggunakan kimia atau mekanikal

• Penambahan bahan tambah

• Pengeringan

• Proses Akhir

Kertas boleh digunakan berdasarkan kepada pelbagai cirinya bergantung kepada

tujuan pengunaannya, seperti:

• Untuk menulis atau mencetak: sehelai kertas boleh menjadi dokumen; ini

mungkin untuk menyimpan rekod (atau dalam keadaan mencetak dari

komputer atau menyalin dari kertas lain: sebagai rekod tambahan) dan untuk

Page 37: Nota Ringkas

komunikasi.

• Untuk mewakili nilai: wang kertas, nota bank, cek, baucar, tiket

• Untuk hiburan: buku, majalah, surat khabar, lukisan, seni

• Untuk pembungkusan: kotak beralur, beg kertas, sampul surat, tisu pembalut,

kertas dinding

• Untuk pembersihan: kertas tandas, sapu tangan, tuala kertas, tisu muka

• Untuk pembinaan: kertas “mache” (paper mache), origami, quiling, kertas

kejuruteraan, pakaian

• Lain-lain kegunaan: kertas pasir, kertas penyerap, kertas litmus, kertas

penunjuk universal, kertas kromatografi, kertas penebat elektrik, kertas turas