Intramolecular phase transitions in polymer chains with rigid branches

The steric globular structure forming inside a short and thin chain with rigid branches is attributed to the parallel packing of the latter. Depending on the ratio of the branch length to that of the chain segment present between branches one can find either a parallel structure due to the free branch ends all pointing to the same side, or a non-parallel one. The transitions between these two structures, and also those of both these structures to that of a coil, have been investigated. All these are first order phase transitions.