Main-chain thermotropic liquid-crystalline

Some particularities of the extraction of ions from an aqueous organic phase, and of the phase catalyzed polyetherification will be summarized. These will represent the fundamentals of our work on the synthesis of some novel classes of functional polymers and sequential copolymers. Examples will be provided for the synthesis of functional polymers containing only cyclic imino ethers or both cyclic imino ethers as well as their own cationic initiator attached to the same polymer backbone ABA triblock copolymers and (AB)n alternating block copolymers and a novel class of main chain thermotropic liquid crystalline polymers containing functional chain ends, i.e., polyethers. 

Three major topics of research which are based on phase transfer catalyzed reactions will be presented with examples. These refer to the synthesis of functional polymers containing functional groups (i.e., cyclic imino ethers) sensitive both to electrophilic and nucleophilic reagents a novel method for the preparation of regular, segmented, ABA triblock and (A-B)n alternating block copolymers, and the development of a novel class of main chain thermotropic liquid-crystalline polymers, i.e., polyethers. 

The homopolyestcr of 4-hydroxybcnzoic acid and its copolyestcrs with 6-hydroxy-2-naphthoic acid and with 4,4 -biphenol and tcrephthalic acid are of continuing commercial and academic interest. (1,2) From the applications side, interest stems from the high moduli and high temperature properties of these polymers, while on the fundamental side, interest arises from the main-chain thermotropic liquid crystalline... 

In the procedures below, methodology is described to facilitate medium scale (ca. 100 g) synthesis of a main-chain thermotropic liquid crystalline polymer containing ethylene glycol units as a flexible spacer between the rigid aromatic units. Two methods are described melt polymerization, and polymerization in a heat-transfer solvent with an inorganic medium (Claytone). For melt polymerization, the material is obtained as an extremely rigid solid, while in the... 

Main-Chain Thermotropic Liquid-Crystalline Polymers... 

X. Jin and T. S. Chung, Thermal decomposition behavior of main-chain thermotropic liquid crystalline polymers, Vectra A-950, B-950, and Xydar SRT-900, Journal of Applied Polymer Science, 73, 2195 (1999). 

Part I Main-Chain Thermotropic Liquid-Crystalline Polymers... i... 

Solution behavior occupies a central position in polymer science. Here we briefly review some recent results for th solution properties of main chain thermotropic liquid crystalline polymers (LCPs) dissolved in liquid crystalline solvents. We concentrate on the distortional properties of such LCPs. 

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