Non Hydrocarbons

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Non-Hydrocarbon Esters

1. General formula: CnH2n+1COOCmH2m+1

Where n = 0, 1, 2, 3 and m = 1, 2, 3 (n and m = number of carbon)

RCOOR whereR andR represented the same or different alkyl groups.

2. Esters are non-hydrocarbons which contain carbon, hydrogen and oxygen atoms.

3. The functional group in ester is carboxylate group, COO -.

CnH2n+1COOH + CmH2m+1OH> CnH2n+1COOCmH2m+1 + H2O

First part: taken from the alcohol (alkyl group) Second part: taken from the carboxylic acid (-oic to -oate)Name of ester Molecular formula of

ester

Prepared from

Ethyl methanoate HCOOC2H5 Ethanol + Methanoic acid

Methyl ethanoate CH3COOCH3 Methanol + Ethanoic acidPropyl ethanoate CH3COOC3H7 Propanol + Ethanoic acid

Ethyl propanoate C2H5COOC2H5 Ethanol + Propanoic acid

4. Physical properties of ester

Name Odour

3-metylbutyl acetate Banana

Ethyl butanoate Pineapple

Octyl ethanoate Orange

Isoamyl isovalerate Apple

Simple esters are colourless liquid and are found in fruits and flowers. Esters have sweet pleasant smell. Esters are covalent compounds. Esters are insoluble in water but soluble in organic solvent. Esters are less dense than water. Esters are neutral and cannot conduct electricity. The higher and more complex esters have higher boiling points and less volatile.Natural sources:

Vegetable oils (palm oil) and liquids esters can be found in plants derived from glycerol and fattyacids.

Fats are solid esters (milk fat) derived from glycerol and fatty acids. Waxes (beewax) are solid ester derived from long-chain fatty acids and long-chain alcohols.5. Uses of Esters

Preparation of cosmetics and perfumes (esters are volatile and have sweet smell).


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Synthetic esters used as food additives (artificial flavour). Natural esters serves as storage reserve of energy in living things. In plant, wax (esters) helps to prevent dehydration and attack of microorganisms. Esters used as solvents for glue and varnishes.

Esters used to make plastics softer. Esters used to produce polyester (threads and synthetics fabrics) Esters used to produce soap and detergents.

Non-Hydrocarbon Fats

1. Fatrs are non-hydrocarbons which contain carbon, hydrogen and oxygen atoms.

2. Fats (lipids / triglycerides) are belonging to the group in ester.

3. Natural esters are formed from glycerol and fatty acids.

Name of fat Molecular formula of ester Types of

fatty acids

Lauric acid* CH3(CH2)10COOH Saturated

Palmitic acid* CH3(CH2)14COOH Saturated

Stearic acid* CH3(CH2)16COOH Saturated

Oleic oxide ** CH3(CH2)7CH=CH(CH2)7COOH Unsaturated

Linoleic acid*** CH3(CH2)4CH=CHCH2CH=CH(CH2)7COOH Unsaturated

Linolenic

acid***

CH3CH2CH=CHCH2CH=CHCH2CH=CH(CH2)7COOH Unsaturated

* Saturated: C-C single bonds

** Unsaturated (monounsaturated): C=C double bonds

*** Unsaturated (polyunsaturated): C=C double bonds

4. Animal fats have higher percentage of saturated fatty acids than unsaturated fatty acids.

5. Plant oils have higher percentage of unsaturated fatty acids than saturated fatty acids.

6. Physical properties of fats

Saturated Unsaturated

Types of fatty acids C-C single bonds C=C double bondsBonding single double

Melting point higher lower

Sources animals plants

Cholesterol high low

State at room temperature solid liquid


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Fats (animal) in general are solids at room temperature and acted as:

thermal insulator protective cushion to protect the vital organ provide energy and stored in body carry Vitamin A, D, E, K (insoluble in water) Example: butter, fish oil (liquid in room temperature) Fats (plant) are called oils. Oils are liquids at room temperature. Example: olive oil, peanut oil, palm oil and bran oil7. Chemical properties of fats

Unsaturated fats can be converted into saturated fats by hydrogenation (additional reaction) in200C and 4 atm in the presence of nickel catalyst.

Example: production of margarine from sunflower oil of palm oil.8. Effect of fats

Fatty food produce high energy but high consumption of fatty food will results:

obesity raise the level of cholesterol deposition will cause block the flow of blood which lead to stroke and heart attack.9. Palm oil

It is extracted from fresh oil palm fruits. Palm oil extracted from the pulp of the fruits.Steps in extraction of palm oil:

1. sterilising (oil palm fruit)2. stripping3. digestion (crushing the husk and fruit and separate the oil by heating)4. squeezed out the oil5. extraction (separate the oil from water)6. purification the oil (palm oil is treated with phosphoric acid and then steam is passed through to

separate the acid)

7. vacuumPalm kernel oil extracted from the kernel or seed.

