Nonisothermal crystallization of poly(phenylene sulfide) in presence of molten state of crystalline polyamide 6

The nonisothermal crystallization and melting behavior of a poly(phenylene sulfide) (PPS) blend with polyamide 6 (PA6) were investigated by differenti al scanning calorimetry. The results indicate that the crystallization para meters for PPS become modified to a greater extent than those for PA6 in th e blends. The PPS and PA6 crystallize at high temperature as a result of bl ending. The crystallization temperatures of PPS in its blends are always hi gher than that of pure PPS and are independent of the melting temperature a nd the residence time at that temperature. The PPS crystallization peak bec omes narrower and the crystallization temperature shifts to a higher temper ature, suggesting a faster rate of crystallization as a result of blending with PA6. This enhancement in the nucleation of PPS could be attributed to the possible presence of interfacial interactions between the component pol ymers to induce heterogeneous nucleation. On the other hand, the increase i n the crystallization temperature of PA6 can be attributed to the heterogen eous nucleation provided by the already crystallized PPS. The heterogeneous nucleation induced by interfacial interactions depends on the temperature at which the polymers remain in the molten state and on the storage time at this temperature. (C) 1999 John Wiley & Sons, Inc.