Moreover, the formation of hydrogen bonds between the APP powders and TPU molecular chains improve the compatibility, which decreases the migration of the MTAPP .
4 and Table 3 that the initial decomposition temperature (defined as [T.sub.5wt%]) of PP/MTAPP composites is lower than that of pure PP due to the low thermal stability of MTAPP. Compared with PP/MTAPP composites, it is clearly found from Table 3 that the degradation temperatures of 5, 10, and 20 wt% mass loss ([T.sub.5wt%], [T.sub.10w%], and [T.sub.20wt%]) of PP/MTAPP/PA6 composites decrease due to the addition of PA6, and gradually decrease with increasing the content of PA6, which is possibly attributed to be the esterification between acid source and carbonization agent.
For the samples of PPMA1-3, with increasing the content of PA6 and decreasing the content of MTAPP, the crystallinity of PP in the composites decreases sharply.
As listed in Table 5, the incorporation of MTAPP deteriorates seriously the tensile strength, impact strength and elongation at break of the PP matrix.