You Do Need power plug adapter while traveling from Puerto Rico to Balearic Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Balearic Islands are C and F and in Puerto Rico are A and B. This is how they look like.

Puerto Rico

In Puerto Rico, outlets of type A and B are in use.

Type A

Type B

Balearic Islands

In Balearic Islands, outlets of type C and F are in use.

Type C

Type F