Bio-based polymer

To deal with depleting oil reserves, one possible strategy is to prodnce bio-based polymers, whose current sustainabihty is generally lower than their oil-based counterparts, but interestingly come fiom renewable materials, often from plants [ALV 12], Polymers made of plants can be used as bags at checkouts, food punnets, surfactants or even as reinforcements (flax, hemp, wood, etc ). 

The plant kingdom may have future potential in the fields of chemistiy, energy and renewable materials. Non-food crops prevent the annual importation of hundreds of thousands of tons of oil, and, in the field of macromolecules, they can provide natural monomers, surfactants, stabilizers and polymers. 

Generally speaking, numerous synthons can be extracted from biomass. One known example is that of ethylene, produced from the dehydration of ethanol which is a very common product of fermentation. Another example is 1,3-propanediol, which is a monomer used as a building block for the production of polymers such as polyesters and polyurethanes. Several industrial processes have studied its production by fermentation with the aim of producing it directly from inexpensive plant raw materials (starch or sucrose). To synthesize polyamides and polyesters, we also aim to produce a,(o-dicarboxylic acids by the biological conversion of esters from vegetable oils. 

Biopolymers can be directly obtained [KOB 03] fiom hemicellulose in com or starch. Starch, a major polymer from arable crops, is a good candidate for the production of biodegradable packaging or objects. If combined with a compound of wheat straw, its potential apphcations could increase. 

Over the past few years, the production of polymers from renewable resources has rapidly increased at the industrial scale. Cargill-Dow has an industrial plant for the production of biodegradable PLA, which has a high-molar mass PRU 00]. Major chemical companies and downstream industries are all preparing for these changes [MAS 06]. 

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Milne WGA (1995) Handbook of pesticides. CRC Press, Boca Raton, FL Mohanty AK, Drzal LT, Misra M (2003) Nano reinforcements of bio-based polymers—the hope and the reality. Polymeric Mater Sci Eng 88 60-61 Montgomery JH (1993) Agrochemicals desk reference Environmental data. Lewis Publishers, Chelsea, MI... 

Yoon, J.S., Im, S.S., and Chin, I. 2005. Bio-Based Polymers Recent Progress. Wiley, Hoboken, NJ. 

Blends of polymers from renewable resources with Ecoflex (see Fig. 4), however, show very beneficial properties with respect to processability and mechanical characteristics. Thus, Ecoflex is used as a performance enabler for biopolymers, making it possible to apply bio-based polymers to a certain extent in applications for which the pure renewable materials are not suitable. 

Textbook Bio-based Polymers Composites Academic Press Richard Wool... 

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. 

For example, if we consider the set of biodegradable and/or bio-based polymers, a recent market study published by the organization European Bioplastics (http //en.european-bioplastics.org/) shows that world capacity for production of these polymers, in 2012, was only around 1.4 million tons, of which 0.6 milhon were accounted for by biodegradable polymers. Compare this with worldwide plastic consumption of 288 million tons, of which, 57 million tons were in Europe alone, according to Plastics-Europe (http //www.plasticseurope.org), in 2012. Recent projections - particularly that presented by European Bioplastics - show that these very rapidly growing polymers will, nevertheless, remain a niche market for the next 10 years. They will account for only a small percent of the world plastic market. Thus, it is not envisaged that these polymers can totally replace conventional plastics. 

Biodegradable and bio-based polymers are, however, an interesting approach,... 

Figure 9.2. Lifecycle of biodegradable and bio-based polymers (example starch)...

We can classify the different biodegradable and bio-based polymers into two major families agropolymers (categoiy a) and biodegradable polyesters (categories b and c). To illustrate the latter, the next section focuses on the description of biodegradable polyesters, from synthesis to application. 

Figure 10.4. Comparison of energy consumption and CO2 emissions of the oil-based polymers (poly(ethyleneterephthalate) PET, poly(styrene) PS andpoly(ethylene) PE), and the bio-based polymers (poly(hydroxybutyrate) PHBB, poly(butylene succinate) PBSC and starch-poly(caprolactone) SPCL) [PAT 05]...

RAVll] Ravenstjin J., Bio-based polymer a revolutionary change, http // www.jeccomposites.com/news/composites-news/bio-based-polymers-revolutionary-change, 2011. 

LCA of fibre-reinforced composite materials has helped to better characterise composite products, in terms of environmental performance, and compare them with other classes of materials. Generally, LCAs of bio-based polymer composites have shown favourable results in terms of environmental impacts and energy use compared to petroleum-based products (Corbiere-Nicolher et al., 2001 Domburg et al., 2004 Gonzalez-Garcia et al., 2010 Wool and Sun, 2005). However, calculation of these impacts always depends on the system and boundary conditions considered during the study. 

Wool, R.P., Sun, X.S., 2005. Bio-based Polymers and Composites. Elsevier Science Technology Books, ISBN 0127639527. 

Stefano Farris, Karen M, Schaich, LinShu Liu, and LP, Yam KL. Development of polyion-complex hydrogels as an alternative approach for the production of bio-based polymers for food packaging applications A review. Trends in Food Science and Technology. 2009 20 316-332. 

Over the past decade, researchers and citizen advocates have developed several tools to assist in decision making about plastics selection. The plastics pyramid (Fig. 5.1] developed by Thorpe and Van der Naalde in 1998 was an early attempt to visually display the life cycle hazards of different plastics to assist in materials selection. This ranking focused on the toxicity of the material, considering production hazards, use of harmful additives, hazards in use, and disposal hazards. In this pyramid, bio-based polymers form the bottom of the pyramid, indicating they are most preferable, as they are made from renewable resources, and theoretically are biodegradable and compostable (Rosalia et al., 2012]. 

Crank, M., Patel, M., Marscheider-Weidemann, E, Schleich, J., Heusing, B., Angerer, G. (2005). Techno-economic Feasibility of Large-scale Production of Bio-based Polymers in Europe, in (Wolf, 0., ed.). Technical Report Series, European Commission, EUR 22103 EN. 

The bio-based polymer and composites open new windows for becoming independent from petrochemical-based polymers and also free of environmental and health concerns. 

PHA is a very promising polymer for a wide range of applications that can be accumulated from multiple microbial sources cultivated on number of media. In comparison with other bio-based polymers such as PLA, it has better barrier and mechanical properties. To overcome its brittleness as well as improve its processability, PHB... 

More bio-based polymers are in the chemical industry s pipeline for all performance specifications from commodities and engineering up to high-performance polymers. Biotechnology restarted the innovation cycle which stopped for petrochemical polymers 15 years ago (Figure 12.4). 

Wool RP, Sun XS (2004) Bio-based polymers and composites. Elsevier, Amsterdam... 

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