You Do Need power plug adapter while traveling from Equatorial Guinea to Puerto Rico.

Here is Why You Need An Adapter

The outlet and plug type used in Puerto Rico are A and B and in Equatorial Guinea are C and E. This is how they look like.

Equatorial Guinea

In Equatorial Guinea, outlets of type C and E are in use.

Type C

Type E

Puerto Rico

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

Type A

Type B