What is the benefit of PLA?

9 10 2018

Much of this article came from the Smithsonian Magazine written by Elizabeth Royte – to whom we owe our gratitude.

Near Blair, Nebraska is the largest lactic acid plant in the world.  Into one end goes corn, and out the other comes white pellets, which some say is the future of plastic.  The substance is PLA – Polymerized Lactic Acid, or polylactic acid.

Globally, bioplastics (of which PLA is a member) make up nearly 331,000 tons (300,000 metric tons) of the plastics market.[1]  That may sound like a lot, but it only accounts for less than 1 percent of the 200 million tons (181 million metric tons) of synthetic plastics the world produces each year. Still, the bioplastics market is growing by 20 to 30 percent each year.[2]  In the US, plastics take up 25% of landfilles by volume.[3]

Even the Biodegradable Products Institute notes that NOTHING biodegrades in a landfill because nothing is supposed to. Furthermore the Biodegradable Products Institute notes that “Uncontrolled biodegradation in a landfill can cause ground water pollution, methane gas emissions and unstable sub-soil conditions.”

The benefit of PLA is that is that it’s made from Midwestern corn, not Middle East oil[4]. It’s a renewable resource, but more than 93% of the corn produced in the USA is genetically modified in some way.  NatureWorks (owned by Cargill, the world’s largest corn merchant) insists that you don’t have to worry about consuming genetically modified proteins because these are destroyed in the transformation from plant to PLA plastic.[5]  NatureWorks, acknowledging some of those criticisms, points out that the corn it uses is low-grade animal feed not intended for human use. And it processes a small amount of non-genetically engineered corn for customers who request it.[6]

Producing PLA uses 65% less energy than producing conventional plastics, according to an independent analysis commissioned by NatureWorks. It also generates 68% fewer greenhouse gases.  And, if incinerated, bioplastics don’t emit toxic fumes like their oil-based counterparts.

PLA does releases toxicfumes known as VOCs (Volatile Organic Compounds). Not all VOCs are actually toxic, but some may be, especially for younger users. Before this becomes a serious health issue, a new study has analysed the exact quantities of toxic VOCs – as well as potentially dangerous nanoparticles – in order to assess the potential health risks. The new study, presented by Dr. Fabrizio Merlo and Dr. Eng. Stefano Mazzoni, starts off from other previous research conducted in the early 90’s, which demonstrated that during the fusion and processing of plastic materials, several toxic particles are released as gases, including ammonia, cyanidric acid, phenol, and benzene, among others.  PLA is a corn-based polymer and is not exempt from dangerous emissions, especially if extruded at temperatures higher than 200°C.  Among the effects that the absorption of toxic VOC’s and nanoparticles can cause to humans, the most common are pulmonary pathologies, such as bronchitis, tracheitis, asthma. In some cases, these substances can also cause certain types of cancers, so this is not something to be taken lightly. [7]

Another problem with PLA is that , as one of the producers, Joe Selzer a vice president at Wilkinson Industries, puts it:  “I had my takeout box in my car in the sun and it melted into a pancake!” So PLA  can’t be used for such things as containers made for holding hot liquids.   He continues: “Our number-one concern is PLA’s competitive price, and then its applications. After that comes the feel-good.”  In the beginning, it cost $200 to make a pound of PLA, now it’s less than $1.[8]

PLA produces the greenhouse gas methane when it decomposes so composting isn’t a perfect disposal method.

But the biggest problem with PLA is it’s biodegradability:  PLA is said to decompose into carbon dioxide and water in a “controlled composting environment” in fewer than 90 days. What’s a controlled composting environment? Not your backyard bin.   It’s a large facility where compost—essentially, plant scraps being digested by microbes into fertilizer—reaches 140 degrees for ten consecutive days. So, yes, as PLA advocates say, corn plastic is “biodegradable.” But in reality very few consumers have access to the sort of composting facilities that can make that happen. NatureWorks has identified 113 such facilities nationwide—some handle industrial food-processing waste or yard trimmings, others are college or prison operations—but only about a quarter of them accept residential foodscraps collected by municipalities.

