Fiber Polymer Composite

An extruded thermoplastic composite material comprising:

• (i) about 10 to 80 wt. % of a polymer phase comprising a thermoplastic polymer with a density of less than about 1.9 g-m−2:
• and
• (ii) about 20 to 90 wt. %. % of a dispersed particulate phase consisting essentially of greater than 50 vol. % of a reinforcing cellulosic fiber and the balance comprising at least 5 vol. % of a mineral particulate or a glass particulate, the dispersed phase comprising about 0.2-6 wt. % of a coating of at least one interfacial modifier to form a mixture;
• and
• wherein the composite material has a Young's modulus of greater than 700 Mpa and the interfacial modifier provides a coating on the dispersed particulate that can form a close association between the particulate and polymer and covalent bonding between fiber, particulate and polymer are not formed.

An extruded thermoplastic composite structural member comprising:

• (i) about 10 to 80 wt. % of a polymer phase comprising a thermoplastic polymer with a density of less than 1.9 g-m−2:
• and
• (ii) about 20 to 90 wt. % of a dispersed particulate phase consisting essentially of greater than 50 vol. % of a reinforcing cellulosic fiber and the balance comprising at least 5 vol. % of a mineral particulate or a glass particulate, the dispersed phase comprising about 0.2-6.00 wt. % of a coating of at least one interfacial modifier to form a mixture;
• and wherein the composite material has a Young's modulus of greater than 700 MPa;
• and the interfacial modifier provides a coating on the dispersed particulate that can form a close association between the particulate and polymer and covalent bonding between fiber, particulate and polymer are not formed.