Miscibility and Mechanical Properties of Poly(ether imide)/Liquid Crystalline Poly(ester imide) Blends

Ryu, Chong Kul; Seo, Yongsok; Hwang, Seung Sang; Hong, Soon Man; Park, Tae Suk; Kim, Kwang Ung

doi:10.3139/217.940266

Cited by 5 publications

References 14 publications

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Liquid Crystalline Composite

Isayev

2012

Wiley Encyclopedia of Composites

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A review of novel technologies for manufacturing composites involving liquid crystalline polymers (LCPs) is presented. In particular, this review provides a classification scheme of various types of LCPs, with a special emphasis paid to the history, key approaches, milestones in developments of thermotropic LCPs, and their commercialization. Methods of characterization of LCPs by optical and electron microscopy, X‐ray diffraction, NMR, light scattering, and thermal, rheological, and mechanical techniques are discussed. The development of the concept of self‐reinforced or in situ composites based on blending LCPs with flexible‐chain polymers and LCPs with other LCPs is presented. In these composites, the dispersed fibrous reinforcing LCP species in polymer matrices are not actually present before the processing of the resin, but come into existence during the processing step. Various aspects of manufacturing of these composites are discussed including methods of mixing and compounding, transition temperatures, different factors governing LCP fibrillations, effects of LCP on crystallization of thermoplastic matrices, rheology of composites, and the use of LCP as a processing aid for thermoplastics. Special attention is paid to manufacturing and mechanical properties of the composites based on LCP/thermoplastic, LCP/LCP and ternary blends, and LCP/thermoplastic and LCP/LCP laminates. The effect of compatibilization and anisotropy of composites are also considered along with proposed approaches to reduce their anisotropy. Finally, various existing and future possibilities for industrial applications of self‐reinforced composites are discussed.

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Liquid Crystalline Composite

Isayev

2012

Wiley Encyclopedia of Composites

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Reactive extrusion of in‐situ composite based on PET and LCP blends

Hong

Hwang

Seo

et al. 1997

Polymer Engineering & Sci

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The “in‐situ” compatibilization for a PET/LCP blend via transesterification reactions in a twin‐screw extruder having a very short residence time is investigated through thermal, rheological, and mechanical studies. Inclusion of a small amount of liquid crystalline polymer (LCP) enhanced the crystallization rate of the poly(ethylene terephthalate) (PET) matrix. It acted as a nucleating agent. LCP lowered the blend viscosity above Tcn (crystalline‐nematic transition temperature), working as a processing aid. However, the addition of dibutyltindilaurate (DBTDL) as a reaction catalyst was found to increase the viscosity of the blends, diminish the size of the dispersed phase, enhance its adhesion with the matrix, and lead to an increase of mechanical properties of two immiscible phases. Hence DBTDL is helpful in producing a reactive compatibilizer by reactive extrusion at the interface of this polyester blend system. The optimum catalyst amount turned out to be about 500 ppm when the reaction proceeds in 90/10 PET/LCP polyester blend systems. Its effect on the mechanical properties is discussed in detail. The structural change of reactive blend was identified by H1 NMR and wide angle X‐ray diffraction patterns.

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