Moreover, PLA by the truckload may potentially pose a problem for some large-scale composters. Chris Choate, a composting expert at Norcal Waste Systems, headquartered in San Francisco, says large amounts of PLA can interfere with conventional composting because the polymer reverts into lactic acid, making the compost wetter and more acidic. “Microbes will consume the lactic acid, but they demand a lot of oxygen, and we’re having trouble providing enough,” he says. “Right now, PLA isn’t a problem,” because there’s so little of it, Choate says.  (NatureWorks disputes that idea, saying that PLA has no such effect on the composting processes.)

To plastic processors, PLA in tiny amounts is merely a nuisance. But in large amounts it can be an expensive hassle. In the recycling business, soda bottles, milk jugs and the like are collected and baled by materials recovery facilities, or MRFs (pronounced “murfs”). The MRFs sell the material to processors, which break down the plastic into pellets or flakes, which are, in turn, made into new products, such as carpeting, fiberfill, or containers for detergent or motor oil. Because PLA and PET mix about as well as oil and water, recyclers consider PLA a contaminant. They have to pay to sort it out and pay again to dispose of it.

Wild Oats accepts used PLA containers in half of its 80 stores. “We mix the PLA with produce and scraps from our juice bars and deliver it to an industrial composting facility,” says the company spokesman Sonja Tuitele. But at the Wild Oats stores that don’t take back PLA, customers are on their own, and they can’t be blamed if they feel deceived by PLA containers stamped “compostable.” Brinton, who has done extensive testing of PLA,says such containers are “unchanged” after six months in a home composting operation. For that reason, he considers the Wild Oats stamp, and their in-store signage touting PLA’s compostability, to be false advertising.[9]

Despite PLA’s potential as an environmentally friendly material, it seems clear that a great deal of corn packaging, probably the majority of it, will end up in landfills. And there’s no evidence it will break down there any faster or more thoroughly than PET or any other form of plastic. Glenn Johnston, manager of global regulatory affairs for NatureWorks, says that a PLA container dumped in a landfill will last “as long as a PET bottle.” No one knows for sure how long that is, but estimates range from 100 to 1,000 years.

Environmentalists have other objections to PLA. Lester Brown, president of the Earth Policy Institute, questions the morality of turning a foodstuff into packaging when so many people in the world are hungry. “Already we’re converting 12 percent of the U.S. grain harvest to ethanol,” he says. The USDA projects that figure will rise to 23 percent by 2014. “How much corn do we want to convert to nonfood products?” In addition, most of the corn that NatureWorks uses to make PLA resin is genetically modified to resist pests, and some environmentalists oppose the use of such crops, claiming they will contaminate conventional crops or disrupt local ecosystems. Other critics point to the steep environmental toll of industrially grown corn. The cultivation of corn uses more nitrogen fertilizer, more herbicides and more insecticides than any other U.S. crop; those practices contribute to soil erosion and water pollution when nitrogen runs off fields into streams and rivers.

Eric Lombardi, president of the Grassroots Recycling Network and a leader in the international Zero Waste movement, takes a nuanced view of PLA’s progress. He says it’s “visionary” even to think about biologically based plastic instead of a petroleum-based one. True, he says, there are problems with PLA, “but let’s not kill the good in pursuit of the perfect.”

So in the end, what have we learned?

  • It produces no toxic compounds when burned, unlike many plastics.
  • Like conventional plastic, it’s not likely to break down in a landfill.
  • It produces methane, a potent greenhouse gas.
  • Also like conventional plastic, it doesn’t break down quickly on land or in the ocean.
  • And finally, it only can be composted in commercial-grade composting plants, while failing to break down in a backyard compost pile.

Until the kinks are worked out on the disposal and reprocessing end, PLA may not be much better than the plain old plastic it’s designed to make obsolete.

