Rheological properties of carbon blackfilled blends of. Blends of polyether ether ketone with a thermotropic. Thermotropic liquid crystalline polymers with various alkoxy side. Other factors like strain in the polymer can cause birefringence.
Reactive compatibilization of liquid crystalline polymer. Polymer blends with a liquid crystalline polymer dispersed phase koreaaustralia rheology journaldecember 1999 vol. Rheological properties of carbon blackfilled blends of liquidcrystalline copolyester with thermoplastic polysulfone. The styreneglycidyl methacrylate sg copolymer can be used to compatibilize the immiscible and incompatible blends between polystyrene ps and liquid crystalline polymer lcp copolyester. A number of studies 24 have con centrated on elucidating the rheological, mechanical, and morphological properties of different liquid crys talline polymer blends, the liquid crystalline polyesters could form biphasic melts, coexisting isotropic and anisotropic phases in melts. This classification is based on the place in the polymer where the mesogen is inserted, i.
The tensile properties of the ppliquidcrystal lc polyester amide blend were. Liquid crystalline polymers can be classified into main chain, side chain and combined figure 3. Electrically conductive compounds of polycarbonate, liquid crystalline polymer, and multiwalled carbon nanotubes. Liquid crystal polymer an overview sciencedirect topics. The subject of molecu lar composites, though discussed is not covered rig orously in this article. Us55990a polyetherimideliquid crystalline polymer blends. Our recent experimental results have shown that a miscible blend containing a liquid crystalline polymer lcp and an amorphous copolymer, both capable of selfassociation and interassociation by hydrogenbonding, can be created by slight structural modification of the amorphous polymer. Blends of a thermotropic liquid crystalline polymer lcp with polypropylene pp were injection. This paper describes the reactive compatibilization of blends of a wholly aromatic thermotropic copolyester liquid crystalline polymer tlcp with random copolymers of ethylene and acrylic acid. In recent years, many areas of research relating to the development of new and improved commercial products made from liquid crystal polymers lcps and. Two block copolymers, polysulfonepolyethylene terephthalate psfpet and polysulfonepolyhydroxybenzoate psfphb, were synthesized in order to compatibilize the blends of polysulfone psf and a semiaromatic thermotropic liquid crystalline polymer tlcpa1. Polymer blends with a liquid crystalline polymer dispersed phase. Preface the subject of liquid crystalline polymers lcps transcends classical polymer chemistry and physics, and it extends the conventional boundaries of rheology and processing. Liquid crystal polymers are present in melted liquid or solid form.
The 2006 edition of this authoritative guide on liquid crystalline polymer lcp science was produced in response to the wealth of new material generated in the field. Current advances in the carbon nanotubethermotropic main. The morphology, crystallization, and melting behavior. Liquid crystallinity in polymers may occur either by dissolving a polymer in a solvent lyotropic liquidcrystal polymers or by heating a polymer above its glass or melting transition point thermotropic liquidcrystal polymers. Structure properties relations of polypropylene liquid crystalline polymer blends macromol. Introduction during the past two decades, there have been numerous attempts to exploit the superior mechanical properties of thermotropic liquid crystalline polymers tlcp in polymer blends. Improved blends of polyetherimide liquid crystalline polymer are provided. Blends of polyether ether ketone with a thermotropic liquid. Read the mechanical properties of ternary liquid crystalline polymer blends, polymer on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
Phase behavior and phase separation in blends of a liquid. The epoxy functional groups of the egma copolymer can react with the carboxylic acid andor hydroxyl endgroups of the liquid comptalline copolyester. In summary, we have developed and investigated a lattice model for semiflexible polymers that allows us to control the formation of liquid crystalline regions in melts and blends. Electrically conductive compounds of polycarbonate, liquid. Liquid crystalline polymer lcp blends have been i studied extensively in recent years. Over the past few decades, the crystallization behavior in miscible crystallineamorphous polymer blends has been extensively investigated 1. Studies on blends of a thermotropic liquid crystalline. A detailed description of this equipment was published elsewhere 41, 42 blends of pet and a liquid crystalline polymer as the minor phase are prepared on the abovementioned extruder. Pdf the blends of polypropylene pp with glass filled thermotropic liquid crystalline polymer lcpg have been prepared by melt mixing techniques at. Reactive compatibilization and inline morphological. Thermotropic liquid crystalline polymers tlcps represent a class of. The structure and properties of polyamideliquid crystal polymer.
Lec1 introduction to polymer blend types of polymer blends. Orientational behavior of polymer blends containing a liquid crystalline. Polarized optical microscopy a quick way to see if a polymer is crystalline. We discuss flexible, semiflexible and rigid polymers. Phase equilibria of flexible polymer and monomer liquid. The blending was performed via a common solution and rapid precipitation. A2, 100 bureau dr stop 8542, national institute of standards and technology, gaithersburg, md 208998542 abstract the morphology of a compatibilized polyethylene terephthlate and. Both optical microscopy and light scattering are employed for morphological measurements. In addition, smallangle light scattering sals and smallangle xray scattering saxs are used to study the morphology of crystalline amorphous polymer blends.
