synthetic detergent

7/25/2019 Synthetic Detergent

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1.0 Introduction

Detergents are synthetic cleansing agents made from hydrocarbons obtained from

petroleum fractions (petrochemicals). It is not only used as household cleaning materials in

our daily life but also widely applied in industrial as fuel additives in order to prevent fouling.

The first synthetic detergent was developed by the Germans during World War I and started

to develop rapidly since 1 ! . "oaps are often replaced by detergents as it has higher washing

characteristics in hard water. This is because detergents do not form scum with #g $% ions and

&a$% ions in hard water but soaps do. Detergent ions do react with the ions in the hard water

but the magnesium salts and calcium salts formed are soluble in water. ('bayomi $ 1*)

Detergents are amphilic molecules meaning that their structures consist of a polar

+head, (hydrophilic) and a non-polar +tail, (hydrophobic). ydrophilic molecules can

dissolve readily in water but not in oils and grease. In contrast hydrophobic molecules can

dissolve readily in oils and grease but not in water.

Generally detergents can be classified into three main types depending on the charge

on the detergent ion.

(a) Anionic detergents where the head of the detergent particle contains a negatively-

charged ion. "ulphates sulphonates carbo/ylates (soaps) and phosphates are some of

the e/ample of anionic hydrophiles.

Diagram 10 "tructure of al yl ben2enesulfonate detergent

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(b) Cationic detergents where the head of the detergent particle contains a positively-

charged ion. &ationic hydrophiles are some form of an amine product.

Diagram $0 "tructure of 3uaternary ammonium detergent

(c) Non-ionic detergents where there is no charged ion on the head of the detergent

particle. The hydrophiles can be from hydro/yl group.

Diagram *0 "tructure of alcohol etho/ylate detergent (4sb.wi idot.com $ 15)

The basic component of a synthetic detergent is a 6surface active agent6 (surfactant). '

surfactant is formed when a strongly hydrophobic group is bond together with a strongly

hydrophilic group in the same molecule. When surfactant is mi/ed with clean water the

hydrophilic group of surfactant dissolves in water while the hydrophobic group stic s out

from the surface of water. The hydrophilic group will wea en the forces of attraction between

water molecules and lower the surface tension of water. When the surface tension is lowered

the water molecules will spread out and wet the cloth or plates to be cleaned. ence

surfactants act as a wetting agent. In addition surfactants also act as emulsifying agent by

brea ing large drop of oil or grease into smaller droplets that float in water. (7in Toon Wai

8eng and 9n Tin $ 1 )

"ince detergents are synthetic cleansing agent its structure of the hydrocarbon chain

can be modified to produce detergents with specific properties. 4owadays different types of

detergents have been synthesised for specific uses such as shampoo and dish cleaners. '

number of additives are used to enhance the cleaning ability of detergents. :hosphates or

2eolites are added to control the al alinity and soften the water. ;iological en2ymes such as

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amylase lipase and protease are added to brea down fat and protein molecules in food

stains. 9ther constituents include foam stabilisers bleaches fragrances optical whiteners and

fillers to improve the free-flowing properties of powder detergents. (:rimaryinfo.com $ 15)

2.0 Literature Review

The first synthetic detergents are invented by Germans during the


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with napthalene followed by sulponation which is having a short chain al yl naphthalene

sulphonate type structure. With this ind of composition 4e al can only be counted as

moderately good detergents since it didn6t show high efficiency on its usage. owever they

are still being manufactured in large 3uantities for te/tile au/ilaries due to its good wetting

ability.

In the late 1 $ s and early 1 * s 4e al was modified to be more functional.

"ulphonated long-chain alcohols was used to replace short chain al yl naphthalene

sulphonate. It was sold as the neutrali2ed sodium salts together with sodium sulphate as an

e/tender. In the early 1 * s ="' mar et came out with another new type of detergent which

having long-chain al yl aryl sulphonates. ;en2ene was chemically designed as aromatic

nucleus and al yl portion was made from a erosene fraction. owever this latest products by ="' were only available with the presence of sodium sulphate as e/tender. ;oth of these

Germany and ="' products were sold as cleaning materials but didn6t cause a big impact to

the mar et.

vs

't the end of the World War $ al yl aryl sulphonates had almost completely defeated

alcohol sulphates in the number of sales. There are two main reasons that al yl arylsulphonates stabili2ed its position in the mar et.


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In the period of 1 5 ->5 :T ben2ene (an al yl ben2ene made from propylene

tetramer coupled to ben2ene) was used to displace all other type of detergents and gained its

foothold in the mar et. It is because :T ben2ene was very easy to be manufactured and

versatility. =ntil now some of the detergents are still based on :T ben2ene for modification.

In this century there are a lot chemical development which have produced detergents

with different chemical composition. owever there is no 6perfect6 detergent in this world.

There must be a limit to each type of detergents. This is due to the availability of raw

materials in particular country.


