The effect of nucleating agent (zinc phenylphosphonate

PPZn) and its adjuvant (E61) on the crystallization morphology and capacity of poly(lactic acid) (PLA) was investigated.The crystallization morphologies of PLA are varied with the content of PPZn and E61.PPZn can effectively act as nucleus sites of PLA when the content of PPZn is 0.1 wt%

and spherical crystal of PLA is obtained.However

needle-like crystal is observed with an increase of PPZn (0.3 wt%) owing to the self-assembly of PPZn.The effect of E61 on the crystallization morphologies of PLA is further investigated when the content of PPZn is fixed at 0.3 wt%.The needle-like crystal of PLA without E61 changes to spherical crystal with low content of E61 (0.06 wt%)

which may be attributed to the improvement of crystal growth mainly on the short axis but not on the long axis of PPZn.While a higher content of E61 ( 0.15 wt%) can inhibit the crystal growth of PLA

resulting in the formation of needle-like structure.In addition

the inhibition of E61 with 0.3 wt% shows more serious than that with 0.15 wt% E61.The results of DSC and rheological test demonstrate that the crystallization rate can be obviously improved by the introduction of PPZn

while the addition of E61 has little effect on that of PLA.