 

[1]”Bioplastics Frequently Asked Questions.” European Bioplastics. June 2008. (Nov. 6, 2008)http://www.european-bioplastics.org/index.php?id=191

[2]https://science.howstuffworks.com/environmental/green-science/corn-plastic2.htm

[3] Royte, Elizabeth; Smithsonian Magazine, August 2006

[4] Wood, Shelby,  The Oregonian; posted October 27, 2008   https://www.oregonlive.com/environment/index.ssf/2008/10/pla_corn_plastic_problems.html

https://science.howstuffworks.com/environmental/green-science/corn-plastic2.htm

[6] Ibid.

[7] https://3dprintingindustry.com; accessed on 9.28.18

[8] Ibid.

[9] Ibid.

 

 

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Bioplastics – are they the answer?

16 04 2012

From Peak Energy blog; August 27, 2008

From last week’s blog post, we discussed how bio based plastics do indeed save energy during the production of the polymers, and produce fewer greenhouse gasses during the process.  Yet right off the bat, it could be argued that carbon footprints may be an irrelevant measurement,  because it has been established that plants grow more quickly and are more drought and heat resistant in a CO2 enriched atmosphere!   Many studies have shown that worldwide food production has risen, possibly by as much as 40%, due to the increase in atmospheric CO2 levels.[1] Therefore, it is both ironic and a significant potential problem for biopolymer production if the increased CO2 emissions from human activity were rolled back, causing worldwide plant growth to decline. This in turn would greatly increase the competition for biological sources of food and fuel – with biopolymers coming in last place.[2]  But that’s probably really stretching the point.

The development of bioplastics holds the potential of renewability, biodegradation, and a path away from harmful additives. They are not, however, an automatic panacea.  Although plant-based plastics appeal to green-minded consumers thanks to their renewable origins,  their production carries environmental costs that make them less green than they may seem.  It’s important to remember that bioplastics, just like regular plastics, are synthetic polymers; it’s just that plants are being used instead of oil to obtain the carbon and hydrogen needed for polymerization.

It’s good marketing, but bad honesty, as they say, because there are so many types of plastics and bioplastics that you don’t know what you’re getting in to;  bioplastics are much more complicated than biofuels.  There are about two dozen different ways to create a bioplastic, and each one has different properties and capabilities.

Actually the term “bioplastic” is pretty meaningless, because some bioplastics are actually made from oil – they’re called “bioplastics” because they are biodegradeable.  That causes much confusion because plastics made from oil can be biodegradeable whereas some plant-based  bioplastics are not. So the term bioplastics can refer either to the raw material (biomass) or, in the case of oil-based plastic, to its biodegradability.  The problem with biodegradability and compostability is that there is no agreement as to what that actually means either,  and under what circumstances

You might also see the term “oxo-degradable”.   Oxo-degradables look like plastic, but they are not. It is true that the material falls apart, but that is because it contains metal salts which cause it to disintegrate rapidly into tiny particles. Then you cannot see it anymore, but it is still there, in the ocean too. Just as with conventional plastics, these oxo-degradables release harmful substances when they are broken down.

Let’s re-visit  some of the reasons bioplastics are supposed to be an environmental benefit:

