A new series of diblock polystyrenebpoly(Dlactide) (PSbPDLA) were successfully synthesized with narrow molecular weight distribution and a PDLA block weight fraction fw of 0～0.61. By means of temperaturemodulated differential scanning calorimeter (TMDSC)

DSC and polarized optical microscopy

thermal and crystallization kinetics of these diblock copolymers have been studied along with the semi-crystalline PDLA homopolymer.It was found that the increase in rigid amorphous polystyrene block led to remarked confinement effect on melting point

degree of crystallinity and crystallization kinetics for the semi-crystalline PDLA blocks.The cold crystallization temperature and crystal equilibrium melting temperature for the PDLA block chains were revealed to be 14℃ and 38℃ lower than those of PDLA homopolymers

respectively.It was also noted that the crystallization behavior and apparent crystal growth rate were observed to vary at a temperature near the glass transition temperature of PS block chains.In addition

POM results indicated the diblock PS-b-PDLA organized spherulites

and apparent crystal growth rates not only depended on isothermal crystallization temperature

but the PDLA blocks weight fraction.Taking the effect of crystallization of PDLA blocks into consideration

these evidences may be helpful for controlled fabrication of 3D mesoscopic structures by self-assembling diblock PS-b-PDLA.