C. Jaimes et al., POLYMERIZATION OF (R,S)-BETA-BUTYROLACTONE FROM TETRAISOBUTYLDIALUMINOXANE (TIBAO) CATALYST, European Polymer Journal, 32(10), 1996, pp. 1175-1181
Poly-beta-hydroxybutyrate (PHB) was prepared by ring-opening polymeriz
ation reactions of racemic beta-butyrolactone ((R,S)-beta-BL) using te
traisobutyldialuminoxane (TIBAO). A study was conducted on the effects
of catalyst concentration, polymerization time, polymerization temper
ature, nature of solvent, modifications of the catalyst by water addit
ion and TIBAO purification on the yield and molecular weights of the p
olymer obtained. Optimal conditions for the synthesis of highest yield
and molecular weights of the polymer were determined. By adding water
to TIBAO, molecular weights increased but also polydispersities. Quan
titative yields of crude PHB were obtained but reaction times required
were long, molecular weights were quite low and molecular weight dist
ributions were broad. A study of the TIBAO stereospecificity, the poly
mers structure and morphology and their biodegradation will be conside
red in future papers. Copyright (C) 1996 Elsevier Science Ltd