  • Because it’s made from plants, which are organic, they’re good for the planet.  Polymer bonds can be created from oil, gas or plant materials. The use of plant materials does not imply that the resulting polymer will be organic or more environmentally friendly. You could make non-biodegradable, toxic plastic out of organic corn!
  • Bioplastics are biodegradable. Although made from materials that can biodegrade, the way that material is turned into plastic  makes it difficult (if not impossible) for the materials to naturally break down.  There are bioplastics made from vegetable matter (maize or grass, for example) which are no more biodegradable than any other plastics, says Christiaan Bolck of Food & Biobased Research.[3]  Bioplastics do not universally biodegrade in normal conditions  –  some require special, rare conditions to decompose, such as high heat composting facilities, while others may simply take decades or longer to break down again, mitigating the supposed benefits of using so-called compostable plastics material. There are no independent standards for what even constitutes “biodegradable plastic.”  Sorona makes no claim to break down in the environment; Ingeo is called “compostable” (though it can only be done in industrial high heat composters). Close studies of so-called degradable plastics have shown that some only break down to plastic particles which are so small they can’t be seen  (“out of sight, out of mind”), which are more easily ingested by animals. Indeed, small plastic fragments of this type may also be better able to attract and concentrate pollutants such as DDT and PCB.[4]
  • Bioplastics are recyclable. Because bioplastics come in dozens of varieties, there’s no way to make sure you’re getting the right chemicals in the recycling vat – so although some bioplastics are recyclable, the recycling facilities won’t separate them out.  Cargill Natureworks insists that PLA  can in theory be recycled, but in reality it is likely to be confused with polyethylene terephthalate (PET).  In October 2004, a group of recyclers and recycling advocates issued a joint call for Natureworks to stop selling PLA for bottle applications until the recycling questions were addressed.[5]  But the company claims that levels of PLA in the recycling stream are too low to be considered a contaminant.  The process of recycling bioplastics is cumbersome and expensive – they present a real problem for recyclers because they cannot be handled using conventional processes. Special equipment and facilities are often needed. Moreover, if bioplastics commingle with traditional plastics, they contaminate all of the other plastics, which forces waste management companies to reject batches of otherwise recyclable materials.
  • Bioplastics are non-toxicBecause they’re not made from toxic inputs (as are oil based plastics), bioplastics have the reputation for being non toxic.  But we’re beginning to see the same old toxic chemicals produced from a different (plant-based) source of carbon. Example:  Solvay’s bio-based PVC uses phthalates,  requires chlorine during production, and produces dioxins during manufacture, recycling and disposal. As one research group commissioned by the European Bioplastics Association was forced to admit, with regard to PVC,  “The use of bio-based ethylene is …  unlikely to reduce the environmental impact of PVC with respect to its toxicity potential.[6]

The arguments against supporting bioplastics include the fact that they are corporate owned, they compete with food, they bolster industrial agriculture and lead us deeper into genetic engineering, synthetic biology and nanotechnology.  I am not with those who think we shouldn’t go there, because we sorely need scientific inquiry  and eventually we might even get it right.  But, for example, today’s industrial agriculture is not, in my opinion, sustainable, and the genetic engineering we’re doing is market driven with no altruistic motive. 

If properly designed, biodegradable plastics have the potential to become a much-preferred alternative to conventional plastics. The Sustainable Biomaterials Collaborative (SBC)[7] is a coalition of organizations that advances the introduction and use of biobased products. They seek to replace dependence on materials made from harmful fossil fuels with a new generation of materials made from plants – but the shift they propose is more than simply a change of materials.  They promote (according to their website): sustainability standards, practical tools, and effective policies to drive and shape the emerging markets for these products.  They also refer to “sustainable bioplastics” rather than simply “bioplastics”.  In order to be a better choice, these sustainable bioplastics must be:

  • Derived from non-food, non-GMO source materials – like algae rather than GMO corn, or from sustainably grown and harvested cropland or forests;
  • Safe for the environment during use;
  • Truly compostable and biodegradable;
  • Free of toxic chemicals during the manufacturing and recycling process;
  • Manufactured without hazardous inputs and impacts (water, land and chemical use are considerations);
  • Recyclable in a cradle-to-cradle cycle.

Currently, manufacturers are not responsible for the end-life of their products. Once an item leaves their factories, it’s no longer the company’s problem. Therefore, we don’t have a system by which adopters of these new bioplastics would be responsible for recovering, composting, recycling, or doing whatever needs to be done with them after use. Regarding toxicity, the same broken and ineffective regulatory system is in charge of approving bioplastics for food use, and there is no reason to assume that these won’t raise just as many health concerns as conventional plastics have. Yet again, it will be an uphill battle to ban those that turn out to be dangerous.

