With the war on plastic gaining momentum every year across industries, plastics made from alternative materials to the traditional petrochemicals currently used to create most plastic are now a very popular area for research and investment.
Although their durability has allowed conventional plastics to become so versatile and used so extensively worldwide, it is the issues surrounding their disposal that is one of their greatest drawbacks. Plastics made from conventional, petroleum oil products are not biodegradable, meaning they have significant and long-term effects on the environment. Although not all plastics made from natural sources are fully biodegradable, those that are degrade in substantially shorter times, and as such, have a less detrimental effect on the environment.
Additionally, sourcing plastics from petroleum oil is not a sustainable process, with a finite amount of supplies available. Conversely, using soya beans and their derivative products is a sustainable method of producing bioplastics. It has been reported that the manufacturing process to create bioplastics from corn uses 50% less fossil fuel than during the process of creating conventional plastics, which includes the fuel needed to grow and harvest the corn before the process of creating plastic from corn even begins. Soya-based plastics are also produced at temperatures substantially lower than their oil-based counterparts, which provides notable energy savings during production.
What Can be made from Soya Bean Plastic?
Soya beans can create polyurethane products and polyester thermoset products. Soya-based plastic is able to possess the same qualities as petroleum plastic.
Soya bean oil, used to make soy polyols, can be used to make:
- Foam insulation
- Automobile panels.
Some of these products, however, are not biodegradable, despite being made from natural materials. This is because they are made from polymer molecules used to achieve the same durability and strength seen in petroleum plastics, and these particular molecules are not able to biodegrade. It is disposable or single use soya plastics such as tableware, trash bags, and food containers and packaging that are biodegradable.
Other products made from soya bean-derived plastic include:
- Shoe soles
An increasingly popular area of interest is the production of electronic items such as cell phones, tablets, and laptops, from soya-based plastic, to reduce the ever-increasing amount of e-waste we generate. E-waste can include any electronic items from cell phones to fridges and televisions, and in 2009, 2.37 million tons of e-waste was generated in the US alone. Creating these items from biodegradable plastics would significantly reduce the amount of damage done to the environment by the mounting problem of e-waste.
Regarding health benefits of using soya-based plastics over oil-based plastics, it is interesting to note that adhesives made from soya reduce the amount of formaldehyde needed, which has been identified as a probable human carcinogen.
Problems with Plastic from Soya Beans
A lot of the research into soya-based plastics was carried out in the 1930s and 1940s, to reduce the cost of plastic production. However, petroleum-based plastic was cheaper to produce after World War 2, and as such became the more popular material. The most famous example of creating a soya-based plastic product in the 1940s is Henry Ford’s experiment in producing plastic car parts. The car was made of 14 plastic panels, all made from soya-based plastic. It was claimed that it was safer than traditional steel cars, and could not be crushed if it rolled over.
However, soya-based plastic is known for its high levels of water sensitivity, which has proved problematic. But this ability to absorb large amounts of water is beneficial when soya-based plastic is used in products such as diapers or sanitary towels.
In the early years of production, the cost of bioplastics was more than that of oil-based plastics, which gave businesses little financial motivation to switch to using bioplastics. However, as oil prices increase, more companies are opting for bioplastics as their prices become lower, and as more consumers demand the companies they support operate under environmentally friendly practices.
More research is required to create more products from soya beans that are also biodegradable. While there are many environmental benefits and an important reduction in the need for carcinogenic pollutants, there still remain some practical drawbacks to soya-based plastics. These include its sensitivity to both water and temperature, which limit its application.