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

Here is Why You Need An Adapter

The outlet and plug type used in Papua New Guinea is I 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

Papua New Guinea

In Papua New Guinea, outlets of type I are in use.

Type I