Poly(phenylene sulfide) (PPS)/Vectra A blends were directly injection molded and obtained throughout the composition range both as molded, low crystallinity, and annealed highly crystalline materials. The blends were immiscible, but, contrary to an earlier work on PPS/Vectra A blends, they showed a clear fibrous morphology that was a consequence of the higher viscosity of the matrix compared with that of the Vectra A at the shear strain rate used. The mechanical properties of the annealed blends showed that when highly crystalline materials are sought, annealing post‐cold molding is a valid alternative to molding at high mold temperatures. The fracture properties of the as‐molded blends, such as ductility and tensile strength, were higher than in annealed blends, as a consequence of the higher deformability of the less crystalline structure. The presence of the LCP in the as‐molded low‐crystallinity PPS blends counteracts their intrinsic lower stiffness by means of a faster stiffness increase when Vectra A was added, compared with that which took place in annealed blends. These facts rendered the as‐molded PPS/Vectra A blends alternative materials to the usual highly crystalline ones.
Polycarbonate (PC)/Ultrax blends were obtained by injection molding changing both the Ultrax content and the injection temperature, speed and pressure. The change of injection speed or pressure did not lead to significant change of morphology or properties. An injection temperature of 300°C allowed some reaction to take place between the components and the presence of some reacted Ultrax in the PC‐rich phase, but the mainly spherical morphology obtained lead to poor mechanical properties. At a lower injection temperature of 280°C, however, reactions were almost not detected, but fibrillar structures were produced, mainly because of the higher matrix viscosity. This gave rise to important increases not only in modulus and tensile strength but also in flexure properties and creep dimensional stability.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.