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.0 Reaction !echanis"

.1 Anionic #etergent

Alkyl$en%ene sul&onates

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'nionic detergents are characteri2ed by their negatively charged hydrophilic head groups.

The most common of the synthetic anionic detergents are based on the straight straight chain

al ylben2ene sulfonates. =sing a


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al ylben2enesulfonic acid by addition of 1-$B water at o& in order to stabili2e the

products.

.2 Cationic #etergent

With this surfactants the hydrophilic head is positively charged. &ommonly used cationic

surfactants contain a 3uaternary respective tetracoordinated nitrogen atom. The cationic can

be obtained by the reaction of tertiary amines with classical al ylating reagents such as

methyl chloride dimethyl sulfate. The residues E 1 F E * represent the al yl group such as

methyl. The E ! stands for the al yl or aryl part of the al ylating reagent mostly methyl

ben2yl. (Texter, 2001) The 3uaterni2ation reaction is carried out at temperature between

and 1 o& for e/ample0

Tertiary amine 'l yl amine salt

/ample for amine salt0

Dimethyl al yl amine salt

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. Nonionic detergent

'thers

4on-ionic detergents are characteri2ed by their uncharged hydrophilic head groups. The

most important technology in synthesi2ing non-ionic detergents is the reaction of long

chain alcohols with epo/yethane (ethylene o/ide) to form ethers. The reaction withethylene o/ide is most fre3uently in order to increase hydrophilicity and thus water

solubility of alcohols. (Drugbase.de $ 15)

The etho/ylation reactions are normally carried out in batchwise in a stainless steel reactor

at temperature range from 1$ to 1 o& and at pressure of 5-C bar as below0

'lcohol thylene o/ide ther

'lthough they do not contain an ionic group as their hydrophilic component hydrophilic properties are conferred on them by the presence of a number o/ygen atoms in one part of

the molecule which are capable of forming hydrogen bonds with water molecules.

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(.0 )lock *low #iagra"

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Diagram !0 Detergent powder manufacturing process

"tep 10

'nterior Eation =nit

The solid raw materials such as sodium sulphate "T: are transferred to each silo respectively

by pneumatic transport. Then the solid raw materials are put into each solid scale hopper

respectively to be measured and controlled for their feeding amount.

The li3uid tan farm is used as general storage for li3uid raw materials and fuel oil. The

li3uid raw materials that stored in the farm are transported to each high tan respectively by

pump. 'gain the li3uid raw materials is put into each li3uid scale respectively to measure its

feeding amount. The ingredients fed into the mi/er reactor is shown in table $. This unit is

controlled by :8& programmable logic controller. It is easy operation safe and reliable. ( e-

yuan.com $ 15)

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"tep $0

&rutcher

9ther materials li e en2yme "oda 'sh perfume and etc. (listed in Table *) are scaled

continuously basis on the flu/ of detergent powder and mi/ed with the powder prior to

pac aging. The air blown through the mi/ture in fluidi2er and mi/ them into homogeneous

powder. This unit is controlled by :8&. The controller system monitors the whole production

and auto control the parameters in production. The operation of control system includes

manual and auto operation. The software for monitoring includes collection of site

information information alert production report system self-diagnose and so on.

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"tep 50

:ac aging

The final step in the manufacturing of detergents is pac aging. Detergents including

household cleaners are pac aged in cartons bottles or cans. The selection of pac aging

materials and containers involves the consideration of product compatibility stability cost

ease of use and etc.

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+.0 Application o& synthetic detergent

"ynthetic detergent can be classifying into three categories. There are anionic

(negatively charged head) cationic (positively charged head) non-ionic or neutral (uncharged

head).

'nionic detergents have a negatively charged polar head group. The negative charge

of this head group is balanced by the sodium cation (4a%) which is arising from the

manufacturing procedure. owever the negatively charged head group can also interact with

other cations in the water such as magnesium (#g$%) and calcium (&a$%). ard water

contains high levels of these cations. 'nionic detergents are the most common detergents in

laundry detergents dishwashing li3uids and oven cleaners. They are also effective at fabric

softener residue emulsifying oil and clay soils and are high sudsing. 'nionic detergents are

more effective than non-ionic detergents in the wetting of metal surfaces. When reading the

ingredients list on cleaning products identify anionic detergents by referring their names0

"odium 'mmonium #agnesium "ulfate "ulfonate and Gluconate. "ome e/amples are

linear al yl sulfonates (8'") al yl aryl sulfonates such as dodecylben2ene sulfonate

(DD;") and alcohol ether sulfates such as sodium lauryl ether sulfate ("8 "). (


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&ationic detergents have a positively charged polar head group. &ationic

manufactured from wea al alis and strong acids. They are acidic in nature with a p value

less than C. These detergents carry anti-static properties and are effective in repelling dust.

