To resolve the crack,cracking,fall off and other problems of the epoxy coating,the epoxidized HTPB which
named EHTPB,was added to the RT-III to improve the elongation of coating. The toughening coating RT-IV not only had a
good elongation and manufacturability,but also had a good insulation property compared with the RT-III. However,the in鄄
terfacial property would reduce appropriately. The RT-IV has been verified by the flight experiment. By studying on increas鄄
ing the elongation of RT-III,it is found that the elongation will be increasing when the EHTPB is added to the coating.