Biobased polymers

Compostable plastics are those that pass the ASTM D6400 biodegradation requirements of greater than 90% carbon conversion to CO2 after 180 days while exposed primarily to hot composting conditions of 58°C and 50% moisture. Marine biodegradable plastics are those that pass the ASTM D7081 of greater than 30% carbon conversion to CO2 after 180 days while exposed to cool marine water of 30° C for 180 days. This is explained in more detail in Chapter 8. 

Biobased polymers are those made from natural or organic ingredients, such as starch from corn, potato, tapioca, rice, or wheat (Narayan 2006a, 201 lb). Biobased polymers can also be made from oils, such as palm seed, linseed, soy bean, or fermentation products, like polylactic acid (PEA), polyhydroxy alkanoate (PHA), and polyhydroxybutyrate (PHB). BPI World provides a listing of compostable plastic resins, bags, cutlery, and packaging (BPI World 2013). 

Many types of biodegradable polymers are available to biodegrade in a variety of environments, including soil, air, or compost. Biodegradable polymers are primarily made from com in the United States, but can be made from sugarcane, wheat, cellulose, collagen, casein, soy, or triglycerides. 

Material Type Resin supplier Biodegradation environment 

Bagasse Sugarcane Asean Corporation, China Various others Industrial compost 

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Biobased polymers from renewable materials have received increased attention recently. Lactate is a building block for bio-based polymers. In the United States, production of lactic acid is greater than 50,000 metric tons/yr and projected to increase exponentially to replace petroleum-based polymers. Domestic lactate is currently manufactured from corn starch using the filamentous fungus Rhizopus oryzae and selected species of lactic acid bacteria. The produced lactic acid can then be polymerized into polylactic acid (PLA) which has many applications (Hatti-Kaul et al., 2007). However, so far, no facility is built to use biomass derived sugars for lactic acid production. More research needs to be done to develop microbes using biomass derived sugars for lactate production. 

Industrial biotech represents a broad range of applications, including biobased products, bioenergy, biobased polymers, and national defense. The Department of Defense, for example, has a program to build mobile biorefineries that recycle kitchen waste. 

Figure 1. Cradle to gate, grave and cradle system of the implementation of biobased polymers obtained from renewable resources (Adapted with permission from reference 3. Copyright 2004).

Another area is the production of chemical intermediates from renewable feedstocks. Cargill-Dow and Dupont are just two of the companies beginning to market biobased polymers and plastics to replace petroleum based polymers. Again, the fermentation fundamentals originally developed for food manufacturing continue to apply to a wide variety of products. 

At room temperature, the mechanical properties of PLA are close to the one of PS but smaller than the one of PET (Table 8.5). Polyolefins present reduced stress at yield compared to PLA but the strain at break of LDPE and HOPE are much higher than the one of PLA. Compared to another biobased polymer, poly(hydroxybutyrate) (PHB), PLA shows better mechanical properties with higher modulus of elasticity and stress at yield. 

The packaging industry has been constantly looking to replace glass with polymeric materials and has recently focused on biobased polymers. However, for very delicate food products such as beer or coffee, there is a challenge to keep the freshness of the food that is related to the lowest increase of oxygen into the pack. Salame et al [207] presented the Table 8.6 and proposed a relationship that will allow a rough estimation of the shelf life t ... 

Violette Ducruet is a Senior Scientist at the National Institute for Agricultural Research (INRA), in Massy, France. In 1981, she earned her PhD in Food Science. Since 1991, she works on mass transfer between food and petrochemical packaging material implying food safety and sensorial impacts. She is involved in the characterization of the structure/barrier properties relationship of biobased polymers. 

Optical modification of PVC film with biobased polymer. [Data from Kami, Y, Weinlein, R, US Patent US20140051787, Feb. 20,20 A,Metabolix, Inc.]... 

