liquidcrystalpolymer.pptVIP

3.Liquid crystal polymers 材料学院 张英强 Contents Liquid crystals: The fourth state of matter The classifications of liquid crystals According to the molecular characteristics main chains liquid crystal molecules , side chains liquid crystal molecules… According to configuration of liquid crystal nematic, cholesteric and smectic liquid crystal … According to forming processes of liquid crystal Lyotropic LCPs, Thermotropic LCPs,… Methods to study liquid crystals Differential Scanning Calorimetry (DSC) Determine transition temperatures… Polarizing microscopy textures X-ray and neutron scattering technique identifying phases and arrangements of molecules Differential Scanning Calorimetry (DSC) Liquid crystal polymers Polymers that exhibit liqiuid crystallinity, either in the melt or in their solutions, typically consist of comparatively rigid structures that confer high extension on the backbone of the macromolecule. Main-chain LCPs(MLCPS) Thermotropic main-chain LCPs have unique combination of properties from both LC and conventional thermoplastic states. these include: melt processibility high mechanical properties low moisture take-up excellent thermal chemical resistance Main-chain LCPs(MLCPS) With the successful development of these LCPs and recognition of their unique properties, comprehensive research and development have been carried out by both academia and industry Mainly concentrated on: the synthesis of new LCPs Their rheology behavior morphology compatibility processing of LCPs and blends The problems of MCLCP Most monomers for LCP syntheses are highly crystalline, but do not have characteristics of liquid crystallinity high regularity poor processibility Modification of Main-Chain LCPs Modifications of main-chain LCPs suitable for conventional processing equipment, without compromising the uniqueness of LC characteristics and the superior mechanical properties, hav