Q. Can I request my textbook(s) through Interlibrary Loan?
You CAN, but obtaining textbooks via Interlibrary Loan (ILL) is not always your best option. If it's a required textbook here at Purdue, it likely is also at another university. Textbooks are not usually purchased by libraries due to the fact that the editions change constantly and they become obsolete quickly. If other libraries do own the textbook you need, they are most likely checked out by their own students or on course reserve at their libraries.
If you need a textbook urgently, ILL may not be your best option.