Domburg, V., Lewandowski, I., Patel, M., 2004. An analysis and system extension of life cycle assessment studies. Comparing the land requirements, energy savings, and greenhouse gas emissions reduction of biobased polymers and bioenergy. Journal of Industrial Ecology 7 (3-4), 93-116. 

A big step in the direction of biobased polymer synthesis - moving away from petroleum and toward sugar, cellulose, starch, oils and fats, or lignin for raw materials - will definitely change the face of polymer chemistry. 

Biobased polymers or bioplastics, how they are often called, are chemical products made from monomers from plant- or crop-based resources. They have petrochemical equivalents with the same chemical structure and same properties against which they have to compete in the market. They can win this competition only through a lower price, tax advantages or governmental subsidies. 

Polylactic acid (PEA) is probably the best-known biobased polymer. It is made from glucose by fermentation to its monomer lactic acid. Two molecules of lactic acid are then condensed into the dimer lactide, which is subsequently ring-opened and polymerized to PLA in the presence of a catalyst. 

A classical example for a biobased polymer, which can be made from renewable bioproducts, is polyethylene (PE), which is nowadays produced exclusively by the catalyzed polymerization of ethylene coming directly from the steam cracker, a 100% petrochemical process. Ethylene, however, can also be produced via ethanol coming from glucose fermentation. This is a typical bio process. 

Other biobased polymer types that are currently commercially available in the market, but only in limited quantities, are either derived from starch or cellulose or produced using biotechnological instead of chemical processes. 

Figure 9.4 presents a tabular comparison of petrochemical and biobased polymers as to primary energy demand of production and GHG emissions. The savings from production of biobased polymers compared to petrochemical ones are found to be between 20 and 50GJ/t polymer and 1.0-4.01 GO2 eq/t polymer. 

Inc., and Teijin Ltd., which is known as Ingeo in the USA and Biofront in Japan. Another company, Purac, also produces biomedical application-oriented PLA-based materials under the PURASORB brand name. Figure 8.1 shows the synthesis, recycUng, and degradation of PLLA [13]. However, due to the recent initiation of the production of biobased polyethylene (PE) from bio-ethanol, PLLA is not the sole mass-produced biobased polymer. To forestall biobased PE and other biobased polymers that will be produced in the near future, high performance PLA-based materials must be developed to suppress their hydrolytic/thermal degradabiUty and increase their mechanical performance. 

Bechthold, I., Bretz, K., Kabasci, S. et al. (2008) Succmic add A new platform chemical for biobased polymers from renewable resources. Chemical Engineering and Technology. 31(5), 647-654. 

Kabasci, S. and Bretz, I. (2012) Succinic acid synthesis of biobased polymers from renewable resources, in Renewable Polymers (ed. V. Mittal), Scrivener Publishing LLC, ISBN 978-0-470-93877-S. 

Bechthold I, Bretz K, Kabasci S, Kopitzky R, Springer A (2008) Succinic acid a new platform chemical for biobased polymers from renewable resources. Chem Eng Technol 31 647-654 Berglund K, Andersson C, Rova U (2007) Process for the production of sucdnic acid. WO Patent WO/2007/046,767... 

S. Agarwal, Q. Jin, and S. Maji, Biobased polymers from plant-derived tulipalin a, in P.B. Smith and R.A. Gross, eds.. Biobased Monomers, Polymers, and Materials, Vol. 1105 of ACS Symposium Series, pp. 197-212. American Chemical Society, January 2012. 

But PLA is not suited for all applications a drawback, for instance, is that in unblended form, it softens at approximately 60°C. The biobased polymer is currently manufactured by NatureWorks LLC (United States) and Hycail (Netherlands), Mitsui Chemicals, and Toyota (Japan). 

Fig. 20.2 Schematic representation of origin and method of production of biobased polymers...

Biopolymeric nanocomposites can be easily made using nanoparticles that are derived from biobased polymers. This is an added advantage in terms of reducing inorganic content in the nanocomposites with improved mechanical properties and without affecting inherent biodegradability. 

Starch and Cellulose Biobased Polymers for Composite Formulations... 

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