I'm trying to work out how much energy from sunlight will be absorbed (converted to heat energy) by a silicone polymer. I need the mass attenuation coefficient (from what I can tell at least) so that I can work out the amount of heat energy the water inside a black silicone polymer container would absorb if the container were left in sunlight. I'm still not quite sure how to fully figure this out though (I'd surely need to take into account the heat capacity of the silicone polymer, as well as the surrounding air, because not all of the heat given out by the container would be absorbed by the water). If anyone could help with this it would be much appreciated. Any relevant formulae and variables to take into account would be great. Thanks.