The main components of bio natural wax are esters formed by dehydration of long-chain alcohols and long-chain fatty acids. They were first discovered in beehives, and later found in whales and plants. Natural bio waxes are categorized into plant and animal waxes based on their sources.
Whether have double bonds in fatty acids is the basis for classifying saturated and unsaturated waxes. Esters formed by saturated fatty acids and alcohols are called saturated waxes that are the main components in solid natural waxes. If unsaturated fatty acids are involved in esters, they’re called unsaturated waxes. They’re semi-solid or liquid that seldom found in nature. Liquid natural waxes primarily exist in sperm whale oil, jojoba oil and some deep-sea fish oils. Their excellent lubricative properties under high temperature, pressure and speed make them superior lubricants for machinery.
Physical Properties of Natural Bio Waxes
Their melting points are around 40-60°C. Most bio waxes are glossy solids at room temperature, while unsaturated waxes are liquid. They can’t dissolve in water and even more hydrophobic than fats. They are slightly soluble in ethanol and easily soluble in organic solvents like chloroform and benzene. The lower density than water allows them to float. Pure wax is white, but the fat-soluble pigments accumulated through the food chain gives them a yellow appearance.
Chemical Properties of Natural Bio Waxes
Esters make up about 80% of natural bio waxes. The rest are small amounts of fats, long-chain alcohols and fatty acids. Like fat, esters can also be hydrolyzed by digestive enzymes into alcohols and fatty acids to provide energy. They produce water and carbon dioxide when oxidized during respiration or burned completely in the air.
Physiological Functions of Bio Waxes
Animal-secreted waxes are primarily used as waterproof coatings or fat-like energy storage substances. Some aquatic birds and mammals have a shiny layer of wax on their fur. When they dive into water, the wax prevents water from entering the spaces between furs. Water only adheres to the surface of waterproof layer. Then they shake off water from their fur on the land. Without these waterproof bio waxes, their fur would soak up water like cotton. The cold water and evaporation will take away a lot of heat to result in hypothermia and a loss of valuable energy, which is dangerous for wildlife.
Some plants also secrete wax on the surfaces of leaves and fruits to inhibit moisture loss, mechanical abrasion and microbial invasion. The fats of certain deep-sea animals have a lot of unsaturated waxes. They provide energy and maintain body temperature just like fat. Waxes have more carbon-hydrogen bonds and a more compact structure, thus they provide more energy than fat during metabolism.
Bio Natural Wax in Industrial Application
Due to the rapid development of modern industry, synthetic waxes once dominated the market. However, as modern people become more and more concerned about their health, everyone wants to use the safest products. Bio waxes secreted by animals or plants meet market demands as eco-friendly and sustainable products. Unlike synthetic waxes, they are non-toxic, non health harmful and easily degradable product. Growing trees for their production can increase forest coverage and improve environment. Natural bio waxes are mainly used in the pharmaceutical, cosmetic and food industries.
In food industry, the edible waxes are applied as waterproof coatings on fresh vegetables and fruits. They also act as stabilizers and emulsifiers in cosmetics to provide moisturizing, nourishing and anti-aging functions. In particular, some of its antioxidants effectively slow down the fine lines formation and improve skin texture. They are used as excipients and delayed-release agent for drugs in the pharmaceutical industry.
Common Types of Natural Bio Waxes
Beeswax is the earliest bio wax discovered and utilized by humans. It is secreted by glands in the worker bee's abdomen for nest building. Esters are its main component. The other elements are long-chain alkanes, fatty acids, fatty alcohols and trace amounts of minerals. Lipophilic carotenoids from flowers give it a yellow color. Beeswax is a solid with a distinctive fragrance and sweetness at room temperature.
The use of beeswax dates back to thousands of years ago. It coincides with agriculture emergence and bees domestication. Its traces have been found all over the world. For example, beeswax was served as a preservative for mummies by ancient Egyptians. Europeans have made candles and artworks by beeswax since the Middle Ages. Its skin nourishing and anti-aging properties was recognized by ancient Chinese. Nowadays, beeswax from large beekeeping farms is used in food, cosmetics, pharmaceutical and furniture industries.
Spermaceti or whale wax
An adult sperm whale contains about 2000 liters of this white waxy substance in its head. It's a mix of fats and waxes that begins to melt at around 30°C. There's no consensus on its specific function. Some believe that sperm whales use this to adjust their buoyancy because molten spermaceti is less dense. If the whale wants to dive again, it inhales cold seawater to solidify the spermaceti once again. Others suggest that spermaceti in head cavity benefit to the whale's echolocation system, as its low density and high compressibility enhance sound resonance. There's also a theory that spermaceti absorbs the deep-sea pressure to protect their delicate head.
Brazil Wax or Palm Wax
Carnauba wax, also known as Brazil wax or palm wax, is derived from the leaves of the carnauba palm. It has a high melting point and was secreted from leaves surface to prevent moisture loss in the hot tropical sun. The dried palm leaves are beat by wooden sticks to harvest wax. Wax from older leaves is categorized into grades T3 and T4, while T1 food-grade palm wax is harvested from younger leaves. It's often mixed with beeswax to improve its brittle texture.