The in situformed egmaglcp copolymer tends to reside along the. Pdf structure properties relations of polypropyleneliquid. Rheology of polypropyleneliquid crystalline polymer. High molar mass liquid crystalline polymers have been primarily used in polymer blends as processing aids and as an incipient reinforcing phase for self.
The results also show that an optimum amount of intermolecular hbonding can be formed in the blend by. Characterization of polymerliquid crystal blends article pdf available in journal of the serbian chemical society 663 march 2001 with 67 reads how we measure reads. Rheology of polypropyleneliquid crystalline polymer blends. High molar mass liquid crystalline polymers have been primarily used in polymer blends as processing aids and as an incipient reinforcing phase for selfreinforced materials. Processing of liquid crystal polymers and blends springerlink.
Liquid crystallinity in polymers may occur either by dissolving a polymer in a solvent lyotropic liquid crystal polymers or by heating a polymer above its glass or melting transition point thermotropic liquid crystal polymers. Us5541240a method for making blends of liquid crystalline. Though polymer blends with smallmolecule nematic liquid crystal phases have been investigated primarily for displays, related materials containing smallmolecule smectic phases have not been reported. Pdf in situ compatibilized polypropyleneliquid crystalline.
Pdf structure properties relations of polypropylene. Barrier properties of blends based on liquid crystalline. Miscibility, crystallinity and morphology of polymer. Optimizing hydrogenbonding in creating miscible liquid.
While in most polymer blends compatibilization leads to finely dispersed. The lack of sufficient experimental data in polymerpolymer and polymerdiluent liquid crystalline systems motivated us to explore this area further. A hierarchy of structures volume 255 witold brostow, michael hess. Structure properties relations of polypropylene liquid. Pdf characterization of polymerliquid crystal blends. Liquid crystalline polymer blends with stabilized viscosity. Twocomponent blends of polymer liquid crystals with polysulfone or polypropylene have been investigated. A thermotropic liquid crystalline polymer lcp was blended with polycarbonate. In this series of reports, blends of pbt with lcp content down to 0. Thus, the study of the kinetics of crystallization is necessary for optimizing the process conditions and establishing the structure property correlations in polymers.
Miscibility, crystallinity and morphology of polymer blends. This is in comparison to the molecular structure of abs and nylon which. Joseph e g, wilkes g l, baird d g, preliminary thermal and structural studies of blends based on a thermotropic liquid crystalline copolyester and polyethylene terephtalate. In situ compatibilized polypropyleneliquid crystalline polymer blends. The miscibility of homopolymercopolymer blends has been successfully. Liquidcrystalline ordering in semiflexible polymer melts. Electrically conductive compounds of polycarbonate. Liquid crystalline polymer an overview sciencedirect topics. Also included are studies of blends of polymers and low molar mass liquid crystals, for which there are sev eral interesting applications. Pdf mechanical and morphological study of polyphenylene. Read the mechanical properties of ternary liquidcrystalline polymer blends, polymer on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at. Introduction the selfassembly of soft matter systems provides a powerful tool to create complex hierarchical materials 1,2. In situ reinforcement of polypropylene with liquidcrystalline polymers.
In addition, smallangle light scattering sals and smallangle xray scattering saxs are used to study the morphology of crystallineamorphous polymer blends. The blend behaviour of a thermoplast polycaprolacton and a liquid crystalline polyester was investigated. Over the past few decades, the crystallization behavior in miscible crystalline amorphous polymer blends has been extensively investigated 1. The lcp was anticipated to produce fibrillar domains in. Liquid crystalline polymer an overview sciencedirect. The most definitive and update reference available on the subject, the twovolume set polymer blends. Blends of lcpg with pp were prepared in a brabender plasticorder pl 2200mixern50e with rotor.
The phase behavior and thermally induced phase separation in blends of polystyrene. Formulation and performanceexplores and summarizes the recent progress made in polymer blend technology through the use of carefully selected contributions from todays foremost authorities from around the world. The configurations generated in this way will be used in the future to study charge transport properties of. Available formats pdf please select a format to send.
A flowinduced phase inversion in immiscible polymer blends. A chapter on liquid biopolymers has been introduced, whilst the indepth discussion on. The subject of liquid crystalline polymers lcps transcends classical polymer chemistry and physics, and it extends tile conventional boundaries of theology and processing. Xray scattering can determine precise crystal structure. Liquid crystalline polymer 1 liquid crystalline polymers lcps are widely used in many types of electric and electronic parts due to their superiority in high heat solder resistance, hightemperature strength, dimensional stability, overall good chemical resistance, low flammability and low water absorption. The background liquid crystals lc are substances that exhibit a phase of. The epoxy functional groups present in the sg copolymer can react with the carboxylic andor the hydroxyl terminal groups of the lcp at interface to form. Blends of poly pphenylene sulphide pps and a liquid crystalline polymer lcp were made by two methods. Blends of thermotropic liquid crystalline polymer lcpa950, based on a copolyester of hydroxynapthoic acid and hydroxybenzoic acid with an engineering thermoplastic. Polyethylene terephthalate pet matrix was modified by blending with a specially prepared thermotropic liquid crystalline polymer tlcp, in the hope to make the in situ composite during fiber spinning. Lcps have a highly crystalline molecular chain in comparison to most common polymers such as abs and nylon. The polymers are mixed under shearing conditions for a time. Effect of temperature on the creep of a thermotropic liquid crystalline polymer.
