import arcpy
# Determine range of FIDs (Shapefile) or ObjectIDs (GDB feature class)
polyg = "PATH_TO_FEATURECLASSS"
polygIDS = [x for x in arcpy.da.SearchCursor(polyg, ["OBJECTID"]]
# Loop through rows, creating layer each time
for i in polygIDs:
    whereclause = """{} = {}""".format(arcpy.AddFieldDelimiters (datasource, field), i)
    arcpy.MakeFeatureLayer_management(polyg,"polyg_lyr{}".format(i), whereclause)
    # Setup Output name / destination
    outKML = "PATHTOKML{}".format(i) #unique name by ObjectID
    # Output KML / KMZ file
    arcpy.LayerToKML_conversion("polyg_lyr{}".format(i), outKML)
    # Delete layer to free memory
    arcpy.Delete_management("polyg_lyr{}".format(i))