Green polymers monomers

Problem 22.34 Polylactic add (PLA) has received much recent attention because the lactic acid monomer [CH3CH(0H)C00H] from which it is made can be obtained from carbohydrates rather than petroleum. This makes PLA a more environmentally friendly polyester. (A more in-depth discussion of green polymer synthesis is presented in Section 30.8.) Draw the structure of PLA. 

Polymerization. A solution of sodium ethoxide in anhydrous ethanol is added to the stirred solution of dialdehyde monomer (4) and 2,5-bis(tri-methylsilyl)-l,4-xylene-bis(triphenylphosphonium bromide) (3) in a mixed solvent of ethanol and chloroform (1 1) at room temperature. Soon, a yellow-green precipitate forms and the mixture is stirred for 10 h after the addition. The reaction mixture is extracted with dichloromethane and water. After drying and removing the solvent, a yellow-green polymer is obtained. 

Electrochromic polymer films have been prepared by oxidative electropolymerization of the monomer tetrakis(2-hydroxyphenoxy)phthalocyaninato cobalt(II) (43). The technique involved voltammetric cycling at 100 mV s from —0.2 to -1-1.2 V vs SCE in dry acetonitrile, resulting in the formation of a fine green polymer. Cyclic voltammograms during pol5mier growth showed the irreversible... 

Synthetic Green Polymers from Renewable Monomers... 

---