In the past, words like "affordable", "recyclable", "durable", "reliable" or "good processability" did not leap to mind when talking about bioplastics. But all that's changing - and changing fast. And as bioplastics continue to reinvent themselves, they are starting to make their mark on the plastics market and industry.
So, what are the major developments to keep an eye on in 2013?
One of the most important developments from the past few years has been the emergence of what are known as drop-ins, or materials produced from monomer building blocks from biomass feedstocks, that can directly replace conventional petroleum-based plastics. The carbon content of plastics produced on the basis of these biomonomers comes from renewable sources, such as plants or biowaste.
Drop-ins offer a rapid route to market through existing infrastructure and knowhow. Also, new routes are increasingly opening up, bringing the economic production of biomonomers that have the advantage of fitting easily into existing production chains, increasingly within reach.
Potentially all grades of polyethylene, polypropylene and polyvinyl chloride can currently be made via biobased routes, as can various polyamides and polyesters. In fact, a market study from the University of Applied Sciences and Arts of Hanover showed that biobased commodity plastics, with a total of around 1 million tonnes, would make up the majority of production capacity in 2015.
The race to develop 100% bio-PET, for example, accelerated this year with Coca-Cola's push to produce a 100% bio-bottle. 100% bio-based PET was successfully produced on lab scale this year; more breakthroughs in this area are expected in the year to come. In fact, according to a European Bioplastics forecast, the next few years are likely to see the largest growth in the production of biobased polyethylene and polyethylene terephthalate. The production capacity for biobased PET will continue to grow through 2016, reaching just over 4.5 million tons, or four-fifths of total bioplastic production capacity.
And, as the technology matures, the affordability of these drop-in materials, for which users must currently still pay a premium, will steadily improve.
The feedstocks used today to produce bioplastics are mainly starch or sugar derived from corn, potato, sugarcane and beetroot; in other words, from food crops. The use of arable land and edible crops to produce plastics is increasingly perceived as an undesirable development that could increase food prices and contribute to food shortages.
The coming years will see a shift from these so-called first generation feedstocks to second-generation feedstocks such as cellulosics. Cellulosic feedstocks, which consist of crop residues, wood residues, yard waste, municipal solid waste, algae or other biomass, sidestep the conflicts in land use.
They can be converted to sugars via various technologies, including enzymatic hydrolysis and biomass pretreatment. Already, cellulosic feedstocks are being used to produce, among other materials, cellulose acetates and lignin-based polymers. However, for cellulosic feedstocks to really come into their own, more, and more, sophisticated biorefineries are needed that can perform the process steps needed to produce various bioproducts. Once these are in place, a stream of non-food crop based fermentable sugars will become available for energy, chemicals and polymers.
End of life
A direct consequence of the development of biobased drop-ins is that non-biodegradable biopolymers will show the largest growth in the coming years. Whereas biodegradability and/or compostability used to be the characteristic property of bioplastics, more and more biopolymers are now being developed that instead are built to last. As a result, new or better end-of-life solutions will have to be put in place.
More landfills are not an option. An issue that needs to be addressed is that of disposing of the biopolymers being developed from new biobased monomers and polymers, such as furanic polyesters or high-heat resistant PLA. Separate collection and recycling systems are needed to ensure these do not contaminate existing waste streams. More research is needed into the possibilities for chemical and mechanical recycling of these materials. These are all issues that are on the agenda for the coming years.
Additives, modifiers, blends
Another area that will continue to develop strongly is that of biobased additives and modifiers. These are not only relevant for engineering durable biopolymers with enhanced performance properties, but also for developing less hazardous alternatives to conventional modifiers.
Concerns about the safety of the phthalates used as plasticizers in PVC and Bisphenol-A in polycarbonate, among other things, have and will continue to drive the search for more health and environmentally friendly solutions. Increasingly, biobased formulations are also being used to modify conventional materials, as these have been found to enhance the performance of these materials in various ways while at the same time improving their carbon footprint.
Metabolix, for example has developed a series of PHA-based polymeric modifiers that demonstrate very good miscibility with PVC, and improve its mechanical and environmental performance characteristics. Mitsubishi Chemical produces a polycarbonate in which the Bisphenol-A is has been replaced by isosorbide, a biomonomer that can be safely used in food applications. Isosorbide-based copolyesters are extremely promising materials that offer enhanced performance properties. PLA, blended with PMMA, enhances the processability and other properties far beyond those of conventional acrylic resins.
These are developments that may be expected to open up hitherto unimagined possibilities for biopolymers in the future.
A striking finding of a report released in October this year by European Bioplastics was that increasingly, new bioplastic production facilities are being built in Asia and South America. In fact, in 2016, Asia is predicted to be home to 46.3% of the global bioplastic production capacity. South America is projected to have nearly as much capacity in place, with just over 45%. A main driver is feedstock availability. Specifically, Thailand has expressed the ambition to become bioplastics production hub of Southern Asia, and is taking concrete steps in the form of investments and joint ventures to realize this, while in Brazil, Braskem, already the world's leading producer of bio-PE, has targeted 2013 as the year to bring its bio PP facility on stream.
Europe and North America excel at research and development, but are lagging in the production department. Andy Sweetman, chairman of European Bioplastics, pointedly remarked at the Bioplastics Conference in November of 2012 that it is time for decisions to be made if Europe wishes to profit from the growth in the bioplastics industry - a comment that also applies equally well to North America.
It's something to keep in mind for 2013.