Polymers from triglycerides

Soybean oil is a vegetable oil dominating today s food oil market. About 80% of the soybean oil produced each year is used for human food another 6% is used for animal feed, while the ranainder (14%) serves non-food uses (soaps, fatty adds, lubricants, coatings, etc.)(Valverde et al, 2008). Another increasingly important non-food use of soybean oil is biodiesel production (in 2007 about 80% of the vegetable oil used to produce biodiesel was soybean oil in the United States). 

Soybean oil is less expensive than com, safflower, and sunflower oils. It also has a higher level of unsaturation (typical composition 53% linoleic, 21% oleic, 8% Unolenic, 10% palmitic, and 5% stearic) (Meier et al., 2(X)7) compared to some other vegetable oils. Cmde soybean oil contains approximately 95-97% triacylglycerides, making it a potential candidate as a renewable macromonomer for the polymer industry. 

The double bonds present on the fatty acid chains can undergo cationic or radical polymerization processes. The reactivity towards different polymerization techniques depends on the number and position of the double bonds hence conjugated double bonds are more reactive. Henna and co-workers (2007) prepared a copolymer of conjugated low-saturation soybean oil, acrylonitrile, and either divinylbenzene or dicyclopentadiene via free-radical polymerization. The resulting transparent yellow polymers exhibiled 10% weight loss in the dicyclopentadiene and divinylbenzene at 402-428 and 370-391 C, respectively. Complete conversion of conjugated low-saturation soybean oil was achieved when the oil concentration was kept between 40 and 65%. 

An important application of soybean oil is its conversion to polyols and use for PU foam 

Soybean oil was converted into polyols to improve its reactivity with isocyanate and used to synthesize PUs via hydroformylation and subsequent hydrogenation reactions. John and co-workers (2002) used three different polyols made from soybean oil triacylglycerides for PU synthesis with TDI and MDI and studied their reactivities and foam formation, and 

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Gallezot, P. (2007) Catalytic routes from renewables to fine chemicals. Catalysis Today, 121(1-2), 76-91. Seniha Guener, F., Yagci, Y. and Tuncer Erciyes, A. (2006) Polymers from triglyceride oils. Progress in... 

Guner, F. S., Yagc, Y., and Erciyes, A. T. Polymers from triglyceride oils. Progress in Polymer Science, 31, 633-670 (2006). 

Salunkhe DK, Chavan JK, Adsule RN, Kadam SS (1992) Wmld oilseeds chemistry, technology and utilization. Van Nostrand Reinhold, New York Seniha GN, Yusuf Y, Tuncer E (2014) Polymers from triglyceride oils. Sep Purify Technol 133 260-275... 

FIGURE 22.26 Preparation of polyurethanes from partial glycerides and hexamethylenediisocyanate (HMDI). With permission from Seniha Giiner F, Yagci Y, Erciyes Tuncer A. Polymers from triglyceride oils. Prog Polym Sci 2006 31 633-670. 

The catalytic conversion of platform molecules produced by bioconversion of renewables into bioproducts. This is already the basis of many industrial processes, leading to important tonnages of chemicals and polymers from carbohydrates and triglycerides and fine chemicals from terpenes. This approach needs to be extended and process efficiency should be strengthened by designing more active and selective catalysts. 

Implanted polymeric materials can also adsorb and absorb from the body various chemicals that could also effect the properties of the polymer. Lipids (triglycerides, fatty acids, cholesterol, etc.) could act as plasticizers for some polymers and change their physical properties. Lipid absorption has been suggested to increase the degradation of silicone rubbers in heart valves (13). but this does not appear to be a factor in nonvascular Implants. Poly(dimethylsiloxane) shows very little tensile strength loss after 17 months of implantation (16). Adsorbed proteins, or other materials, can modify the interactions of the body with the polymer this effect has been observed with various plasma proteins and with heparin in connection with blood compatibility. 

Sperling, L.H. J.A. Manson. Interpenetrating polymer networks from triglyceride oils containing special functional groups A brief review. /. Am. Oil Chem. Soc. 1983, 60, 1887-1892. 

Chee J-Y, Tan Y, Samian M-R, Sudesh K (2010) Isolation and characterization of a Burkholderia sp. USM (JCM15050) capable of producing polyhydroxyalkanoate (PHA) from triglycerides, fatty adds and glycerols. J Polym Environ 18 584-592... 

The combination with fibres has proved difficult however. Often there are issues with compatibility between bio-resins and fibres (both natural and synthetic), which cause defects in the composite structure and ultimately poorer physical properties. Castor-oil polyurethane was compared with phenolic resins when infused over sisal fibres however, the phenolic resins showed better structural performance when compared with the castor oil-based material [52]. This is not always the case, as some improvements have been made. Soybean oil thermoset polymers were used in a glass/flax hybrid composite resulting in improved mechanical performance [73], Thermoset resins were produced from triglyceride oils with a wide range of properties (tensile modulus 1-2 GPa, glass transition temperature Tg 70-120 °C) and glass- and hemp- fibre composites were manufactured [74,75]. 

Zhao, H.-P, Zhang, J.-F, Sun, X.S. and Hua, D.H. (2008) Syntheses and properties of cross-hnked polymers from functionalized triglycerides. Journal of Applied Polymer Science, 110(2), 647-656. 

Chemolysis is needed in order to free small molecules from macromolecules or polymers, such as amino acids from proteins, fatty acids from triglycerides, or sugars from polysaccharides. Specifically ... 

Figure 17.18 Monomers and polymers derived from triglycerides...

The use of epoxidized oils to prepare the SINs discussed in this paper illustrates the broad range of chemistry possible with triglyceride oils. In the past, most oils chemistry was limited to the pol mierization of the double bonds. However, research on vernonia oil (12), which also contains epoxy groups and castor oil (9), which contins hydroxyl groups, shows that many chemical derivatives of the oils can and should be used to prepare polymers from renewable resources. 

EIGURE 22.20 Polyols of a given triglyceride prepared via (a) epoxidation reaction and (b) hydrofoimylation reaction. With permission from Petrovic ZS. Polymers from biological oils. Contemp Mater 2010 I-l 39-50. 

Different polymeric materials such as alkyd resins, polyesters, and polyurethanes can be prepared from triglycerides and biodiesel after functionalization. As the synthesis of monomers and polymers from vegetable oils has several industrial applications, research in this area is widely... 

Polymers from Functionalized Triglycerides Polyesters. One of the oldest polyesters prepared from triglyceride oils are the alkyd resins. They are widely used in... 

Photosynthetic products are synthesized by plants from water and carbon dioxide, and therefore renewable monomers obtained from plants are very attractive. Though natural polymers from plants are also very attractive for the same reason, monomers are preferentially focused on in this chapter due to limitations of space (monomers obtained by digestion of natural polymers are included here). Types of renewable monomers obtained from plants without any chemical, enzymatic, and microbial conversion are limited, since plant cells are mainly composed of polymers. The principal monomer compounds that can be directly extracted from plants are oils triglycerides of fatty acids and essential oils. 

The first paints were based upon linseed oil (obtained from flax). This is an unsaturated long-chain triglyceride, which, with metal activators, crosslinks via radical pathways to form a continuous film on the substrate. Modern paints use synthetic polymers together with either a solvent or suspending medium (e.g., water), which evaporates leaving the deposited film. Exceptions are powder coatings, which require heat for completion. 

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