A study published in Environmental Science & Technology traces the full impact of plastic production all the way back to its source for several types of plastics.[8]   Study author Amy Landis of the University of Pittsburgh says, “The main concern for us is that these plant-derived products have a green stamp on them just because they’re derived from biomass.  It’s not true that they should be considered sustainable. Just because they’re plants doesn’t mean they’re green.”

The researchers found that while making bioplastics requires less fossil fuel and has a lower impact on global warming, they have higher impacts for eutrophication, eco-toxicity and production of human carcinogens.  These impacts came largely from fertilizer use, pesticide use and conversion of lands to agricultural fields, along with processing the bio-feedstocks into plastics, the authors reported.

According to the study, polypropylene topped the team’s list as having the least life-cycle impact, while PVC and PET (polyethylene terephthalate) were ranked as having the highest life-cycle impact.

But as the Plastic Pollution Coalition tells us, it’s not so much changing the material itself that needs changing – it’s our uses of the stuff itself.  We are the problem:   If we continue to buy single-use disposable objects such as plastic bottles and plastic bags, with almost 7 billion people on the planet, our throwaway culture will continue to harm the environment, no matter what it’s made of.

The Surfrider Foundation

The Surfrider Foundation has a list of ten easy things you can do to keep plastics out of our environment:

  1. Choose to reuse when it comes to  shopping bags and bottled water.  Cloth bags and metal or glass reusable  bottles are available locally at great prices.
  2. Refuse single-serving packaging, excess  packaging, straws and other ‘disposable’ plastics.  Carry reusable utensils in your purse, backpack or car to use at bbq’s, potlucks or take-out  restaurants.
  3. Reduce everyday plastics such as sandwich bags and juice cartons by replacing them with a reusable lunch bag/box that includes a thermos.
  4. Bring your to-go mug with you to the coffee shop, smoothie shop or restaurants that let you use them. A great  way to reduce lids, plastic cups and/or plastic-lined cups.
  5. Go digital! No need for plastic cds,  dvds and jewel cases when you can buy your music and videos online.
  6. Seek out alternatives to the plastic  items that you rely on.
  7. Recycle. If you must use plastic, try to choose #1 (PETE) or #2 (HDPE), which are the most commonly recycled      plastics. Avoid plastic bags and polystyrene foam as both typically have very low recycling rates.
  8. Volunteer at a beach cleanup. Surfrider Foundation Chapters often hold cleanups monthly or more frequently.
  9. Support plastic bag bans, polystyrene  foam bans and bottle recycling bills.
  10. Spread the word. Talk to your family and friends about why it is important to Rise Above Plastics!

[1] See for example: Idso, Craig, “Estimates of Global Food Production in the year 2050”, Center for the Study of Carbon dioxide and Global Change, 2011  AND  Wittwer, Sylvan, “Rising Carbon Dioxide is Great for Plants”, Policy Review, 1992  AND  http://www.ciesin.org/docs/004-038/004-038a.html

[2] D. B. Lobell and C. B. Field, Global scale climate-crop yield relationships and the impacts of recent warming, Env. Res. Letters 2, pp. 1–7, 2007 AND L. H. Ziska and J. A. Bunce, Predicting the impact of changing CO2 on crop yields: some thoughts on food, New Phytologist 175, pp. 607–618, 2007.

[3] Sikkema, Albert, “What we Don’t Know About Bioplastics”, Resource, December 2011; http://resource.wur.nl/en/wetenschap/detail/what_we_dont_know_about_bioplastics

[4] Chandler Slavin, “Bio-based resin report!” Recyclable Packaging Blog May 19, 2010 online at http://recyclablepackaging.wordpress.com/2010/05/19/bio-based-resin-report

[6] L. Shen, “Product Overview and Market Projection of Emerging Bio- Based Plastics,” PRO-BIP 2009, Final Report, June 2009





Biopolymers and polylactic acid (PLA) – or rather, Ingeo

27 04 2011

Synthetic polymers have experienced almost exponential growth since 1950, and today about 5% of world oil production is used for that purpose.  In fact, we will need 25% or more of the current oil production for making polymers by the end of this century.

