It is more specifically called the floss silk tree, but it is a kind of kapok. Chorisia speciosa has been re-genus-ed as Ceiba speciosa, and is from the southern hemisphere American tropics. The name kapok is more specifically used for Ceiba pentandra, which is from the northern hemisphere American tropics.
I saw some truly astonishing examples of C. speciosa in northern Argentina, where it is native. Absolutely massive, trunk about 6 feet in diameter, the flowers of a single tree perfuming a whole square. In Spanish, they call it "palo borracho", which means drunken stick, referring to the way the trunk bulges out as if it has a pot-belly on mature specimens, which becomes more obvious on mature trees. The "thorns" on the trunks can be something to behold too.