Not really. But it is so easy do so during the creation or after.
- Typing C (_Close) when drawing
- Selecting them and going to the properties palette, it is easy to change their status, one of the last parameter in the palette, that you can change when you want. In a multiple selection, just apply the drop-down menu to select only polylines, if ever...
- Last but not least, you can PEDIT, choose the Multiple and edit several at the same time by closing them, pleased to the option. Your selection will filter up the polylines inside any mix of objects. Practical.