Some synthetic polymers are used to make fibers, and they have been around for a while:  rayon was discovered in 1924 and nylon in 1939.  But synthetic use really began to take off only since about 1953,  when polyester was discovered.  Qualities like durability and water resistance make synthetics highly desirable in many applications.  Today synthetics account for about half of all fiber usage.

This, despite the fact that synthetics are made from fossil fuel, and the contaminants from the manufacturing leach into our waterways and pollute the atmosphere, and the fact that they are not biodegradable and therefore don’t break down in landfills.  So recently there has been a spotlight on bio-plastics.

Bio plastics, or biopolymers –  in other words, synthetic plastics produced from biological sources –  are derived from cellulose. Cellulose is abundant – it’s said to make up half of all the organic carbon on the planet.   The most often-used biopolymers  include:

  • natural rubber (in use since the mid-1700s),
  • cellulosics (invented in the late-1800s),
  • and nylon 11 (polyamide – or PA 11) and 6–10 (polyamide 6/10) (mid-1900s).

A recent addition to the list is polylactic acid (PLA).  PLA is made from corn starch (in the United States), tapioca products (roots, chips or starch, mostly in Asia) or sugar cane (the rest of the world).[1]  You’ve probably heard about polylactic acid (PLA),  because Cargill, one of the largest agricultural firms on Earth, has invested heavily in it.  Cargill’s wholly owned subsidiary, NatureWorks, is the primary producer of PLA in the United States.  The brand name for NatureWorks PLA is Ingeo, which is made into a whole array of products, including fabrics.

The producers of PLA have touted the eco friendliness of PLA based on:

  1. the fact that it is made from annually renewable resources ,
  2.  that it will biodegrade in the environment all the way to carbon dioxide and water  –  at least in principle, and
  3. they also cite PLA’s lower carbon footprint.

Let’s take a look at these three claims.

Plant based biopolymers do come from renewable resources, but the feedstock used presents some interesting problems.  In the United States, corn is used to make the PLA. In the US, corn-based biopolymer producers have to compete with ethanol producers of government mandated gasoline blends, raising the cost and limiting availability for both. This problem will become worse in the future as the law requires a doubling of the percentage of ethanol used in motor fuel. Nearly a third of the US corn crop previously used for food was used to replace 5% of gasoline consumption in 2008.[2]

In a world where many people are starving, many say that it seems almost criminal to grow food crops, such as corn, to turn it into cloth. Agricultural lands are often cleared to make way for the growing of crops for the production of polymers. This leads to a continuous shrinking of the food producing lands of the world.  Lester Brown, president of the Earth Policy Institute, says, “already we’re converting 12% of the US grain harvest to ethanol (anticipated to rise to 23% by 2014). How much corn do we want to convert to nonfood uses?”[3]

In addition, most of the corn used by NatureWorks to make PLA is genetically modified, which raises serious ethical issues.

Other critics point to the steep environmental toll of industrially grown corn. The cultivation of corn uses more nitrogen fertilizer, more herbicides and more insecticides than any other U.S. crop; those practices contribute to soil erosion and water pollution when nitrogen runs off fields into streams and rivers.

PLA is said to decompose into carbon dioxide and water in a “controlled composting environment” in 90 days or less.  What’s that?  Not exactly your backyard compost heap!  It’s an industrial facility where microbes work at 140 degrees or more for 10 consecutive days.  In reality very few consumers have access to the sort of composting facilities needed to degrade PLA.  NatureWorks has identified 113 nationwide – some handle industrial food-processing waste or yard trimmings, others are college or prison operations .  Moreover, PLA in quantity can interfere with municipal compost operations because it breaks down into lactic acid, which makes the compost wetter and more acidic.

It looks like most PLA will end up in landfills, where there is no evidence it will break down any faster than PET.  Glenn Johnston, manager of global regulatory affairs for NatureWorks, says that a PLA container dumped into a landfill will last as long as a PET bottle.[4]

In fact, manufacturers have changed their stance: PLA is now defined as “compostable” instead of biodegradable, meaning more heat and moisture is needed to degrade PLA than is found in your typical backyard compost bin.

