biological oils , conjugated biological oils , and metathesized or cometathesized biological oils are polymerized or co - polymerized faith divinylbenzene , norboradiene and dicyclopentadiene using a bf 3 . oet 2 initiator to provide plastics from renewable resources . the products are thermosetting polymers having highly crosslinked structures , room temperature modulus of about 10 9 pa , and excellent thermal stability , making the products useful for applications where current biodegradable plastics are not useable .