Poly-alcohols Proline

The intrinsic viscosity of poly(L-proline) is studied as a function of molecular weight and temperature In five commonly used solvents water, trifluoroethanol, acetic acid, propionic acid, and benzyl alcohol. The characteristic ratio is 14 in water and 18-20 in the organic solvents at 303 K, and d (in 0) / d T is negative. The theoretical rotational potential function obtained by Hopfinger and Walton for u-prolyl-L-prolyl-t-prolyl-t-proline J. Macromol. Scl. Phys. 1969, 3, 171 correctly predicts the characteristic ratio at 303 K but predicts the wrong sign for tfiln < >0) IdT. 

The case of UCST > LCST is observed with water-soluble polymers. Examples of these are poly(vinyl alcohol) (see Figure 6-14), poly(vinyl methyl ether), methyl cellulose, and poly(L-proline). The heating of aqueous solutions of these polymers causes a decreasing solvation of the polymer and thus a demixing. In some cases, closed miscibility loops can be observed. 

Another kind of chiral amino alcohol (170), derived from L-proline, has been synthesized and applied to the enantioselective MBH reaetion of various aromatic aldehydes with MVK, affording the eorresponding adducts in high yields with modest selectivities in poly(ethylene glycol) (PEG) 400 (Scheme 2.83). Notably, this catalytic system could be easily recovered and reused in three runs without significant changes in yields and selectivities. ... 

S8 39 POLY AND l AND PROLINE Title Synthesis of crosslinked poIy(vinyI alcohol) with proline 18621 6 S8 1 615 NYLON06... 

Phenyl-1,2,4-triazin-3-yl)-2,2 -bipyridine, P-00206 2-(5-Phenyl-1,2,4-triazin-3-yl)-1,10-phenanthroline, P-00207 Phosphoramidothioic acid 0,0-bis(l-methylethyl)ester, P-00215 Picriminazosulfoxine, P-00234 >Poly(vinyl alcohol), P-00249 4,4, 4",4" -(21 //,23//-Porphine-5,10,15,20-tetrayl)tetrakis[ 1 -methylpyridiniumj Tetrakis(/7-toluenesulfonate), in P-00252 Proline (R)-form, in P-00257... 

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