In order to study the influences of epitaxial crystallization on the space charge injection and transport process in low-density polyethylene（LDPE）

we adopted glass（G）

polytetrafluoroethylene（PTFE）

and isotactic polypropylene（i PP） as the substrates to prepare LDPE samples

denoted as LDPE-G

LDPE-PTFE

and LDPE-i PP

respectively

for the test of space charge and DC breakdown at room temperature. The results show that positive packet-like space charge injects at anode and moves towards cathode at the field of-100 MV/m. The space charge in samples will result in the distortion of electric field with the maximum value of 177 MV/m during the polarization. As for LDPE-G

LDPE-PTFE and LDPE-i PP

the amount of the negative charge injects from the small to the large

and the positive charge injects from the large to the small. The Weibull breakdown strength will arrange as follows: LDPE-i PP>LDPE-PTFE>LDPE-G. It is analyzed that the epitaxial crystallization changes the surface relative permittivity of LDPE through the different lamella arrangement

affecting the charge injection barrier height of both positive and negative charges. In addition

the injection difficulty of positive space charge and the arrangement of lamella on the LDPE surface alters the probability of breakdown channels.