Isothermal and non-isothermal crystallization kinetics of three metallocene-catalysed short-chain-branched polyethylene (SCBPE) fractions with different degree of branching were investigated by using differential scanning calorimetry (DSC).Narrow molecular weight fractions (Mw=20

000 and Mw/Mn3 per 1000C) are 1.6

10.4

40 respectively.The regime Ⅰ-Ⅱ transition temperature are 119.8℃

115.9℃

113.3℃ with the decreasing of degree of branching.Increasing the branch content decreases the rate of secondary nucleation

i

relative to the rate of surface spreading and so increases the range of supercooling over which regime I exists.The rate of bulk crystallization for both isothermal and non-isothermal crystallization decreases with the increasing of degree of branching.Both Ozawa Equation and Kissinger Equation are invalid for non-isothermal crystallization kinetics of SCBPE fractions

tha means the effects of the branched chain on crystallization process are more complex than expected.