| Study on the Toughning Mechanism of the Dynamic Vulcanized PPöEPDM Blends by the Dynamic Mechan ical Analysis |
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Writer: Wei Wu, Dafei Zhou Publication: Journal of East China University of Science and Technology, 1999, 25(4):377-381 Abstract: The differences and the characterist ics of the dynamic mechanical resonances between dynamic vulcanized and unvulcanized PP/PDM blends with different content of EPDM were studied by means of the dynamic mechanical analysis. The results showed that, compared with the unvulcanized PP/EPDM blend, the dynamic vulcanized PP/EPDM has the characteristics of smaller(Tg )larger mechanical loss peak width, higher mechanical loss strength and lower mechanical loss peak temprature at the room and low temp ratu re, a change in the peak value of the mechanical loss at 60～70℃ and some appearances of β and γ secondary transit -ion under the α-transition (Tg) of EPDM etc. The main reason why the toughning effect of the dynamic vulcanized PP/E PDM b lend w as bet ter than the unvalcan ized PP/EPDM b lend is that, the dynamic vulcanized PP/ PDM can increase the com- patibility between the two phases PP and EPDM, increase the mobility of the molecular segments and form the new chemical structures which can have the mobility at the low temprature etc. From the results it can be also predicted that the dynamical vulcanized PP/EPDM blendsmay have the advantages of the high cold properties and high holding ratio of the modulus at the high temprature.
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