By: Malcolm Harold
Polyesteracetals represent a new class of green plastics which are produced from sustainable biomass sources and are degradable back into ecological life cycles. This technology is particularly amenable to the market segment of disposable packaging and consumer products. Polyesteracetals possess two main strengths which specifically differentiate them from other players in this sector:
1) Multiple Sustainable Production Routes: Polyesteracetals can be produced from two major ecological sources, either directly from C1 feedstocks (small organic molecules rapidly produced biologically or geologically, such as methanol), or through fermentation methods (such as through fermentation of plant matter).
2) Multiple Degradation Routes: Polyesteracetals are able to degrade through multiple routes, due to the incorporation of both ester groups and acetal groups.
We are all familiar with the success of PLA used for disposable cups, snack bags, plasticware, bottles and films, A major drawback to this material is that it is derived from starch, which is relatively expensive and preferentially a food source. Another major drawback is its comparatively low glass transition temperature (Tg, the temperature at which the material deforms) that precludes its use for hot food or hot beverage contact. Because of this thermal limitation, it is not a universal replacement for the ubiquitous packaging material polystyrene. Despite the societal push, marketing, and visibility of PLA products, the worldwide demand for PLA is only about 60 million kg/year, which amounts to approximately 0.03% of the annual worldwide synthetic polymer output. Cargill Dow has predicted a possible market of 3.6 billion kg/year by 2020 (http://www.biorefine.org/prod/lac.pdf), which would potentially be about 1% of the global synthetic polymer market (nearly 250 billion kg/year today). Even to capture just 0.25% of the global plastics market would represent £700,000,000 annually. Indeed, there is much room for growth in the sustainable plastics industry.
The current technology, Polyesteracetals (PEA), developed at the University of Florida, fills the technological gaps left by PLA with the use of novel and patent-pending materials and methods utilizing inexpensive and bio-renewable feedstocks. The starting materials can be industrially produced in >99% yield from trioxane and carbon monoxide. PEA does not suffer from the same drawbacks as PLA. PEA is made from inexpensive C1 feedstocks and does not require expensive fermentation processes like PLA does. PEA thermal properties are on par with traditional commodity thermoplastics. Unlike PLA which is limited to degrade primarily from acid hydrolysis of the ester groups, PEA can degrade through various biological and chemical mechanisms due its incorporation of both ester groups and acetal groups.
PEA can be used as either a stand-alone homopolymer material, or can be used to create commercially-attractive copolymers with PLA. Even with a small incorporation (approximately 3%) of PEA into the PLA chains, the properties of PLA are markedly improved. PLA/PEA copolymers (which is affectionately called “PLA 2.0”) shows an increase in Tg of 15 °C and an increase in thermal stability of 20 °C , as well as giving films of a the material a clearer optical appearance. This allows for a greater range of uses and makes transportation easier and cheaper. Not only are thermal and optical properties improved, but degradation of the polymer is greatly enhanced. Our “PLA 2.0” has been shown to degrade roughly 10 times faster than commercial PLA. For example, when a sample of commercially available PLA was stirred in seawater for an extended time period, data indicate that the sample would require approximately 50 years to completely break down. This is in stark contrast to the results of the same test run our material. PLA 2.0 would require just under 5 years to completely break down under the same conditions. This is very significant.
Also notable is the fact that PEA is made using the same mechanism, conditions, and equipment as PLA. PEA and PLA/PEA copolymers could be produced using existing facilities with little or no modification.
Films made from all PLA (left) frequently suffer from brittleness and poor clarity. The PEA film (right), made under the same conditions, clearly addresses these problems.
As consumers become more aware of global sustainability issues, their demand for environmentally-friendly products increases as well. The biodegradable plastics market is projected to grow over 15% per year in the near term and polyester -based materials —specifically PLA—will grow most rapidly (http://www.freedoniagroup.com/Biodegradable-Plastic.html). A 2008 survey conducted by Market Tools, Inc. was titled “U.S. Consumers Willing to Buy Renewably Sourced Products” and stated that 75% of households claim to be “environmentally responsible”. Moreover, 65% of respondents are willing to pay more for renewably sourced (corn, sugar beets, etc.) products, 40% are willing to pay at least a 10% premium, and 3% are willing to pay a 50% premium.
As is true for all new packaging polymers, the initial cost considerations are very high compared to mature products in the industry. While PLA ($1.30/lb.) is now reasonably cost-competitive with PET ($0.70/lb.) or high impact polystyrene (HIPS, $0.50/lb.) (http://www.ptonline.com/articles/renewable-pla-polymer-gets-‘green-light’-for-packaging-uses), this was not always the case. PLA began at a price at least an order of magnitude greater and economies of scale have brought it down to the current level. There is huge momentum in the various packaging markets, but PLA, for example, has shown that change is possible. Entering the global $400 billion/year packaging industry is challenging, but even a fractional market share translates into a rather sizeable company.
At this time, scientists and market development managers at PepsiCo, DuPont, Invista, TenCate, Dow Benelux, Alpla, and Coca-Cola have been engaged. Professor Miller visited PepsiCo world headquarters in October, 2010, and PepsiCo has completed a non-disclosure agreement regarding this technology.
Additional strategic partners will be sought in the country of Indonesia. Professor Miller was recently invited to be the U.S. delegate/speaker for the “Biodegradable Plastics, Solution for Future Eco-Materials” session at the inaugural U.S./Indonesia National Academy of Sciences/Kavli Symposium, to be held in Bogor, Indonesia, July 7th-1 2th , 2011. These Kavli Symposia have diverse attendees, are highly interactive, and are scheduled with extra time to facilitate scientific interactions and off-site visits.
3) Magic (IP Protection)
The Miller Research Group investigates the synthesis of a wide variety of sustainable polymers. Novel inventions become the property of the University of Florida. The University of Florida Office of Technology & Licensing filed a Provisional Patent Application for the present invention on December 4, 2008, and PCT application for a full utility patent one year later, International Application No. PCT/US2009/0664 17.
Academic inventors hoping to gain footing in the immense packaging plastics arena must partner with a large polymer production company in order to be noticed and have any significant impact. Professor Miller continues to seek strategic partners who will fully appreciate the massive potential of this invention and have the capacity to act on it. There are not many companies that fit this description, but market forces and peer pressure seem to be directing many companies toward more sustainable operating models.
While several projects are being pursued in the Miller Research Group at UF devoted to new green plastics, the Polyesteracetal project is furthest along and represents a technology that is most ready for market.
- The chemistry is simple and sound.
- Prototypes have been made, including durable and clear films (Indeed, many polymers do not lend themselves to being made into films like this).
- Thermal and degradation studies have been performed, with outstanding results.
For more information on PEA please contact Professor Miller:-
Tags: biocomposite, Biodegradation, bioplastic, biopolymer, Business, Material, Materials, Materials and Supplies, new products, packaging, PepsiCo, Polymer, Research and development, Technology, University of Florida
This entry was posted on Tuesday, July 19th, 2011 at 12:30
You can follow any responses to this entry through the RSS 2.0 feed.