Composites comprising nonwoven structures and foam

A composite, comprising:

• a nonwoven structure comprising first fibers comprising polyacrylonitrile and second fibers comprising polyetherimide;
• and
• a foam comprising melamine and/or polyvinylidene fluoride and/or polyimide and/or polyetherimide, the foam having open pores having an average cell size of less than about 1 mm, the foam immobilized to the nonwoven structure,
• wherein the composite is constructed and arranged to satisfy the flammability test defined in 14 C.F.R. §25(App. F)(VI) (2012).

A composite, comprising:

• a nonwoven structure comprising first fibers comprising polyacrylonitrile and second fibers comprising polyetherimide;
• and
• a foam comprising melamine and/or polyvinylidene fluoride and/or polyimide and/or polyetherimide, the foam having open pores having an average cell size of less than about 1 mm, the foam immobilized to the nonwoven structure,
• wherein the composite is constructed and arranged to absorb at least about 70% of sound having a frequency of 500 Hz that is directed at the composite.

A composite, comprising:

• a nonwoven structure comprising first fibers and second fibers, the second fibers having a composition different from the first fibers;
• and
• a foam comprising melamine and/or polyvinylidene fluoride and/or polyimide and/or polyetherimide, the foam having open pores having an average cell size of less than about 1 mm, the foam immobilized to the nonwoven structure,
• wherein the composite is constructed and arranged such that, when substantially the entire outer surface of the composite is exposed to a radiant heat flux of 1.7 W/cm2 and an open pilot flame, the composite exhibits no flame propagation beyond 2 inches and no flame time beyond 3 seconds after exposure to the open pilot flame for 30 seconds.

A composite, comprising:

• a nonwoven structure comprising first fibers comprising polyacrylonitrile and second fibers comprising polyetherimide;
• and
• a foam comprising melamine and/or polyvinylidene fluoride and/or polyimide and/or polyetherimide, the foam immobilized to the nonwoven structure,
• wherein the composite is constructed and arranged to satisfy the flame penetration resistance test defined in 14 C.F.R. §25(App. F)(III) (2012).