Steps in extraction of palm oil:

1. sterilising (oil palm fruit)2. stripping3. crushing the husk and fruit


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4. extracting kernel oil5. purification (purify the oil from kernel)Goodness in palm oil:

higher proportion of unsaturated fats.

easy to digest and absorb. rich in vitamin A (carotenoid) rich in vitamin E (tocophenols and tocotrienols) resist oxidation in high temperature.

Polymers

1. Polymer many small units (monomers) joining together to formed large molecule.

2. Polymer can be classified into two groups:

synthetic polymers / man-made polymers (polythene; PVC polyvinyl chloride; artificial silk;and polypropene)

natural polymers (natural rubber; starch; cellulose; and proteins)3. Natural polymer: Carbohydrates (polysaccharides) (starch, glycogen and cellulose)

General formula: Cx(H2O)ywith the ratio of H:O = 2:1 Carbohydrates have cyclic structure. Monomer: glucose (C6H12H6) Reaction to form polymer: condensation reaction (- H2O)4. Natural polymer: Protein (polypeptide)

Protein consists of carbon, hydrogen, oxygen and nitrogen (some have sulphur, phosphorus andother elements)

Monomer: amino acids Amino acids have two functional group which are carboxyl group (-COOH) and amino group(-

NH2)

Reaction to form polymer: condensation reaction (- H2O)5. Natural polymer: Natural rubber

Extracted from the latex of rubber tree (Hevea brasiliensis) which the tree originates fromBrazil.

A molecule of rubber contains 5000 isoprene units.

Monomer: isoprene, C5H8 or 2-methylbuta-1,3-diene. Reaction to form polymer: additional polymerisation (one of the double bond in isoprene

becomes single bond)

6. Structure of rubber molecule

Latex is colloid (35% rubber particles and 65% water).


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Rubber particle contains rubber molecules which are wrapped by a layer of negatively-chargedprotein membrane. Same charge of rubber molecules repels each other. This prevent rubber

from coagulate.

7. Coagulation process of latex

The process for the coagulation of latex is summarised as:

1. Acid (H+) can neutralise the negatively-charged protein membrane. Example of acid: formicacid, methanoic acid, suphuric acid and hydrochloric acid.

2. The rubber molecules will collide after the protein membrane is broken.3. Rubber molecules (polymers) are set free4. Rubber molecules combine with one another (coagulation).8. Natural coagulation process of latex

For the natural coagulation of latex:

1. Latex is exposed to air without adding acid (duration overnight).2. Coagulation process occurs in slower pace due to the bacteria (microorganism) action which

produce acid)

9. Prevent coagulation process of latex

The following are latex coagulation prevention method:

1. Alkaline / Basic solution is added to the latex. Example: ammonia (NH3).2. Positively-charged hydrogen ion / H+ produced by bacteria can be neutralised by negatively-

charged hydroxide ion / OH

-

from ammonia solution.10. Properties of natural rubber

elastic cannot withstand heat (become sticky and soft above 50C; decompose above 200C; hard

and brittle cooled)

easily oxidised (present of C=C) insoluble in water (due to the long hydrocarbon chains) soluble in organic solvent (propanone, benzene, petrol etc.)11.Vulcanisation of rubber

Vulcanisation process of hardening rubber and increases rubber elasticity by heating it

withsulphur or sulphur compounds.

Methods:

heating natural rubber with sulphur at 140C using zinc oxide as catalyst or dipping natural rubber in a solution of disulphur dichloride (S2Cl2) in methylbenzene.12. Properties of vulcanisation of rubber


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The sulphur atoms are added to double bonds in the natural rubber molecules to formdisulphidelinkages (-C-S-S-C-) / sulphur cross-links between the long polymer chains. Therefore,

vulcanised rubber is more elastics and stronger.

This increases the molecular size and the intermolecular forces of attraction between rubbermolecules. Therefore, vulcanised rubber is more resistant to heat (does not become soft andsticky when hot).

This also reduces the number of carbon-carbon double bonds in rubber molecules. Therefore,vulcanised rubber is more resistant to oxygen, ozone, sunlight and other chemicals.

13. Comparison between the properties of vulcanised rubber and unvulcanised rubber

Properties Vulcanised rubber Unvulcanised rubber

Double bonds Decreases (formation of

sulphur cross-links)

More number of double

bonds

Melting point High (presence of sulphur) Low

Elasticity More elastic (sulphur cross-links prevents the polymer

chain or rubber from slipping

past.

Less elastics

Strength and

hardness

Strong and hard (depends on

degree of vulcanisation)

Weak and soft (polymer

chain of rubber will break

when rubber is over

stretched.

Resistant to

heat

Resistant to heat Poor resistant to heat

Oxidation Resistant to oxidation

(reduction of number of

double bonds per rubber

molecule)

Easily oxidised by oxygen,

UV light (presence of many

double bonds per rubber

molecules)

14. R & D of rubber

RRIM Rubber Research Institute of Malaysia MRB Malaysian Rubber Board Rubber Technology Centre

Various local higher institutions of learning

Non Hydrocarbons

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