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 - -
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.
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.
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.