Take-out in boxes fermented from bacteria, ketchup squeezed from seaweed, oil spills cleaned with aerogels derived from wood pulp- these seeming technologies of the future are already being commercialized by bioplastics start-ups today. Transitioning out of a fossil-based plastic world has already started and materials of the future are being grown. As single-use plastic bans are implemented around the world, companies are searching for materials that can replace these plastics with minimal compromise to quality and performance. They are looking for a material that not only acts like a plastic but also, critically, comes from a renewable source and, after its use, can be broken down sustainably. That has led many to look for solutions in the natural world, biology that has already evolved polymers that are both renewable and biodegradable. Today, there are many natural polymer startups breaking into the industry and in this article, IDTechEx explore three promising naturally occurring materials.
First, this article will look at the most abundant polymer in nature: cellulose. Cellulose is the polymer that makes up the fiber in every plant and is already used, from paper to textiles. A new class of cellulose called nanocellulose, tiny fibers at the micro and nano scale, has been researched for its exceptional material properties and has now begun to commercialize. These tiny fibers are so small that they create a massive surface area, making the material form a tight network of fibers giving a stiffness comparable to Kevlar as well as excellent gas barrier properties. Such properties make nanocellulose useful in major applications such as packaging and coatings. The material can also be used to stabilize emulsions in personal and cosmetics applications. Perhaps the most exciting application may come from the ability for nanocellulose to be aerogels with superior absorption properties, and it has been suggested that they could clean up oil spills as super sponges of the future. Most importantly, the stuff is cheap to make. Trees are abundant, and that makes nanocellulose a suitable substitution for many fossil-based plastics today.
But there is one major constraint with nanocellulose: due to the high surface area of the fibers, dry nanocellulose likes to clump together and becomes all but impossible to break down. So, the material is transported dispersed in water as a gel or paste, and that means transporting tons of water weight, a nightmare for the cost of logistics. To remedy this problem, some producers are developing techniques to make the material as a dry powder by coating them to prevent clumping. IDTechEx discusses the applications and technologies of nanocellulose and compares the different forms of nanocellulose as part of their recent report, "Bioplastics 2023-2033: Technology, Market, Players, and Forecasts".
One of the natural polymers with the most attention and development today are polyhydroxyalkanoates (PHAs). PHAs are a family of materials that are produced by a variety of microorganisms via fermentation. These materials were described over a century ago, but only in recent years has it been feasible to produce the materials at a commercial scale. The properties of the material range from amorphous to hard and brittle depending on the chain length of the PHA, whether long or short. Compounders can blend different PHAs alongside other additives to create a spectrum of materials that grant PHAs incredible versatility. The future could see fermenting the material for our packaging, utensils, even sunglasses, and 3D printing filaments! There are several projects involving multinational companies such as Pepsico, Nestle, Nike, and Mars, which are exploring the myriad uses of these materials.
PHAs were expensive to produce years ago. In 2003, the cost of PHA was as high as US$20 per kg, attributed to the batch-to-batch nature of production and the need to break open cells to extract and then purify the material. But since then, this has dropped at an incredible pace as production capacity grows. Today, PHAs can cost below US$3 per kg. Technical advancements continue to push costs down as well as improve the sustainability of processing techniques; however, some problems face the industry. PHAs are a sensitive material, they have a low melting temperature and are susceptible to shear force, this is something that compounders need to adapt their technology for. Other technical challenges are being addressed by producers to make PHAs more cost-competitive and to improve the quality of the product. But the biggest problem for the European market, in particular, is that EU legislators do not classify PHAs as a natural material, and as such, they are not exempt from the single-use plastic ban, preventing the use of biodegradable and renewable materials in this very suitable type of application. Overall, the PHA industry has moved from embryonic into early-phase growth; IDTechEx reports on the industry activities and technologies driving the growth of the PHA market in their report "Bioplastics 2023-2033: Technology, Market, Players, and Forecasts".
Seaweed as a plastic packaging alternative has been gaining traction as an alternative to fossil-derived plastics. There are several advantages to seaweed material for packaging. First, the material is a renewable source that does not compete for food agriculture land nor requires the use of fertilizers. Beyond this, seaweed is not only food safe but also has antioxidant and antimicrobial properties, which make it a strong candidate for food packaging. Several proof-of-concept studies have demonstrated that seaweed-based films have been able to extend the shelf-life of foodstuffs by reducing water vapor permeability and limiting microbial activity. Players have partnered with brand owners like Heinz and JustEat to make seaweed-based condiment sachets and paper box coatings. Yet the market for seaweed material is still very early with few players and very little capacity, causing prices to remain high compared to incumbent plastics. That may be remedied with business models such as licensing out seaweed packaging production with turnkey solutions directly at the restaurant or store.
These natural materials may well displace fossil-based plastics in the future in major applications like packaging and single-use items. While they remain some distance away from producing commercial capacities, their growth in coming years could be meteoric. IDTechEx's recent report "Bioplastics 2023-2033: Technology, Market, Players, and Forecasts" includes detailed analysis of how these natural materials are breaking into the plastics world, alongside synthetic biobased materials. It tracks the huge industry activity that has been happening and discusses the trends and challenges surrounding bioplastics, considering these in a comprehensive 10-year forecast. Find out more about the outlook of our bioplastic world by visiting the report at www.IDTechEx.com/Bioplastics.