You Do Need power plug adapter while traveling from Argentina to Uruguay.

Here is Why You Need An Adapter

The outlet and plug type used in Uruguay are C, F and L and in Argentina are C and I. This is how they look like.

Argentina

In Argentina, outlets of type C and I are in use.

Type C

Type I

Uruguay

In Uruguay, outlets of type C, F and L are in use.

Type C

Type F

Type L