Structureproperty relationship in fibers spun from poly. Blends of thermotropic liquid crystalline polymer lcpa950, based on a copolyester of hydroxynapthoic acid and hydroxybenzoic acid with an engineering thermoplastic. 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. Blends of polyether ether ketone with a thermotropic. It takes the reader through the theoretical underpinnings to realworld applications of lcp technology in a logical, wellintegrated manner. Miscibility, crystallinity and morphology of 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 polyether ether ketone with a thermotropic liquid. Crystallization of polybutylene terephthalate blends. Reactive compatibilization and inline morphological analysis. In addition, smallangle light scattering sals and smallangle xray scattering saxs are used to study the morphology of crystalline amorphous polymer blends.
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. 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 results also show that an optimum amount of intermolecular hbonding can be formed in the blend by. Optimizing hydrogenbonding in creating miscible liquid. Also included are studies of blends of polymers and low molar mass liquid crystals, for which there are sev eral interesting applications. This classification is based on the place in the polymer where the mesogen is inserted, i.
The structure and phase transitions in polymer blends. Blends of poly pphenylene sulphide pps and a liquid crystalline polymer lcp were made by two methods. Reactive compatibilization of liquid crystalline polymer. 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.
Pdf mechanical and morphological study of polyphenylene. Crystallinity in polymers university of texas at austin. Miscibility, crystallinity and morphology of polymer blends. Blends of a thermotropic liquid crystalline polymer lcp with polypropylene pp were injection. Liquid crystal polymers are present in melted liquid or solid form. Us55990a polyetherimideliquid crystalline polymer blends. Electrically conductive compounds of polycarbonate. We discuss flexible, semiflexible and rigid polymers. The nonisothermal crystallization behaviour of polyphenylene sulfide pps in blends with thermotropic liquid crystalline polymer tlcp was studied by. The miscibility of homopolymercopolymer blends has been successfully. Current advances in the carbon nanotubethermotropic main.
Thus, the study of the kinetics of crystallization is necessary for optimizing the process conditions and establishing the structure property correlations in polymers. The blend behaviour of a thermoplast polycaprolacton and a liquid crystalline polyester was investigated. Lcps have a highly crystalline molecular chain in comparison to most common polymers such as abs and nylon. 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. Liquid crystalline polymer an overview sciencedirect topics.
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 mechanical properties of ternary liquidcrystalline. 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. Electrically conductive compounds of polycarbonate, liquid.
Liquidcrystal polymers are present in meltedliquid or solid form. This is in comparison to the molecular structure of abs and nylon which. Thermotropic liquid crystalline polymers tlcps represent a class of. 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. In this series of reports, blends of pbt with lcp content down to 0. 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. While in most polymer blends compatibilization leads to finely dispersed. Other factors like strain in the polymer can cause birefringence. The polymers are mixed under shearing conditions for a time.
Rheology and morphology of smectic liquid crystalpolymer blends. The lack of sufficient experimental data in polymerpolymer and polymerdiluent liquid crystalline systems motivated us to explore this area further. Barrier properties of blends based on liquid crystalline polymers and polyethylene terephthalate international journal of polymeric materials and polymeric biomaterials. More complex polymer architectures are also possible. Pdf structure properties relations of polypropyleneliquid. Rheology of polypropyleneliquid crystalline polymer blends. A2, 100 bureau dr stop 8542, national institute of standards and technology, gaithersburg, md 208998542 abstract the morphology of a compatibilized polyethylene terephthlate and.
Reactive compatibilization and inline morphological. Barrier properties of blends based on liquid crystalline. Crystallization behavior and higherorder structure in. The styreneglycidyl methacrylate sg copolymer can be used to compatibilize the immiscible and incompatible blends between polystyrene ps and liquid crystalline polymer lcp copolyester. The structure and properties of polyamideliquid crystal polymer. Rheology of polypropyleneliquid crystalline polymer. Pdf structure properties relations of polypropylene. 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. 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 recent years, many areas of research relating to the development of new and improved commercial products made from liquid crystal polymers lcps and. Us5541240a method for making blends of liquid crystalline. Introduction p olymer blends containing a liquid crystalline. Polyphenylene sulfideliquid crystalline polymer blends. 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. Preface the subject of liquid crystalline polymers lcps transcends classical polymer chemistry and physics, and it extends the conventional boundaries of rheology and processing. The in situformed egmaglcp copolymer tends to reside along the. In solid form the main example of lyotropic lcps is the commercial aramid known as kevlar. Blends of semicrystalline polymers polyethylene adipate and two polyesterure thanes with liquid crystal cholesteryl palmitate with different compositions. Structure properties relations of polypropylene liquid crystalline polymer blends macromol. 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. Reactive compatibilization of blends containing liquid. 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. A flowinduced phase inversion in immiscible polymer blends.
