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Structure of Urethane Copolymers of 3,3‐Bis(azidomethyl)oxetane and 3‐Azidomethyl‐3‐methyloxetane
Authors:Vladimir A Petrov  Nina V Kuznetsova  Timur I Muhametshin  Aydar T Gubaydullin
Abstract:Polyurethane copolymers of 3,3‐bis (azidomethyl) oxetane (BAMO) and 3‐azidomethyl‐3‐methyloxetane (AMMO) with molecular structures of types B(AB)n, A(AB)n, (BB)n and ABn with different ratios of oligomeric units were investigated, where A is the non‐crystallizable “soft” block of oligoAMMO and B is the “hard” block of oligoBAMO and the included urethane diol fragments. The amorphous‐crystalline structures of copolymers BAMO and AMMO were elucidated by wide angle X‐ray diffraction measurements. The influences of the molecular structure and the ratio of oligomeric units on the structural parameters were identified. The degree of crystallinity is in a range from 8 to 22 % and sizes of the crystallites were determined. The defectivenesses of first and second kind in the structure were evaluated, which show high values of the first kind defectiveness (approx. 20 %), which describes the displacement of theoretical lattice sites and the existence of unequal sizes of the lattice sites, and minor values for the second kind defectiveness (approx. 3 %), which describes the lattice site disorder in large distances. Small‐angle X‐ray diffraction measurements were used to investigate the domain structures of copolymers BAMO and AMMO. The distribution and sizes of the crystallites in the structures of the copolymers were calculated.
Keywords:3  3‐Bis(azidomethyl)oxetane  3‐Azidomethyl‐3‐methyloxetane  X‐ray diffraction  Structure elucidation  Copolymers  Crystallinity
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