Characterization of thermotropic liquid crystalline polyester/polysulfone blends

Abstract

The morphology, rheology, and mechanical properties of blends of polysulfone (PSF) with up to 65% of a wholly aromatic liquid crystalline polymer (LCP) were investigated. In injection molded specimens a skin-core morphology was observed with the LCP minor phase oriented in the skin and globular in the core. Scanning electron microscopy of fractured surfaces showed sharp phase boundaries, suggesting low interfacial adhesion. The neat PSF and blends with low amounts of LCP exhibited a low shear Newtonian plateau not observed in the blends with high LCP levels. The addition of LCP to PSF resulted in an increase in stiffness, a small increase in tensile strength, and a significant improvement in processability.

Reinforced poly(ether sulfone) materials by blending with a semiaromatic liquid crystalline copolyester

“…The higher fibrillation of the skin is a consequence of its higher shear flow. Other injected blends, such as PSF/VA 4 or PES/ VA 14 showed similar morphologies. In other injected PES-based blends, 13,22 there were some morphological differences, especially in the core.…”

“…In the center of the core, probably because of viscosity effects, the LCP domains were interconnected, revealing the proximity of phase inversion. The core of both PSF/VA 4 and PES/VA 14 blends at high LCP contents showed large irregular domains and big particles. In other injected PES/LCP blends, 13,22 however, some thin fibrils with aspect ratios that decreased with increasing LCP content were present in the core.…”

“…These blends were processed mostly by extrusion, 6 -9 and one by injection. 4 When the phase behavior or processability was studied, the blends were immiscible 4,6 -8 and the LCP reduced the viscosity of the blends. 4 -6,10 The injected PSF/VA blends 4 showed a fibrillar and well-developed layered LCP structure in the skin and a globular structure in the core.…”

“…4 When the phase behavior or processability was studied, the blends were immiscible 4,6 -8 and the LCP reduced the viscosity of the blends. 4 -6,10 The injected PSF/VA blends 4 showed a fibrillar and well-developed layered LCP structure in the skin and a globular structure in the core. The stiffness was proportional to the composition, but only small increases in the tensile strength were observed.…”

Misturas de poliestireno e poliéster líquido-cristalino.

“…Existe na literatura estudos sobre misturas de LCP com poliestireno (PS) [1][2][3]5,[30][31][32], polietileno (PE) [6,8], polipropileno (PP) [33][34][35][36], elastômero termoplástico poli(éter-ester) (TPEE) [37], poliamidas (PA) [9,[39][40][41][42], policarbonatos (PC) [10,[43][44][45][46], polieterimida (PEI) [41,47], polissulfona (PSU) [48][49][50], poli(tereftalato de etileno) (PET) e poli(tereftalato de butileno) (PBT) [51][52][53][54], polímero fluorado [55], poli(éter-éter-cetona) (PEEK) [50,56,57], poliimida (PI) [58] e copolímero de estireno e vinil fenol (PVPh) [59], e muitas pesquisas sobre materiais poliméricos estão focadas nesse assunto.…”