The results (Table 2) show that as already expected, increased population of N-H
hydrogen bonded groups and degree of phase separation is obtained for Type A
samples. Moreover, DSC thermographs (Figure 2) manifest that Type A samples
begin with low glass transition temperature at -32؛C caused by soft phase ( Figure 2a
,TypeA) followed by a small crystallization exotherm and larger melting endotherm
(Figure 2b,Type A) which are due to crystallization and destructive melting of HTPB
soft phase during DSC. There is also a clear glass transition related to hard phase at
72؛C (Figure 2a, Type A). On the other hand type B samples start with a low glass