Biopolymers - Food and Industrial Bioproducts and Bioprocessing - page 275

good interfacial adhesion. A different approach to synthesize polyols for PU synthesis from
canola oil was utilized by Petrovi´ and co-workers (2005). Ozonolysis of canola oil yielded
polyols with terminal primary hydroxyl functionalities in a similar fashion as already
discussed for soybean oil.
High oleic sunflower oil (HOSO) contains a minimum of 80% (up to 93%) oleic acid that
makes it especially attractive for certain synthetic applications. Lluch and co-workers (2010)
synthesized a triacylglyceride derivative containing allylic alcohol groups via direct photo-
peroxidation of HOSO in the presence of singlet oxygen followed by reduction with sodium
borohydride. This derivative was acrylated and cross-linked via radical polymerization. The
extensive hydrogenation of this derivative, prior to acrylation and radical polymerization,
led to an improvement of the thermal stability of the cross-linked polymers. In both cases,
highly cross-linked thermosets were obtained.

11.3.2 Polymers from fatty acids
Today, plant oils represent the major renewable resource for the chemical industry, offering
broad possibilities for polymer production (Metzger and Bornscheuer, 2006). Plant oils
offer a number of fatty acids with different chain lengths and functional groups as well as
different numbers and positions of C = C double bonds that can be transesterified with an
alcohol, mainly methanol (Figure 11.9). Since plant oils consist mainly of triacylglycerides
of various saturated and unsaturated fatty acids, it is difficult to synthesize structurally
well-defined and property-tailored polymers. As a result, fatty acids serve as valuable

O

OH

O

O

O

O

O

O

O

O

O

O

O

O

O

O

Figure 11.9 Chemical structure of the most widely applied fatty acid methyl esters.