Soybean oil-based polymers

More recently, a variety of exciting new polymeric materials have been prepared in our group by the cationic copolymerization of soybean and other vegetable oils with a variety of alkene comonomers 18-35). These biopolymers possess industrially viable thermophysical and mechanical properties and thus may find structural applications. This chemistry takes advantage of the original C=C bonds of the soybean 18-27), tung 28,29), corn 30) and fish oils 31-35) to effect crosslinking. In this chapter, we shall focus primarily on the synthesis and characterization of soybean oil-based polymers, which result from the direct copolymerization of the C=C bonds of soybean oils with other comonomers via cationic polymerization 18-27). 

Table II. Summary of the Properties of Soybean Oil-Based Polymers...

Javni, L W. Zhang Z.S. Petrovic. Soybean-oil-based polyisocyanurate rigid foams. /. Polym. Environ. 2004,12, 123-129. 

Liu, Z.S. S.Z. Erhan J. Xu P.D. Calvert. Development of soybean oil-based composites by solid freeform fabrication method Epoxidized soybean oil with bis or polyalkyleneamine curing agents system./. Appl Polym. Sci. 2002, 85, 2100-2107. 

Nayak, R.R. G. Ray B. Guru S. Lenka. Comparative studies of interpenetrating polymer networks derived from soybean oil-based polyurethane and cardanol m-aminophenol dye. Polym-Plast. Technol. 2004, 43, 261-272. 

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]. 

Fu, L., Yang, L., Dai, C. elal. (2010) Thermal and mechanical properties of acrylatedexpoxidized-soybean oil-based thetmosets. Journal of Applied Polymer Scierute, 117(4), 2220-2225. 

L. Fu, L. Yang, C. Zhao and L. Ma, Thermal and mechanical properties of acry-lated expoxidized-soybean oil-based thermosets , J Appl Polym Sci, 2010,117, 2220-2225. 

The effect of loading (0.5,1.0 and 2.0 wt%) nanostructured polyaniline (PANI) on the physiochemical, physicomechanical, morphological and thermal properties of soybean oil-based polyester nanocomposites has also been reported. The nanocomposites of conjugated linseed oil, acrylic acid and divinylbenzene are synthesised using modified montmoriUonite clay. The resultant nanocomposites exhibit a storage modulus in the range of 17-79 MPa at the glass transition temperature compared to the pristine polymer which is 2.1 MPa. The nanocomposites show better thermal stability (up to 200°C) than the pristine polymer. 

Triglycerides, Soybean oil. Castor oU, Sunflower oil. Oil-based polymers. Fatty acids, Epoxidized oils. Interpenetrating networks, CrossUnking of oils. Oil-based polyurethanes, OU-hased polyamides. Oil-based polyester-amides. Oil-based alkyd resins. Oil-based polyesters. Oil-based poly(hydroxyalkanoates)... 

Soybean, fish, com, tung, linseed and castor oils are the most common renewable resources used as precursors for the synthesis of vegetable oil-based polymers. Their composition in fatty acid is shown in Table 3.3 [3, 17]. The chemical structures of the most representative oils in these families are given in Scheme 3.2. 

L. Zhang, H. K. Jeon, J. Malsam, R. Herrington, and C. W. Macosko, Substituting soybean oil-based polyol into polyurethane flexible foams. Polymer 48,6656-6667 (2007). 

Considerable recent effort has been directed towards the conversion of vegetable oils into solid polymeric materials. These vegetable oil-based polymers generally possess viable mechanical properties and thus show promise as structural materials in a variety of applications. For example. Wool and coworkers have prepared rigid thermosets and composites via free-radical copolymerization of soybean oil monoglyceride maleates and styrene (10-12). The new maleate monomers are obtained by glycerol transesterification of soybean oil, followed by esterification with maleic anhydride (10). It has been... 

In 2008, Biswas and co-workers reviewed nitrogen containing monomers, for example fatty amines, fatty amides, fatty imidazolines, and polymers (PUs) made from soybean oil-based... 

Although plant oil-based polymers are mainly derived from soybean and castor oil, an ever increasing number of publications are devoted to the use of other plant oils, such as linseed oil, tung oil, canola oil, high oleic sunflower oil, and many others. 

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