ATMET

Figure 23. Plot of the experimental contact (Volta) potential difference atmetal/solventinterfaces ( r=0)vs. the values calculated by Jaworski898 as a function of solvent donor (DN) and acceptor (AN) numbers using the equation = 0.007 AN - 0.011 DN - 0.485. (Reproduced from...

Scheme 17 ATMET polymerization of high-oleic sunflower oil in the presence of methyl acrylate as chain stopper [115]...

ATMET of a triglyceride-based multifunctional monomer [125]. The ring opening of epoxidized soybean oil with 4-vinyl benzene sulfonic acid provided monomers suitable for metathesis polymerization. The bulk reaction of this monomer in the presence of C5 afforded a thermosetting material with a Tg of — 1.6°C. 

Atlas White Titanium Dioxide 09985] 09985 Atias White Titanium Dioxide. See Titanium dioxide Atlox 1690. See Nonoxynol-10 Atiox 4885. See Sorbitan trioleate ATM. See Trimethylaluminum Atmet 100. See Sorbitan laurate Atmet 105. See Sorbitan oleate Atmei 106. See Sorbitan trioleate Atmet 121. See Glyceryl oleate Atmet 122] Atmet 123] Atmet 125] Atmet 126] Atmet 128] Atmer 129. See Glyceryl stearate... 

Atmer 132. See Nonoxynol Atmer 1007] Atmer 1010. See Glyceryl oleate Atmer 1040, Atmer 1041] Atmer 1042. See EO/PO block polymer or copolymer Atmet 7113. See Silicone Atmos 150 K. See Mono- and diglycerides of fatty acids... 

Acyclic triene metathesis (ATMET) polymerisation is a particular ADMET application useful in vegetable oils. ADMET can also be used for the polymerisation of triglycerides, offering the possibility to obtain branched polymers directly from plant oils without prior chemical modification, thereby helping to further minimise the environmental impact of snch materials. This type of polymerisation was termed ATMET with reference to monomer functionality [51]. 

Pioneering work [52] described the ATMET reaction with a HG-II of a synthesised model triglyceride with different amounts of methyl acrylate as a chain stopper to prevent full crosslinking of the triglyceride, and to obtain branched polymers of different molecular weights in a straightforward one-step, one-pot approach (Scheme 5.13). 

Scheme 5.13 Synthesis of branched macromolecules via ATMET polymerisation...

This work involved the synthesis of branched polyols via ATMET polymerisation starting from the same model triglyceride depicted in Scheme 5.13, and its reaction with MDI to produce shape-memory PU [55]. Mn values of those polyols were 1.3-3 kDa, and the PU derived from them exhibited good thermo-mechanical properties. 

These four studies on ATMET polymerisation led to interesting macromolecules and oligomers, but only for polymers of low molecular weight. The nature of vegetable oils and the difficulty in isolating 100% pure triglycerides from them could be an impediment in development of this method. 

Another method to create new materials from polymerized plant oils is though acyclic triene metathesis (ATMET) polymerization. In this process, hyper-branched polymers are created beginning with a triglyceride that contains three alkene bonds. These hyperbranched polymers can display different physical attributes, such as lower viscosity and increased solubihty, when compared to their linear analogs. 

One problem with the ADMET and ATMET polymerization processes is the difficulty in cross-linking the polymers. Some progress has been made in obtaining polymers with unique physical properties through ADMET polymerization however, the most interesting polymers displayed the characteristics of a rubber. An alternative method to synthesizing polymers from seed oils is through... 

To obtain a branched polymer, acyclic triene metathesis (ATMET) can be used. As shown in Fig. 3.10, self-metathesis of a polyunsaturated TAG (the triene ie, triolein in the figure) would yield a hyperbranched polymer devoid of cross-links (Biermann et al., 2010). Of note, through employment of methyl acrylate as chain stopper, the resultant polymer will possess polymerizable carboxylic acid methyl ester end groups that can undergo further polymerization. 

FIGURE 3.10 Acyclic triene metathesis (ATMET) of triolein, using methyl acrylate as chain stopper. Adapted from Biermann, U., Metzger, J.O., Meier, M.A.R., 2010. Acyclic triene metathesis oligo- and polymerization of high oleic sunflower oil. Macromol. Chem. Phys. 211, 854-862. 

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