Stabilisation of water-in-oil emulsions to improve - eTheses ...
Stabilisation of water-in-oil emulsions to improve - eTheses ...
Stabilisation of water-in-oil emulsions to improve - eTheses ...
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<strong>to</strong> lipstick. These extra components are used <strong>to</strong> keep lips s<strong>of</strong>t, moist, and <strong>to</strong> provide<br />
added protection from the sun and dryness.<br />
2.2 Waxes<br />
Waxes are used <strong>to</strong> give and impart gloss and hardness <strong>to</strong> the product, <strong>to</strong> stabilise<br />
the stick and allow it <strong>to</strong> be moulded <strong>in</strong><strong>to</strong> shape and enable application. The ideal<br />
characteristics are obta<strong>in</strong>ed by us<strong>in</strong>g a mixture <strong>of</strong> waxes <strong>of</strong> different melt<strong>in</strong>g po<strong>in</strong>ts<br />
and adjust<strong>in</strong>g the f<strong>in</strong>al melt<strong>in</strong>g po<strong>in</strong>t by <strong>in</strong>corporat<strong>in</strong>g a sufficient amount <strong>of</strong> high<br />
melt<strong>in</strong>g po<strong>in</strong>t wax e.g. carnauba wax, beeswax and candelilla wax (Harry &<br />
Wilk<strong>in</strong>son 1973; Salvador & Chisvert, 2007).<br />
Waxes are <strong>water</strong>-resistant materials made up <strong>of</strong> various substances <strong>in</strong>clud<strong>in</strong>g<br />
hydrocarbons (alkanes and alkenes, branched or normal), ke<strong>to</strong>nes, alcohols,<br />
aldehydes, sterol esters, alkanoic acids, terpenes, and monoesters with molecular<br />
cha<strong>in</strong> length rang<strong>in</strong>g from C12 <strong>to</strong> C38. More commonly waxes are esters <strong>of</strong> a long<br />
cha<strong>in</strong> alcohol other than glycerol and a long cha<strong>in</strong> acid as illustrated <strong>in</strong> Figure 2.4<br />
with the wax ester <strong>of</strong> Carnauba.<br />
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