Biopolyesters in Tissue Engineering Applications - Advances in Polymer Science - page 9

Fig. 4 a Mechanical properties of solution-cast P3HB films plasticized with 30%each
of triethyl citrate (TEC), butyryltrihexyl citrate (BTHC), glycerin tributyrate (GTB), and
dibutyl sebacate (DBS) [71, 72]. b Mechanical properties of solution-cast P3HB films
blended with 30% each of degraded P3HB (dg-P3HB, M w = 3000), at-P3HB, st-P3HB, and
P4HB [38, 72]
( M w 11 million) have comparable mechanical properties with those of com-
mon high molecular weight P3HB ( M w 500 000 to 1 million). Low molecular
weight P3HB shows increasing brittleness with decreasing molecular weight,
and mechanically stable films cannot be prepared below a molecular weight
of 50 000. Films can still be prepared from mixtures of high and low molecu-
lar weight P3HB showing mechanical properties comparable with those of
unmodified high molecular weight P3HB (Fig. 4b) [38].