The Crystallization Properties Of PTT Alloy Controled By MMT

In the process of PTT alloying, there are crystallization performance degradation with PTT. We put MMT into PTT/PP, PTT/PC, PTT/ABS alloy in order to research the multilevel structure of nanometer MMT on the crystallization performance of PTT alloy and control them.The result of nanometer MMT working on crystallization of PTT/PP alloy showed that,2wt% MMT mainly distributed along the interface of PTT/PP alloy and the PTT phase as the form of a strip-type aggregation. The peak crystallization temperature of PTT phase turned from 174.3℃ to 193.4℃ in PTT/PP (80/20) alloy. The temperature between initial crystallization temperature and peak crystallization temperature decreased 10.0℃. However peak crystallization temperature of PP phase didn’t move obviously. With the increase of dosage of MMT, it had significantly influenced the dispersion and aggregation of dispersed phase staying in matrix, however crystallization performance didn’t change obviously. The stripping degree of MMT was increased when the dosage of interface compatibilizer PP-g-MAH was 5wt%. The interface compatibilizer improved the interface state of PTT alloy, at the same time it affected the crystallization of PTT phase.In this paper, we took 70/30 PTT/PC/1wt%MMT nanocomposite for example to study some factors such mixing temperature, mixing order and rotate speed how to work on the crystallization property of PTT/PC alloy. The results were that, when in low mixing temperature and the method of master batch, MMT mainly distributed along the interface of PTT/PP alloy and the PTT phase as the form of partly stripping and partly intercalation. It formed spherical MMT layers along the interface orientation distribution. The spherical MMT layers had strong ability to induce crystallization of PTT phase. It made up the inhibiting effect of PC segment in the interface on PTT spherulite growth with the improvement of peak crystallization temperature of PTT phase. With the increase of dosage of MMT and limited interface area, more and more MMT particle dispersed in phase interface and PTT phase. The addition of MMT promoted the nucleating ability of PTT phase, at the same time it obstructed process of growth. When rotate speed was too low to make MMT disperse in matrix, the interface compatibilizer epoxy can increase stripping degree of MMT in matrix. But when rotate speed was high enough to make MMT disperse in matrix, epoxy reduced peak crystallization temperature and crystalline enthalpy of PTT alloy on the contrary. Because inhibiting effect of interface compatibilizer exceeded its acceleration of crystallization.The result of nanometer MMT working on crystallization of PTT/ABS alloy showed that, when the dosage of MMT was 1 wt%, peak crystallization temperature of PTT phase moved to high temperature (10.3℃) in PTT/ABS alloy. The temperature between initial crystallization temperature and peak crystallization temperature decreased 6.6℃. But crystalline enthalpy decreased 7.8J/g. MMT in the nanocomposite promoted the crystallization of PTT phase deeply, but it also disturbed orderly arrangement in the crystallization process of PTT segment and its the perfect degree of the crystallization. The peak crystallization temperature moved lower for 3.3℃ with the addition of 1wt% epoxy. Because inhibiting effect of capacity expansion process surpassed acceleration of MMT.