Difference Between Shellac and Gel (With Table)

 Shellac is a natural polymer and has a resemblance to a synthetic polymer. It is also considered a natural form of plastic. It is obtained from the female lac bug growing on trees. These are mostly found in India and Thailand. A gel is defined as a solid colloidal substance that has been divided into dispersed phase and the dispersion medium. Here the dispersed phase is liquid, and the medium is solid.

Shellac vs Gel

The difference between shellac and gel is that shellac is a resinous product which is a natural product extracted from the bark of trees on which a female bug grows. It is a natural polymer that has been used for ages to give a fabulous shine to objects. The gel is a type of colloid that appears to be solid, but when disturbed, it shows the liquid part of it.

The raw shellac, which is obtained from trees containing bark shavings and bugs, is heated in long socks like canvas, liquefies the shellac, and percolates from the canvas leaving behind the dead bugs and remains of bark. It is purified or refined into shellac flakes for industrial uses.

The gel is a complex type of solid that also has a natural shine. It looks solid but has liquid-like properties. Its structure shows the molecules of solid having cross-linking, three-dimensional structure with liquid. When left undisturbed, it looks solid in shape. The gel can absorb water and swells up.

Comparison Table Between Shellac and Gel

Parameters of ComparisonShellacGel
DefinitionIt is a natural polymer that is a mixture of resin, wax, and color components.It is a three-dimensional, semi-solid colloidal substance with solid as dispersed phase and liquid as dispersing medium.
FormsPresent naturally in solid formIt is in semi-solid form
PropertyIt gives a natural glossy look and is found in different colors like brown, orange, and red.The gel-like liquid phase is called cytosol, and different ions, proteins, and carbohydrates impart different qualities to the gel.
CharacteristicIt contains wax hence can be used as a waterproofing materialIt contains water as the main component hence gives a humidifying effect
UsesIt is used as a binder, fixers, and for surfacing the wooden objectIt is used as an absorbing and drying agent

What is Shellac?

Shellac is a refined natural form of Lac. Lac is a secretion produced by an insect parasite on trees found in India and Burma and some parts of other Asian countries. The insect sucks phloem juices called sap through its proboscis. The average 20 lb lac is produced by a tree in a year.

Sticklac, as it is called, when extracted from a tree, is processed into seed lac with 3-8% of impurities. It is further purified or refined into shellac flakes for industrial uses. Earlier it was produced manually and was a means of livelihood for many people in and around the forest. It consists of resin which is a polycondensate aldehyde and other hydroxy acids, wax, and other colorful substances.

As the shelf life of dry flakes is more so, it is transported in solid form. But for use, it is dissolved in ethanol to get liquid shellac which is used as a coating on surfaces like wood, etc. it is a form of natural primer that gives glossy shine, insulating qualities, and keeps away the moisture from objects. This biopolymer is thermoplastic in nature, so it exhibits good adhesive properties also. Its coating does not darken for a long time because it is a UV-resistant material. 

What is Gel?

The gel is a form of colliding consisting of solids in the liquid medium. It is semi-solid in appearance. Jellies, jams, curd, butter, and shoe polish are different forms of gel. It is a three-dimensional honeycomb-like structure in which liquid form is entrapped. When left undisturbed, it looks solid, but when a part of it is scooped out, a layer of the entrapped liquid becomes visible on the surface. It is of two types: Elastic gels and nonelastic gels.

Elastic gels are converted into dry form by heating. When they are kept in water, they absorb it and swell up. Examples of elastic gel are agar-agar, gelatin, fruit jams, etc. Non-Elastic gels are also changed in dry mass on heating but cannot be converted into semi-solid form again. 

Examples of nonelastic gel are silica gel, hydroxide of Fe, Al, Cr, etc. Some animal species also secrete gels that protect their bodies from parasites. Our mucus, the vitreous humor of eyes, cartilage, tendons, are also natural gels. Many other substances, when mixed with a thickener or gelling agent, can form a gel, which is used extensively in products like food, paints, and adhesives.

Main Differences Between Shellac and Gel 

  1. Shellac has a resinous structure that consists of resin, wax, and colorful components based on the tree sap on which lac insect grows, whereas Gel is a colloidal form with a three-dimensional structure.
  2. It is a secretion of lac insect on the twigs of trees which help the female insect in laying eggs while the gel is of both natural in origin or may be produced synthetically.
  3. Shellac is processed in solid form but generally used in liquid form by dissolving in its alcohol, whereas Gel is in semi-solid form, but in some cases, the liquid part is removed, and it can be used as a powdery form or in tablets form.
  4. Shellac can be used in nails for a glossy finish. It takes less time to dry and is easy to remove, while gel-based nail paints take more time to apply but last longer.
  5. Shellac does not imbibe water and mostly makes the surface waterproof, whereas Gel can absorb water and swells up.

Conclusion

Shellac and Gel both have a glossy structure with some differences in their characteristics. While a gel is a colloidal structure with a dispersed phase and a dispersion medium, shellac, in simple terms, is a thin nail polish cured under UV lights. The applications of both substances extend to several frontiers.

Jellies, curd, shoe polish, and the like could not have been possible without the invention of gel. On the flip side, shellac is a boon for making dental products and is an important ingredient in the furnishing industry. They are often overlooked, but they live in every home in one form or the other.

References

  1. https://www.sciencedirect.com/science/article/pii/S030881461001513X
  2. https://www.sciencedirect.com/science/article/pii/S1773224717309425
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