Polyesters from plant oils

Ecoflex ES was commercialized by BASE in 2010 as a compound with poly(lactic acid) (PEA) (Ecovio ES see Sect. 4.2.2). Ecoflex ES is an aliphatic-aromatic polyester with a similar structure to that of Ecoflex E (see Eig. 3). However, through exchanging one of the monomers with a monomer derived from plant oil, the new Ecoflex ES is partly based on renewable resources. 

Such development has justified the significant industrial investment made by Novamont to build the first local biorefinery of this type in Europe, which comprises plants for the production of nanostructured starch and polyesters from vegetable oils. Moreover, new investments on monomers from vegetable oils from local crops will permit a further up-stream integration of the biorefinery. 

Biodegradable polymers that are based on renewable resources include polyesters such as polylactic acid (PLA) and polyhydroxyalkanoate (PHA). Biodegradable polymers can also be made from extracts from plants and vegetables such as corn, maize, palm oil, soya and potatoes. 

Biodegradable polymers can also be made from mineral oil based resources such as the aliphatic-aromatic co-polyester types. Mixtures of synthetic degradable polyesters and pure plant starch, known as starch blends, are also well-established products on the market. 

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. 

As a possible application of glycerol-based polyesters, new crosshnkable polyesters were synthesized via a lipase CA-catalyzed polymerization of divinyl sebacate and glycerol, in the presence of unsaturated higher fatty acids derived from renewable plant oils [110, 111]. The curing of the polymer obtained from hnoleic or hnolenic acid proceeded via a cobalt naphthenate catalyst or thermal treatment to produce a crosshnked transparent fUm with good biodegradabiHty. 

The session Polymer from Biomass included 8 oral presentations. These presentations were devoted to the problems of production (synthesis) polymers from biomass particularly sustainability assessment of polymers based on renewable resources novel cellulose based materials and processing routes biomass-based polyesters and polycarbonates for coating and engineering plastic applications plant oils as renewable resources in polymer science. 

This chapter focuses on the preparation of thermosets, polyesters, and other polymers from industrial oilseeds. Nature has provided a few examples of plant oils that possess multiple functional groups needed for polymer synthesis, such as castor (Ricinus communis), lesquerella (Lesquerella fendleri), and vemonia (Vernonia galamensis) oils, enriched in —OH and epoxide-functionalized fatty acids ricinoleic, lesquerolic, and vemolic acid, respectively (Table 3.1). Many common plant seed oils (eg, soybean, cottonseed, com, soybean, safQower, sunflower, canola, jatropha, and olive oils) are enriched in Ci6—Cig saturated and mono- and diunsaturated fatty acids, such as palmitic (16 0), oleic (18 l-9c), and linoleic (18 2-9c,12c) acids and lesser amounts of a-linolenic acid (18 3-9c,12c,15c) however, linseed (flaxseed), camelina (Camelina saliva). 

Ricinoleic acid (i -12-hydroxy-9-cw-octadecenoic acid) (Fig. 6) accounts for 80-90% of fatty acids in castor oil (from Ricinus communis). It is found in other plant species and in the sclerotia of the ergot fungus Claviceps purpurea). Lesquerolic acid (i -14-hydroxy-ll-cw-eicosenoic acid), which is a C20 homolog of ricinoleic acid, occurs in Lesquerella species (up to 70% of total fatty acids). Isoricinoleic acid (i -9-hydroxy-12-cw-octadecenoic acid, or 9-OH 18 2 12c) is a major acid in the Wrightia species. In plants, several C16 and C18 mono, di, and trihydroxy fatty acids are stmctural components of cutin (a polyester constituent of plant cuticle). 

The biochemical reaction catalyzed by epoxygenase in plants combines the common oilseed fatty acids, linoleic or linolenic acids, with O2, forming only H2O and epoxy fatty acids as products (CO2 and H2O are utilized to make linoleic or linolenic acids). A considerable market currently exists for epoxy fatty acids, particularly for resins, epoxy coatings, and plasticizers. The U.S. plasticizer market is estimated to be about 2 billion pounds per year (Hammond 1992). Presently, most of this is derived from petroleum. In addition, there is industrial interest in use of epoxy fatty acids in durable paints, resins, adhesives, insecticides and insect repellants, crop oil concentrates, and the formulation of carriers for slow-release pesticides and herbicides (Perdue 1989, Ayorinde et al. 1993). Also, epoxy fatty acids can readily and economically be converted to hydroxy and dihydroxy fatty acids and their derivatives, which are useful starting materials for the production of plastics as well as for detergents, lubricants, and lubricant additives. Such renewable derived lubricant and lubricant additives should facilitate use of plant/biomass-derived fuels. Examples of plastics that can be produced from hydroxy fatty acids are polyurethanes and polyesters (Weber et al. 1994). As commercial oilseeds are developed that accumulate epoxy fatty acids in the seed oil, it is likely that other valuable products would be developed to use this as an industrial chemical feedstock in the future. 

Biodegradable plastics can be based on natural or synthetic resins. Natural biodegradable plastics are based primarily on renewable resources (such as starch) and can be either naturally produced or synthesized from renewable resources. They are coming under polysaccharides (starch, cellulose, lignin, etc.), proteins (gelatine, wool, silk, etc.), lipid (fats and oil), polyesters produced by plant or microorganisms (PHA), polyesters derived... 

---