POLYVINYL ALCOHOL (POLYETHENOL)

By Manjot, Dilpreet and Benjamin

IUPAC name: poly(l-hydroxyethylene)

(C2 H4 O)n

General information

Polyethenol also known as Polyvinyl Alcohol is generally known as PVA. It is most commonly used in adhesive products and for making other polymers.

Monomer

PolymerPolyethenol Polymer

O

O O O O

Production

Unlike many vinyl polymers, Polyvinyl Alcohol

is not made via polymerization of thecorresponding monomer.

Hydrolysis

Methyl Alcohol+

Vinyl Alcohol --------------->

Polyvinyl Alcohol

Bonding Within Material

The relatively simple molecules of this material bond using covalent bonds and hydrogen interactions. The mixture of these two bonds in this material give it a relatively high melting point of 230 °C and also a relatively high boiling point as a lot of energy is required to overcome the large quantity of bonds within this material.- Intermolecular bond dissociation enthalpy: 2366kJ/mol- Hydrogen bond dissociation enthalpy: 23kJ/mol

--

Other Physical Data

Relative Molecular Mass: 44g/mol Flash Point: 79.44°c Specific Gravity: 1.19-1.31 Density: 1.19-1.31 g/cm³ Solubility: Soluble In Cold Water, Hot

Water The material is pretty inert. It is not

harmful, does not react very much/easily and can be contained with ease.

Some Uses of PVA

Polyvinyl alcohol has excellent film forming, emulsifying, and adhesive properties.

It is resistant to oil, grease and solvent. PVA is fully degradable and is a quick

dissolver Used in water transfer printing process Used in eye drops and hard contact lens

solution as a lubricant PVA fiber, as reinforcement in concrete

Explanations of Applications

Polyvinyl alcohol is used in eye drops because, when eyes become dry due to a reduced production of mucin by the conjunctiva, it reduces the surface tension of the tears and also has similar properties to the mucin.

Explanations of Applications 2 It is also used a water soluble film, the

degradation of PVOH is influenced by its crystalline structure and molecular weight. The Hydrogens present in the Polyvinyl alcohol have a delta plus charge meaning the delta minus charge on the oxygen atom in a molecule of water will attract the delta positive charge and will surround the hydrogen an cause the film to break down.

Explanations of Applications 3 Polyvinyl alcohol is also used in PET

bottles as a carbon layer, because it helps the bottle when thrown away, to degrade which means less rubbish to deal with.

Explanations of Applications 4 When PVA is added to a Borax a bond

between the oxygen of the borax and the hydrogen of the PVA forms (a hydrogen bond) this new formation links the two substances together, forming a slime. The slime is vicious because the hydrogen bonds let the molecules slide over each other but the covalent bonds within the molecules holds the solid together.

THANKS FOR VIEWING

Sources

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moulded-bodieshard-candies-in-innovative-plastic-moulds-1758253.html

http://en.wikipedia.org/wiki/Polyethylene_terephthalate http://www.practicalchemistry.org/experiments/pva-polymer-

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