The positive charge in a cationic detergent repels the charged dust in the atmosphere. These

detergents are generally not the primary cleaning agent but are used in as mild antibacterial

agents and fabric softeners. "ample of cationic detergents products are car shampoos

dishwasher detergents and cosmetics. (Tsoler and "osis $ ).

It is common for more than one detergent to be used in a laundry detergent. This is

because the actions of the detergents can reinforce each other giving rise to a greater cleaning

result from the combination than would be e/pected from a mi/ture of the two wor ing

independently. owever anionic and cationic detergents are mismatched because of their

opposite head-group charges.

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,.0 Co"parison

#i&&erences in general &or"ula $etween synthetic detergents and soups

&omparison between synthetic detergent and soap Detergents are soups li e compound which

are used for cleaning purpose. There are sodium salts of long chain al yl ben2ene sulphonic

acids or sodium salts of long chain al yl hydrogen sulphate. Whereas soups are salts of long

chain carbo/ylic acid (&itycollegiate.com).

The general formulae for soups and detergents are as below0

#i&&erences $etween synthetic detergents and soups Living ience Che"istry/ 200

1. #etergent can $e used in hard water as well as so&t water $ut soups are not

suita$le &or use in hard water . This is because soaps will react with #g$%and thus

soaps do not lather in hard water.

2. #etergent &or"s no scu" during washing o& clothes $ut soups does. "cum are not

form during washing of clothes by using detergents and as a result it is easier to wash

clothes with detergent while scum are formed during washing of clothes by using soupand repeated washing with water is necessary to remove the scum completely.

. #etergents are not saved &or hu"an use while soups are saved &or hu"an

consu"ption. Detergents are prepared from coal tar and petroleum which is not saved for

human use while soups are prepared from vegetable oils and animal fats which is saved

for human use.

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(. ynthetic detergents have a stronger cleansing action than soups. Detergents are

synthetic cleansing agents. This means that the structure of the hydrocarbon chain can be

modified to produce detergents with specific properties

+. ynthetic detergents can $e used in acidic water while soup can t $e used in

acidic water. % ions from acids will react with soap ions to produce carbo/ylic acids

molecular si2e that are insoluble in water but for detergent % ion is acidic water do not

combined with detergents ions.

,. ynthetic detergents are non-$iodegrada$le $ut soups are $iodegrada$le. This is

because soups are made from vegetable oils and animal fats which can be composed by

bacteria while detergents are made from coal tar and petroleum which cannot becomposed by bacteria. 's a result detergents cause water pollution.

u""ary di&&erences $etween soup and detergent

"oup Detergent1) "oups are sodium or potassium salts of long

chain fatty acids. The anionic group in soup is

F&99 -.

1) "ynthetic detergents are sodium salts of long

chain al yl hydrogen sulphates or long chain

ben2ene sulphunic acids. The anionic group in

synthetic detergent is -9"9 -* or F"9 -*.

$) "oups are obtained from vegetable oils andanimals fats.

$) "ynthetic detergents are made from coal tar and petroleum.

*) "oups are biodegradable. *) "ynthetic detergents are not biodegradable.

!) "oups do not lather readily in hard water. !) "ynthetic detergents lather readily in hard

water

5) "oups e/hibit wea cleaning actions. 5) "ynthetic detergents e/hibit strong cleaning

actions

>) "cums are separated during use. >) 4o scum is separated during use.

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3.0 Conclusion

In conclusion synthetic detergents produced from petrochemicals have a polar +head,

(hydrophilic) and a non-polar +tail, (hydrophobic). Detergents can be classified into three

types. 'nionic detergents have negatively-charged polar head. &ommon anionic detergent is

al ylben2ene sulfonates. 'l ylben2enesulfonate is produced by


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http0JJwww.ausetute.com.auJdetergent.html H'ccessed * #ar. $ 15 .

&itycollegiate.com ($ 15).D T EG 4T"-"TE=&T=E 9< D T EG 4T"-

"TE=&T=E 9 H'ccessed * #ar. $ 15 .

e-yuan.com ($ 15). Introduction of "pray Dry :owder Detergent :roduct. Honline

'vailable at0 http0JJwww.he-yuan.comJenJdisplayproduct.htmlMproIDP$C15>$ H'ccessed 1

'pr. $ 15 .

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fduce.com ($ 15). :roducts - Washing powder production line. Honline 'vailable at0

http0JJwww.hfduce.comJeproduct.aspMnumP > H'ccessed 1 'pr. $ 15 .

8iving "cience &hemistry. ($ 15). 1 th ed. Delhi0 Eatna "agar pp.$$$-$$!.

4sb.wi idot.com ($ 15). "ynthetic Detergents and "oaps - 4sb 4otes. Honline 'vailable at0

http0JJnsb.wi idot.comJc- -5-5-5 H'ccessed 1 'pr. $ 15 .

4uffieldfoundation.org ($ 15). #a ing soaps and detergents K 4uffield

synthetic detergent

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