We report load transfer and mechanical properties of chemically derived single layer graphene (SLG) as reinforcements in poly (dimethyl) siloxane (PDMS) composites. Shear mixing reduced graphene sheets in polymers resulted in a marked decrease of the 2D band intensity due to doping and functionalization. Raman G mode shifts of 11.2 cm(-1)/% strain in compression and 4.2 cm(-1)/% strain in tension are reported. Increases in elastic modulus of PDMS by ~42%, toughness by ~39%, damping capability by ~673%, and strain energy density of ~43% by the addition of 1 wt% SLG in PDMS are reported.