The biobased plastics industry is booming with an annual growth rate of about 30%. Here, we explain what biobased plastics are and go over the latest advancements and trends in the ingredients used to make them.
Plastics make up a large proportion of the things we use today, from phone cases to water bottles. They’re made out of long chains of organic molecules (called “polymers”) and, depending on which molecules make up the chains, they can have vastly different properties. Most plastics are made out of petrochemicals, but the rapidly decreasing amount of fossil fuels has pushed researchers to look for alternative materials to make plastic from. Biobased plastics are emerging as a potential solution.
What are biobased plastics?
Biobased plastics are plastics sourced from renewable feedstocks like corn, sugar cane, or other organic polymers that degrade in the environment within one year. The advantages of using biobased plastics are numerous: agricultural feedstocks have more stable prices compared to petrochemicals, which leads to more stable prices for biobased plastics. Not only that, biobased plastics degrade quickly which will help mitigate our current problem with waste plastics (out of the 8.3 trillion tons of plastics we have ever produced, 6.3 trillion are now waste).
Nature itself contains lots of polymers, from cellulose fibers found in trees to starches in potatoes, so using these polymers as a feedstock for making plastics is a potentially sustainable alternative. Here, we look at three different kinds of plastics sourced from natural feedstocks, also known as biobased plastics.
Sorona fibers from DuPont:
DuPont has developed a plastic fiber called Sorona® EP, for applications as far-ranging as furniture and mobile phone cases. This fiber contains 20-37% renewable materials sourced from corn sugar and is reinforced with glass. Its unique semi-crystalline molecular structure, which features a pronounced kink, gives Sorona its properties. The molding characteristics of Sorona® EP is comparable to high-performance PBT (such as DuPont’s Crastin, used in electrical components and house appliances), but Sorona® EP has a better elastic recovery. It is also resistant to stains and UV degradation, on top of having a low water absorption.
Even though this fiber does contain renewable materials, it still has to be reinforced by glass so it is not entirely biobased. Future development is needed to increase the renewable material percentage the fiber is made from, and to develop more biological processes for both the intermediate and the end products of Sorona. Another area being developed is integrating the fiber with electronic components to produce “smart” electronics.
Corn-derived polylactic acid (PLA):
Polylactic acid, made entirely from corn, is one of the most widely-used biobased plastics. It is made by one of two methods: a ring opening polymerization of lactide or direct polycondensation of lactic acid. The largest producer of PLA is NatureWorks, although multiple Japanese and European companies also produce PLA. It can be used as filaments for 3D printing, cases for electronic devices, and building materials such as wall coverings and flooring.
Because PLA is made entirely from corn, it is compostable and doesn’t produce toxic fumes when incinerated, but it also has to compete for resources with food producers who also use corn (for human and animal foods). The properties of pure PLA are also inferior to conventional thermoplastic polymers, so it has to be reinforced with other polymers before it can be used.
Thermoplastic starch (TPS) from starchy vegetables:
A newer material, TPS uses starchy vegetables (e.g. potatoes) as a feedstock. Compared to cellulose, which comes in fibers, starch is a branched molecule so it comes in crystalline form. This makes destructuring the starch molecule in the presence of plasticizer, a process known as gelatinization, easier. The process is similar to extrusion cooking, which means new technologies don’t have to be developed to produce TPS.
The biggest producer of TPS is Novamont, which blends TPS with other polymers such as PVA in their product called Mater-Bi. It hasn’t found too much use outside of disposable food packaging, utensils, and trash bags because its extreme sensitivity to moisture necessitates a blend with other polymers for TPS to even be usable. Further development is needed to find optimal combinations of TPS with other biobased polymers to create a TPS blend that can be used for other applications.
Conclusion:
Even though global oil supply is expected to be able to keep up with demands until 2020, the problem of accumulating plastic waste continues to drive the search for biodegradable feedstocks to replace petrochemicals in plastic production. With a wide range of plastic materials in development using various renewable feedstocks present, the main challenges involved in commercializing biobased plastics are:
- Balancing the demand for feedstock between the plastics industry and food production;
- Lowering the cost of production enough so that biobased plastics can compete with conventional plastics;
- Creating blends of different biobased plastics to improve their properties for different applications.
With the growing number of environmentally conscious consumers, sustainability is becoming increasingly necessary for companies worldwide. Wondering how your company can achieve this goal in the most cost-effective way without compromising quality? Our team of expert researchers can help. Contact us today!
