Organic caibon sources

Figure 15.7 Results demonstrating that much more polymeric material can be extract by suitable organic solvents bom vulcanizates derived from polystyrene-polybutadie blends than from vulcanizates from styrene-butadiene copolymers (Shundo et al. [19 ( ) peroxide-vulcanized copolymers (O) sulfur-vulcanized copolymers (O) radi don-vulcanized copolymers (A) peroxide-vulcanized latex blends (A) sulfiir-vulcaniz< latex blends (A) radiation-vulcanized latex blends ( ) peroxide-vulcanized roll blenr ( ) sulfur-vulcanized roll blends (Qf) radiation-vulcanized roll blends. The compoun for peroxide vulcanizates and sulfur vulcanizates were as given in the cation Figure 15.6. The compound for radiation vulcanization was (parts by mass) polymer 10 calcium caibonate ICIO. Roll blending was done at 110°C. Peroxide and sulfur vulca-izatkxis were carried out at 150°C. Radiation vulcanization was achieved using 10 n from a cobaIt-60 source in air at normal ambient temperature...

Potential sources of differences in fatty acid compostion among different groups of organisms, therefore, are the use of different substrates as the chain extenders (i.e. branched vs. straight-chain compounds) and metabolic control of fatty acid chain termination. These latter are complex and regulated by a variety of nutritional, developmental and environmental factors. Chain termination mechanisms can involve P-ketoacyl-ACP synthetase specificity (from 2-16 carbons) palmitoyl-ACP P-ketostearoyl-ACP synthetase (16-18 carbons) stearoyl-(oleoyl)-CoA P-ketoeicosanoyl-CoA synthetase (18-20 caibons) FAS systems catalyzing condensation of acyl-CoA and malonyl-CoA (20-n carbons) or, for 2-carbon... 

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