I have asked myself (not tested) if it is possible to integrate both bootstrap and materializecss into the same project
Since both frameworks are for the same purpos
I'm not sure that's possible. Material Design is something new from Google, and includes responsive as part of it, while the Bootstrap library is from Twitter and seems to be mostly responsive-oriented.
Check out this conversation : http://forums.oscommerce.com/topic/407994-material-design/?hl=material
I suspect that they are not going to be integrated with each other, and will conflict badly, but maybe someone else has more information.