Abstract: A male connector comprises: a holder, attached rotatably to the outer peripheral surface of a plug main unit portion, having male threads formed on the outer peripheral surface thereof and having sliding grooves formed at specific intervals at the rearward side on the outer peripheral surface; and a knob portion, formed integrally with engaging protruding portions that have engaging hooks on the tip end sides thereof and that sliding in the sliding grooves, where the knob portion is attached so as to be able to rotate together with the holder.

Abstract: Telechelic polymers having two reactive functional groups at the same polymer chain end are disclosed. These polymers can be prepared by combining a cycloborane initiator, at least one free radical polymerizable monomer and oxygen to form a polymer segment having a borane residue at one end of the polymer segment resulting from the cycloborane initiator; and converting the borane residue to at least two functional groups to form the telechelic polymer.