Properties of these new materials are, on the one hand, reminiscent of amorphous metals, while simultaneously exhibiting attributes of organic single crystals. Blends of thermotropic liquid crystalline polymers and isotropic meltprocessable polymers are made by extruding a molten stream of either a thermotropic liquid crystalline polymer or an isotropic polymer through a heated mixing zone and feeding the other of the two polymers into the stream of the first polymer in the mixing zone. In situ compatibilized polypropyleneliquid crystalline. It takes the reader through the theoretical underpinnings to realworld applications of lcp technology in a logical, wellintegrated manner. Introduction p olymer blends containing a liquid crystalline. Cangianob adepartment of chemical engineering and polymer science program, university of connecticut, storrs, ct 0626936, usa bhoechst research, summit, nj 07901, usa received 21 february 1999. A flowinduced phase inversion in immiscible polymer blends containing a liquid crystalline polymer studied by in situ optical microscopy. Blends of semicrystalline polymers polyethylene adipate and two polyesterure thanes with liquid crystal cholesteryl palmitate with different compositions. The nonisothermal crystallization behaviour of polyphenylene sulfide pps in blends with thermotropic liquid crystalline polymer tlcp was studied by. Structureproperty relationship in fibers spun from poly. The background liquid crystals lc are substances that exhibit a phase of matter intermediate to the isotropic liquid. The blends exhibited a twophase structure with one phase being the pure thermoplast and the second a mixture of the thermoplast with the liquid crystalline polymer lcp. Request pdf the structure and properties of polyamideliquid crystal polymer blends melt blended polyamide paliquid crystal polymer lcp blends.
The blends are obtained by melt blending amine terminated polyetherimide resin with liquid crystalline polyester resins and exhibit improved levels of tensile strength compared to blends of phthalic anhydride capped polyetherimide resin with liquid crystalline polyester resin. Liquid crystalline polymers can be divided into two types. In the present study, we report the phase equilibria in a nematic monomer and a nematic flexible polymer within the total phase diagram. Crystallinity in polymers university of texas at austin. Crystallization behavior and higherorder structure in. Polymer blends with a liquid crystalline polymer dispersed. Front matter liquid crystalline polymers the national. Rheology and morphology of smectic liquid crystalpolymer. Reactive compatibilization of blends containing liquid.
Polyphenylene sulfideliquid crystalline polymer blends. It has been found that the tlcp did not fibrillate in the pet matrix at any concentration under given processing conditions, although it did in the polycarbonate matrix. Compatibility of block copolymers on blends of polysulfone. In situ compatibilized polypropylene liquid crystalline polymer blends. Barrier properties of blends based on liquid crystalline polymers and polyethylene terephthalate international journal of polymeric materials and polymeric biomaterials. Reactive compatibilization of blends containing liquid crystalline polymers h. Liquid crystals lc two types thermotropic phase transitions occur as temperature changes aromatic polyesters lyotropic phase transitions are a function of concentration and temperature aramids mesophases nematic smectic a, smectic c others liquid nematic smectic a smectic c crystalline wang, x zhou, q. The authoritative resource on polymer blends for the twentyfirst century. Mechanical properties of injection moulded blends of polypropylene. Rheology and morphology of smectic liquid crystalpolymer blends.
More complex polymer architectures are also possible. The blends of polypropylene pp with glass filled thermotropic liquid crystalline polymer lcpg have been prepared by melt mixing techniques at different blend ratios. Reactive compatibilization and inline morphological analysis. Crystallization of polybutylene terephthalate blends. In both types of liquid crystalline polymers, gas permeability is dependent on the ordered packing of the polymer chains. The structural organization at different scales, from atomistic to mesoscopic levels.
The mechanical properties of ternary liquidcrystalline. Liquidcrystal polymers are present in meltedliquid or solid form. They exhibit a semi rigid, nearly linear, stacked orientation of molecules which stay highly ordered even in the liquid crystal phase as shown in fig. Improved blends of polyetherimideliquid crystalline polymer are provided. In solid form the main example of lyotropic lcps is the commercial aramid known as kevlar. A psfpet block copolymer exhibits better compatibility. A thermotropic liquid crystalline polymer lcp was blended with polycarbonate pc and multiwalled carbon nanotube cnt with the goal of improving electrical conductivity and mechanical properties over pc. The structure and phase transitions in polymer blends. The morphology and rheology of polymer blends containing a liquid crystalline copolyester. A flowinduced phase inversion in immiscible polymer.
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