Produzione di Plastica Biodegradabile da Olio di Brassica Carinata ad Alto Contenuto di Acido Erucico e da Acidi Grassi a Catena Molto Lunga

Use of materials based on fatty acids with aliph. chains of more than 20 carbon atoms, in the form or free acids or of the corresponding triglycerides, as a carbon source for the prodn. by biosynthesis, by means of microorganisms of the Pseudomonas genus, of medium chain length poly(3-hydroxyalkanoates). Very long chain fatty acids (VLCFA), longer than C20, have been employed for the prodn. of medium chain length poly(3-hydroxyalkanoates) (mcl-PHA) by Pseudomonas aeruginosa. In order to keep the prodn. costs low, Brassica carinata oil (erucic acid content 35-48%) has been employed as the intact triglyceride contg. VLCFA. As free fatty acids erucic acid (C22:1) and nervonic acid (C24:1) have been employed. The 3-hydroxyacids making up the repeating units of such polymers are satd. and unsatd., with a higher content of the latter in the case of PHAs obtained from B. carinata oil. The PHAs from erucic and nervonic acids are partially cryst., with rubbery characteristics and a m.p. (Tm) of 50°, while the increase of unsatn. degree in the repeating units of PHA from B. carinata oil affords a totally amorphous material, with a glass transition temp. (Tg) of -47°.