It is estimated that 99% of all plastics are made from fossil fuels such as oil and gas. The remaining 1% is made from natural raw materials such as corn, sugar cane or potatoes. These bioplastics or biobased plastics are used for e.g. bags, food packaging, and disposable cups.
The term biobased plastics is extremely confusing. This can be plastic that is made from biomass, but that has exactly the same properties as normal plastic. Besides this, some plastics are biodegradable. This can be done through the use of industrial installations or naturally.
Biobased plastics may be considered compostable if these plastics have completely decomposed within 12 weeks in industrial installations. Various types of biodegradable plastics can be distinguished. There are biobased plastics that are biodegradable in the soil such as PHA and TLS. These biobased plastics break down when there is the right combination of micro-organisms, heat, and moisture. There are also biobased plastics that are biodegradable in water. Other biobased plastics can be added to the compost heap.
The conditions in which the plastics are located are important. Low temperatures, little sunlight, and lack of oxygen are not ideal for decaying biobased plastics. On the other hand, you also do not want a bottle made of biobased plastic to fall apart in the store.
A major problem raised by waste processors is that biobased plastics make the recycling of ordinary plastics more difficult. In practice, the consumer supplies a mix of all kinds of plastics, which are not separated. Another disadvantage of biobased plastics is that (artificial) fertilizer, pesticides, and agricultural land are required for production. Making fertilizers and pesticides requires energy and these products pollute the soil and water. Worldwide, there is less and less good agricultural land, which is also needed for e.g. food, wood, cotton, animal feed, and biofuels.
Biobased plastics is a broad and growing category of polymers based on biological materials. These each have their unique properties and applications. The list is constantly being expanded with new developments.
The most common biobased plastics are:
1. Starch-based bio-based plastics
This category of plastics is derived from corn starch, potato starch, etc. They are sometimes mixed with biodegradable polyesters to improve the properties of the plastic. Starch is the most commonly used raw material for making biobased plastics. The creation process is simple and can also be performed as a DIY experiment in home kitchens.
Starch-based biobased plastics are used in the medical industry for the production of capsules. In addition, they are often mixed with other biopolyesters to create high-strength bioplastics that can be used for commercial applications.
2. Cellulose-based biobased plastics
These plastics are made using cellulose esters and cellulose derivatives. Cellulose is also added to starch to make biopolymers that have improved mechanical properties and are also very water resistant.
3. Protein-based bio-based plastics
Various protein sources such as wheat gluten, soy protein, milk, and casein are great sources for the production of bio-based plastics.
4. Aliphatic polyesters
Derives from the Greek aleiphatos = anointing oil, fat. There are several types of biobased polyesters, collectively known as aliphatic polyesters. Some examples of these are Polylactic Acid (PLA), Poly-3-hydroxybutyrate (PHB), Polyhydroxyalkanoates (PHA), Polyhydroxyvalerate (PHV), Polyhydroxyhexanoate (PHH) or Polyamide 11 (PA11).
5. Bio-derived polyethylene
Also known as Organic Polyethylene (PE). This is usually produced by fermenting raw materials from agricultural products such as sugar cane, corn, etc. Ethylene, the monomer that forms PE, can be recovered from ethanol and other fermented agricultural wastes. The formed bioplastic is, with regard to chemical and physical properties, comparable to conventional polyethylene.
For questions about biobased plastics, please contact us. We are happy to investigate the options for using a biobased plastic for your product.
