Provided according to the invention are cross-linked polymers comprising an anhydride or partially hydrolyzed anhydride functionalized polymer having oligomeric polyimide cross-links, providing a polymeric composite on a molecular scale, and shaped articles made therefrom. In some embodiments the shaped articles are particularly well suited for electronics applications. The shaped articles are characterized by low CTE (coefficient of thermal expansion), low dielectric constant (Dk), low dissipation factor (Df), high strength, high modulus and high toughness.