Additive Effects on Thermotropic Liquid Crystal Polymer Alloys II. Effects of Third Component of Thermotropic Liquid Crystal Polymer on Mechanical Properties of Vectra A-Reinforced Poly(butylene terephthalate)

Abstract

ABSTRACT:The effects of addition of the 3rd component of thermotropic liquid crystal polymer (TLCP) on the mechanical properties and structure of Vectra A-reinforced poly(butylene terephthalate) (PBT) were studied. The 3rd TLCP was the copolymer based onp-hydroxybenzoate (PHB) and ethylene terephthalate, known as X-7G. PBT, Vectra A, and the third TLCP were blended in the molten state, the extrudate of which was cut and injection-molded. The mechanical properties of the blends were improved by the combination of the two kinds ofTLCP. The dynamic viscoelastic analysis indicated that the thermal endurance of the ternary blends were enhanced when Vectra A was used as a major TLCP reinforcement. SEM revealed that both the binary and ternary blends were phase-separated, and the introduction of the 3rd component of TLCP was profitable for TLCP to form finer fibrils at the skin part of the sample. X-Ray diffraction analysis showed that the orientation of Vectra A fibril in the blend was raised by the addition of the 3rd TLCP, resulting in the improvement of the mechanical properties of the ternary blends. The conclusions obtained in this paper agreed with those reported in our previous paper.KEY WORDS Poly(butylene terephthalate) / Thermotropic Liquid Crystal / Ternary Blends/ Mechanical Properties/ Morphology/ X-Ray Diffraction Analysis/ In our previous paper, 1 we reported the effects of the 3rd component of TLCP on the mechanical properties of Vectra A (VA)-reinforced polycarbonate (PC). The mechanical properties of PC/VA binary blend were improved dramatically by addition of a small amount of the 3rd component of TLCP composed of PHB and PET, which was a X-7G type semi-aromatic TLCP, Rodlan of the trade name of Unitika Co. The effects were ascribed to the enhancement of orientation of TLCP ( mainly VA) in fibril, which was supported by the X-ray diffraction and the theoretical analysis based on a two-phase blend model and the SEM observation.In this paper, we continued to combine the both advantages of Vectra A and Rodlan and blended them with the matrix resin of poly-(butylene terephthalate) (PBT), forming a ternary blend system. Kimura and Porter 2 reported the thermal properties and the dynamic mechanical measurements of the binary blend of PBT/X-7G prepared by a solution precipitation method and found that both components were compatible due to the molecular interaction between PBT and the

Effects of annealing on structure and properties of TLCP/PEN/PET ternary blend fibers

“…[1][2][3][4][5][6][7][8][9] TLCPs have been used for high performance engineering plastics due to their high strength and modulus, excellent thermal endurance and chemical stability. [10][11][12][13] They consist of rigid molecular chains, and exist as ordered domains in LC state.…”

Deformation behavior and nucleation activity of a thermotropic liquid-crystalline polymer in poly(butylene terephthalate)-based composites

“…The negative values of the χ 12 and B in PBT/TLCP composites suggested that TLCP was partially compatible with PBT in the melt state due to the physical entanglement and interaction between PBT and TLCP. 39 In addition, it can be deduced that the improvement of the compatibility for PBT/TLCP composites with lower TLCP content was attributed to the interaction between PBT chains and flexible PET units in TLCP phase. However, as TLCP content was increased above 10 wt%, the number of TLCP molecules in PBT/TLCP composites was increased, and the TLCP have a tendency to link themselves because of the interaction between TLCP molecules, resulting in the less interaction between TLCP and PBT molecules.…”

Structure and properties of thermotropic liquid crystal polymer and poly(ethylene 2,6‐naphthalate) blend fibers

“…They are used in high‐performance engineering plastics because of their good mechanical properties and excellent thermal stability 1–4. The melt blending of TLCPs using conventional thermoplastics has attracted much attention due to the improved strength and tensile modulus of the resulting polymer composites 5–19. TLCPs show a high degree of order in the melt under shear and elongational flow fields, leading to deformation of the LC domains to form fibrils with high aspect ratios.…”