TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The multifunctional monomer is a multifunctional, ethylenically unsaturated monomer comprising a metathesis-reactive monomer and is reacted with second block of the block copolymer in the presence of a metathesis catalyst. The metathesis-reactive monomer comprises a cyclic olefin consisting of dicyclopentadiene and/or cyclooctene. The metathesis catalyst comprises a functional group-tolerant metathesis catalyst comprising second generation Grubb's catalyst.    TECHNOLOGY FOCUS - POLYMERS - Preferred Method: The preparation of polymer composite involves treating the composite with a chemical etchant to remove the first block of the block copolymer in the second continuous phase to form pores having average pore diameter of 1-500, preferably 10-50 nm; and reacting the multifunctional monomer and the block copolymer in the presence of a homopolymer polylactide. Preferred Components: The first block is polylactide block and/or sulfonated polystyrene block. The second block of the block copolymer comprises a norbornenyl group including copolymer of styrene and norbornenylethylstyrene. The block copolymer further comprises a third block. The block copolymer is polylactide-poly(styrene-co-norbornenylethylstyrene) block copolymer, sulfonated polystyrene-poly(styrene-co-norbornenylethylstyrene) block copolymer and/or polylactide-poly(dimethylacrylamide)-poly(styrene-co-norbornenylethylstyrene) block copolymer. EXAMPLE - Poly(norbornylstyrene-s-styrene)-b-polylactide block copolymer, dicyclopentadiene and tetrahydrofuran (THF) were premixed in a glass vial with stirring and second generation Grubbs catalyst dissolved in THF was added. Subsequently, thin films were cast on a silica substrate, and then crosslinked at room temperature for 6 hours with slow THF evaporation, followed by annealing at 100 degrees C for 1 hour in air. Degradation of a sample of the resultant film was performed in 0.5 M sodium hydroxide solution and methanol (MeOH) at vol. ratio of 40:60, and water at 70 degrees C for 3 days, and then rinsed with MeOH. Finally, films were dried under vacuum at 50 degrees C. The film exhibited bicontinuous structure; ultimate elongation of 11%; and tensile strength of 32 MPa.