What is natural rubber?Natural rubber usually comes from the Para rubber tree or the Hevea brasiliensis. Although this tree is native to Brazil, it is also cultivated in many Asian countries, including India, Indonesia, Vietnam, Thailand and Malaysia. Other sources of natural rubber include the rubber fig, the Panama rubber tree and even the dandelion. However, the Hevea brasiliensis is most popular for natural rubber for commercial use. Natural rubber is an elastomer. This means that it is elastic and can recover to its original form after stretching. It is used in many industries, including the footwear and automotive industries. Creating natural rubber involves extracting latex, a substance produced by rubber trees. Latex is eco-friendly because it is recyclable, and trees do not have to be cut down to get latex.
What is synthetic rubber?Synthetic rubber is produced artificially via the process of polymerization of monomers into polymers. There are two ways to accomplish this - emulsion polymerization or solution polymerization. Because the polymers are produced artificially, synthetic rubber has various properties and, thus, many applications. In fact, we use things made from synthetic rubber every day, such as rubber bands, wetsuits, personal protective equipment (PPE), shoe soles and balloons.
Natural rubber vs synthetic rubber propertiesThe following is a summary of natural and synthetic rubber properties, which depicts their advantages and disadvantages as well.
Natural rubber advantages
- High elasticity
- High tensile strength
- Wear damage resistant (for example, tearing, chipping)
- Insoluble in solvents such as water, acetone, alcohol, diluted acids and alkalis
Natural rubber disadvantages
- Soluble in carbon disulfide, petrol, ether, turpentine and carbon tetrachloride
- Can be damaged by ozone, strong acids, oils, grease and fats
- Not suitable for power transmission systems
- Low-temperature properties
- Not suitable for outdoor applications when exposure to sunlight is a major factor
- Raw material prices are high
Synthetic rubber advantagesThere is a whole range of synthetic rubber varieties, and their properties vary for each. However, generally, synthetic rubber has the following qualities:
- Great durability and longevity
- Resistant to high and low temperatures
- Resistant to ozone
- Resistant to sunlight
- Excellent weathering effect
- Suitable as an electrical insulator
Synthetic rubber disadvantagesWhile there are numerous benefits of using synthetic rubber, general disadvantages include:
- Poor mechanical properties
- Poor tensile strength
- Poor tear strength.
Which is better for kids’ shoes?
Having said all this, you might be wondering which type of rubber is better for children’s shoes. Both natural and synthetic rubber has their own pros and cons, and both are used to make certain parts of kids’ shoes, such as the outsole.
The truth is, neither type of rubber is better than the other. The application of the type of rubber depends very much on the design of the shoe itself. For example, because natural rubber creates a better grip, it’s much better for baby shoes. Alternately, synthetic rubber is more lightweight and bouncy but less durable, making it a popular choice for lightweight children’s shoes.