Is it legal to have a collection of interesting articles printed for personal use, in the form of a book?
I don't see how printing a paper for one's personal use could be legal, but printing 2 or 10 and binding them together would be illegal. As long as it is actually strictly for your personal use, if printing a paper for your personal use is legal where you live, then certainly binding them together is.

But I would advise against actually binding them. Let's say you do, then the next day you find a new paper on the same topic. You will want to kick yourself, because you will not be able to add it to the collection. I think that most people have bunches of physical folders, with papers consisting of stapled (or otherwise kept together) stacks of papers, but separate papers not being bound to one another.