So far, biopolymer producers have had problems demonstrating that their materials have smaller carbon footprints than fossil fuel-derived polymers.   The energy inefficiencies of planting, growing, and transporting biological feedstocks mean more total energy is likely consumed to produce a unit of biopolymer than to make a unit of an oil or gas-based polymer.

However, Ramani Narayan of Michigan State University  found that “the results for the use of fossil energy resources and GHG emissions are more favorable for most bio based polymers than for oil based. As an exception, landfilling of biodegradable polymers can result in methane emissions (unless landfill gas is captured) which may make the system unattractive in terms of reducing greenhouse gas emissions.”[5]

Dr. Narayan recommended that, relative to their conventional counterparts, green polymers  should:

  • save at least 20 MJ (non-renewable) energy per kg of polymer,
  • avoid at least 1 kg CO2 per kg polymer and
  • reduce most other environmental impacts by at least 20%.

From this point of view, he says,  green plastics  can be defined in a broad and target-oriented manner.

But  carbon footprints may be an irrelevant measurement, because it has been established that plants grow more quickly and are more drought and heat resistant in a CO2 enriched atmosphere. Many studies have shown that worldwide food production has risen, possibly by as much as 40%, due to the increase in atmospheric CO2 levels. Therefore, it is both ironic  and a significant potential problem for biopolymer production if the increased CO2 emissions from human activity were rolled back, causing worldwide plant growth to decline.  This in turn would greatly increase the  competition for biological sources of food and fuel –  with biopolymers coming in last place.[6]

A further problem with biopolymers (except for future PE/PP made from sugar cane) is that  they require additional sorting at commercial recycling centers to avoid contaminating other material streams, and, although segregated collection helps, it is complex and increases costs.

In the final analysis, newer biopolymers don’t yet perform as well as oil based polymers, especially in terms of lower heat and moisture resistance, so the user might feel green but gets results that are less sustainable and more limited in use.  PLA remains a boutique polymer, and some see the best value proposition for biopolymers to be where their use is based on their unique properties, such as in medical and dental implants, sutures, timed released chemotherapy, etc. , because  PLA will slowly come apart in the body over time, so it can serve as a kind of scaffold for bone or tissue regrowth or for metered drug release.  But this is a small and specialized market.

But still, the potential and need for plastic alternatives has become acute:  The SPI Bioplastic Council anticipates that the biopolymer market will exceed $1 billion by 2012 – today it is half that.   Bioplastic remains “a sector that is not yet mature but will be growing fast in the coming years,” says Frederic Scheer , CEO of Cereplast and the so-called ‘Godfather of Bioplastics.’  It has not matured because of high production costs and the restricted capacity of biomass-based polymers.

But  according to The ETC Group, there are already concerted efforts, using biotechnology,  to shift global industrial production from a dependence on fossil fuels to biomass – not only for plastics but also for power, chemicals, and more.  It sounds good – until you read their report, which I’ll cover next week.


[2] Jones, Roger, “Economics, Sustainability, and the Public Perception of Biopolymers”, Society of Plastics Engineers, http://www.4spepro.org/pdf/000060/000060.pdf

[3] Royte, Elizabeth, “Corn Plastic to the Rescue”, Smithsonian,  August 2006

[4] Ibid.

[5] Narayan, Ramani, “Review and Analysis of Bio-based Product LCA’s”, Department of Chemical Engineering & Materials Science, Michigan State University, East Lansing, MI 48824

[6] D. B. Lobell and C. B. Field, Global scale climate-crop yield relationships and the impacts

of recent warming, Env. Res. Letters 2, pp. 1–7, 2007  AND

L. H. Ziska and J. A. Bunce, Predicting the impact of changing CO2 on crop yields:

some thoughts on food, New Phytologist 175, pp. 607–618, 2007.