Polymer, Vol.35, No.11, 2443-2446, 1994
Improved Method for the Preparation of Poly(N5-(2-Hydroxyethyl)-L-Glutamine) by Aminolysis of Poly-Gamma-Benzyl-L-Glutamate)
This paper describes the synthesis of poly[N5-(2-hydroxyethyl)-L-glutamine] (PHEG) by the aminolysis of poly(gamma-benzyl-L-glutamate) (PBG) with 2-aminoethanol. The effects of the temperature and addition of the bifunctional catalyst, 2-hydroxypyridine (2-HP), on the kinetics of aminolysis were studied. The results suggest that the aminolysis reaction takes place much faster with increasing temperature and an increasing amount of added catalyst. Moreover, chain scission, due to aminolysis of the amide bonds of the polymer backbone, can be minimized by the addition of the appropriate amount of 2-hydroxypyridine. These data demonstrate the feasibility of the described method to prepare PHEG derivatives with well controlled molecular weights.