before hydrogenation will be less than or equal to 15 000 more preferably less than or equal to 13 000 and most preferably less than or equal to 12 000 it is important to note that each individual block of the hydrogenated block copolymer of the present invention can have its own distinct molecular weight in other words for example two vinyl aromatic polymer blocks may each have a different molecular weight mp and mw as used to throughout the specification are determined using gel permeation chromatography gpc the molecular weight of the substantially hydrogenated block polymer and properties obtained are dependent upon the molecular weight of each of the monomer unit blocks for substantially hydrogenated block polymers molecular weights are determined by comparison to narrow polydispersity homopolymer standards corresponding to the different monomer unit segments for example polystyrene and polybutadiene standards are used for sbs block copolymers with adjustments based on the composition of the block copolymer also for example for a triblock copolymer composed of styrene s and butadiene b the copolymer molecular weight can be obtained by the following equation where mc is the molecular weight of the copolymer x is the weight fraction of s in the copolymer ma is the apparent molecular based on the calibration for s homopolymer and.