Quaternion Rotations and Rigid String Theory Resemblance.

Quaternion 90 degree rotations could be connected to sub quantum structures of some rigid string theory.
See: 4D Quaternion 90 degree rotation resemblance with Rigid String Mutation by internal 90 Degree Rotations.
See rigid Higgs Ring rotation over three hinges, with interlocked merger Quarks (according to Quantum FFF Theory)
see also: https://www.academia.edu/6610669/3_Dimensional_String_Based_Alternative_Particles_Model