pure PBT and TPU/PBT blends (TPU content no more than 15 wt%) exhibit two melting peaks, and the peak of pure PBT at higher temperatures is dominant compared with that at lower temperatures.
The origin of these peaks has been ascribed to the presence of different morphology and simultaneous melting and reorganization of the crystallites. With the increase of TPU content, the melting point of all blends is reduced.This is because a growing number of branched or crosslinking structure appeared in the blends with the increase of TPU content. Moreover,the peak intensity of the curve showed a trend of decline with increasing TPU content, especially when the content was from 20 to 30 wt%. On the one hand, this is because an increase in the amount of TPU enhances the blend interface reaction, giving better compatibility between TPU and PBT. On the other hand, due to it's flexibility, the TPU disrupted the regularity of PBT resin, so that the crystallinity of the blends was reduced, resulting in a decrease of the peak intenslty