'Man-made' is an adjective, see http://www.ldoceonline.com/dictionary/man-made
'Man-made materials' should be a noun phrase instead of a sentence.
Not a teacher.
Student or Learner
The questions are:"man-made material"
1. Is "man" object or possesive pronoun? (Subject doesn't make sense)
2. Does whole sentence mean "Material that has been made by either a man/person or people"?
I am not a teacher.
1. Man-made is an adjective. 'Man' can't be separated from it.
2. It means that it's not naturally occurring.