Actions of Soaps + Detergent

Soap Structure

• Formed from base hydrolysis of fats and oils

• Have a polar hydrophilic head, and a hydrophobic tail

Soap Benefits

• Made from natural fats and is hence biodegradable

• Effective for human hygiene

Soap Negatives

• Able to form soap scum in hard water, which is water with high Ca2+ and Mg2+, and hence form insoluable salts, this is because a soap molecule contains a carboxylic ion, which is able to form an ionic force of attraction

Anionic Detergent Structure

• Anionic, negatively charged

• Still has hydrophobic tail

• Head etc Benzene Sulfonate,

Anionic Detergent Benifets

• Do not precipitate in hard water

• Availability of materials, such as petrochemicals

• Suitable for cleaning of textiles

Anionic Detergent Negatives

• Non biodegradable

• Excessive foaming

• Not suitable for use in personal hygiene, strips away to much oil from body

Cationic Detergennt

• Has a hydrophobic tail

Cationic Benefits

• Don’t precipate in hard water

• Cleans plastics better

• Used as fabric softener, reduce friction and static electricity

Cationic Detergent Negatives

• Can kill living things (biocidal)

Non Ionic Detergent Structure

Have a non ionic hydrophilic head, containing an oxygen atom in the chain and a terminal alkanol group

• Hydrophobic taill

Non Ionic Detergent Benifets

• Do not precipate in hard water

• Low foaming detergent useful in low-sudsing applications

• Such as dishwashers

Polymer Average MM

• Related to number of monomer units

• Longer the chain, higher the weight, hence higher strength dispersion force

Polymer Chain Branching

High Density:

• Forms crystalline polymer (tightly ordered and packed)

• Hard and dense material

Low Density:

• Non crystalline

• Low melting point, hence more flexible and soft

Polymer Chain Stiffening

• If a monomer, has a side chain it leads to polymers with reduced flexibility

• The larger the side chain, the less it is able to move around

Polymer Cross Linking

• When two polymers are joined together in 2d network

• Increases strength

• Cross linking agent, such as sulfur is required

Polymer Solubility in Water

• Polymer consist of long chains of carbon, hence dispersion forces are the most common

Polymer Stabiltiy

Most polymers contain C-C, C-H bonds which are very stable

• Some polymers, such as PVC contain C-Cl bonds, which are weaker than C-H and break down in the presence of UV light

Addition Polymer

A polymer formed by adding together without loss of atoms

Polymer Initiation

• Initiator molecule breaks the double bond, (must have double bond)

• etc Hydrogen Peroxide, when is reacted forms a free radical, which want to react

Polymer Elongation/Propagation

• Once a free radical starts the reaction, a new monomer forms, forming another free radical

• Propogation process

Polymer Termination

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Polyethene

Monomer Name: Ethene

Low Density Polyethene

• Has branched chain

• Amorphous (disordered)

• Weak bonding due to disperson forces

• Soft plastic

High Density Polyethene

• Crystaline (ordered chains)

• Stronger dispersion forces

• Denser, tougher and rigid

Polychlorethene

• Monomer is chloroethene

• Polar C-Cl produces string dipole-dipole forces

• C-Cl bond vulnerable to U.V light however

• Adding plasticiser, will soften it by weakening the IMF

Polyphenylethene

• Monomer Name, phenylethen

• Looks like an ethene, but with a benzene ring swapped out with a hydrogen

• Bulky side group hinders rotation and prevents chain flexibility

• Use for takeaway containers

Polytetrafluoroethane

• Monomer Name: 1,1,2,2 - tetrafluoroethane

• Creates a highly polar, symmetrical polymer

• Has weak disperson forces, so is non stick, non-polar, hard to interact

Condensation Polymerisation

• Formed by condensation reaction, elimination of a small molecule, such as water when monomers join together

Polyamides

• Formed by the reaction between dicarboxylic acid and diamine

• There is an amide linkage

• Water molecule is released each time

Nylon-6,6

• Formed between Hexanedioic Acid and Hexane-1,6-diamine

• An amide link is formed

• Alternate between 4 CH2 and 6 CH2

• Water is produced

• High tensile strength (due to H bonding)

• Lightweight material, stretch

PET - Polyethene Terepthalate

• Formed from Benzene-1,4-dioic acid and ethane-1,2-diol

• High mechanical strength due to polar ester group

• Large benzene ring gives strength and stiffness

• Chemically inert

• Used for packaging

Polyester

• Formed by reaction between carboxylic acid, and alcohol