Effect of Poly(esterimide)s as Compatibilizers on the Physical Properties of Poly(etherimide)/Thermotropic Liquid Crystalline Polymer in-situ Composites

Abstract

ABSTRACT:This study investigates the compatibilizing effect of poly(esterimide) (PEsI) on the blend of poly-(etherimide) (Ultem 1000; Ultem from General Electric Company) and thermotropic liquid crystalline polyesteramide (Vectra B950; Vectra B from Hoechst Celanese). Two types of polyesterimide (PEsI) were prepared as compatibilizers to improve the interfacial adhesion of incompatible Ultem and Vectra B. Poly(ethyleneterephthalate) (PET) based PEsI (EI10) and poly(butyleneterephthalate) (PBT) based PEsI (BI10) including 10 mol% of the imide are prepared. The binary Vectra B/PEsI and Ultem/PEsI blends were investigated in terms of thermal properties. This revealed that EI10 is more reactive (or compatible) with Vectra B, whereas BI10 is more compatible with Ultem. The effect of compatibilizer structures on the ternary Ultem/Vectra B/PEsI blends was also studied by thermal behavior, rheological properties, and mechanical properties. These results showed that BI10, more compatible with Ultem matrix, acts as a better compatibilizer in a ternary Ultem/Vectra B/PEsI blend system than EI10, more compatible with Vectra B phase. The optimum level of the compatibilzers turned out to be about 1-2 wt% for the blend systems.KEY WORDS Polyesterimide / Interfacial Adhesion / Liquid Crystalline Polyesteramide / Polyetherimide / Compatibilizer / In recent years polymer blends in which a thermotropic liquid crystalline polymer (TLCP) dispersed in a thermoplastic matrix, so called the in-situ composite, have frequently been studied to exploit the excellent mechanical properties of the TLCP such as high tensile strength/modulus, low thermal expansion coefficient, low dielectric properties, and low moisture pick-up.1-5 Furthermore, physical properties such as thermomechanical properties, transient viscosity, crystallization behavior, morphology, and rheological properties of TLCP/isotropic polymer blends have been lively investigated. 6,7 TLCP molecules can easily line up during shearing, thereby they reduce the resistance to flow. If a spinning process is performed, moreover, the oriented fibrillar species can be obtained in the solid state due to the long relaxation time of TLCP chains. 5,8,9 In-situ composites can be produced by melt blending of two components in twin screw extruder or static mixer, followed by elongation. TLCP phases are usually deformed into microfibrils along the flow direction, and the matrix can be reinforced. In most cases, however, dispersed TLCP domain and thermoplastic matrix are immiscible. Thus, their in-situ composites show limited mechanical properties resulting from weak interfaces.To obtain enhanced physical properties of the insitu composites, improved compatibility between the matrix polymer and the reinforcing TLCP has been required. [10][11][12] It is well known that the compatibilization is a decisive factor to overcome the problems of poor dispersion and poor interfacial adhesion in the incompatible polymer blends resulting in melt flow instabilities and weak physical properties. To improve ...

Sorption and Mechanical Properties of Nitrile Rubber Compatibilized Natural Rubber—Poly (Ethylene-Co-Vinyl Acetate) Blends

“…A N INTERFACIAL AGENT, such as a block copolymer, graft copolymer, or reactive polymer is often added to immiscible blends to control the separated phase structure by modifying interfacial tension [1][2][3][4][5]. The addition of suitably selected compatibilizers to an immiscible binary blend should reduce the interfacial energy between the phases, permit finer dispersion during mixing, provide stability against gross segregation, and improve the interfacial adhesion.…”

Influence of polyamide–imide concentration on the cellular structure and thermo-mechanical properties of polyetherimide/polyamide–imide blend foams

“…Although PEI-based blends have vastly been considered in the literature, as for instance PEI with poly ether ether ketone (PEEK) [14][15][16], polycarbonate (PC) [17,18], amorphous polyamide (a-PA) [19], liquid crystalline polymer (LCP) [20][21][22][23], polyethylene terephthalate (PET) [24][25][26] or polytrimethylene terephthalate (PTT) [27], no researches have been carried out so far regarding foams made of PEI blends using the WVIPS method.…”