The non isothermal crystallization behaviours of poly(L lactic acid)(PLLA) and its composites with hydroxyapatite(HA)

chitin(CHI)

and chitosan(CHS) respectively were investigated by differential scanning calorimetry(DSC) The kinetic parameters of non isothermal crystallization were derived based upon Mandelkern’s and Ziabicki’s methods Results show that with increasing cooling rate

the crystallinities of PLLA and PLLA in the composites decrease rapidly and the Avrami exponent n get smaller The components in the composites are of increasing the n of PLLA and thus favourable to the PLLA crystal organizations growing in 3 dimension The non isothermal crystallization rate constant Zc obtained according to Mandelkern’s method and the parameter of kinetic crystallizability G derived from Ziabicki’s theory increase with the increase of cooling rate while the specific kinetic crystallizability Gc is independent of cooling rate; However

Gc is affected by the components in the composites

in which HA makes the Gc smaller while CHI and CHS increase the Gc.