Improved blends of polyetherimideliquid crystalline polymer are provided. Available formats pdf please select a format to send. Liquid crystalline polymer an overview sciencedirect. 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. A psfpet block copolymer exhibits better compatibility. 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. Phase behavior and phase separation in blends of a liquid. Twocomponent blends of polymer liquid crystals with polysulfone or polypropylene have been investigated. In situ compatibilized polypropylene liquid crystalline polymer blends. The most definitive and update reference available on the subject, the twovolume set polymer blends. Pdf in situ compatibilized polypropyleneliquid crystalline.
The blends of polypropylene pp with glass filled thermotropic liquid crystalline polymer lcpg have been prepared by melt mixing techniques at different blend ratios. A thermotropic liquid crystalline polymer lcp was blended with polycarbonate. 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. The phase behavior and thermally induced phase separation in blends of polystyrene. Polymer blends with a liquid crystalline polymer dispersed phase. Polarized optical microscopy a quick way to see if a polymer is crystalline. Rheological properties of carbon blackfilled blends of. 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. A chapter on liquid biopolymers has been introduced, whilst the indepth discussion on.
Mechanical properties of injection moulded blends of polypropylene. Orientational behavior of polymer blends containing a liquid crystalline. Compatibility of block copolymers on blends of polysulfone. In addition, smallangle light scattering sals and smallangle xray scattering saxs are used to study the morphology of crystallineamorphous polymer blends. In situ compatibilized polypropyleneliquid crystalline polymer blends. Electrically conductive compounds of polycarbonate, liquid crystalline polymer, and multiwalled carbon nanotubes. In both types of liquid crystalline polymers, gas permeability is dependent on the ordered packing of the polymer chains. Studies on blends of a thermotropic liquid crystalline. Introduction the selfassembly of soft matter systems provides a powerful tool to create complex hierarchical materials 1,2. Liquidcrystalline ordering in semiflexible polymer melts. 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 morphology and rheology of polymer blends containing a liquid crystalline copolyester. The epoxy functional groups of the egma copolymer can react with the carboxylic acid andor hydroxyl endgroups of the liquid comptalline copolyester. Liquid crystalline polymer lcp blends have been i studied extensively in recent years. Improved blends of polyetherimide liquid crystalline polymer are provided.
The authoritative resource on polymer blends for the twentyfirst century. Structure properties relations of polypropylene liquid. The background liquid crystals lc are substances that exhibit a phase of. 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. Liquid crystalline polymers can be classified into main chain, side chain and combined figure 3.
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. Pdf the blends of polypropylene pp with glass filled thermotropic liquid crystalline polymer lcpg have been prepared by melt mixing techniques at. The subject of molecu lar composites, though discussed is not covered rig orously in this article. The tensile properties of the ppliquidcrystal lc polyester amide blend were. 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. Thermotropic liquid crystalline polymers with various alkoxy side. Request pdf the structure and properties of polyamideliquid crystal polymer blends melt blended polyamide paliquid crystal polymer lcp blends. The structural organization at different scales, from atomistic to mesoscopic levels. Xray scattering can determine precise crystal structure. The configurations generated in this way will be used in the future to study charge transport properties of. 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. Liquid crystalline polymers can be divided into two types.
A flowinduced phase inversion in immiscible polymer. Polymer blends with a liquid crystalline polymer dispersed phase koreaaustralia rheology journaldecember 1999 vol. Liquid crystalline polymer blends with stabilized viscosity. Polymer blends with a liquid crystalline polymer dispersed. Liquid crystal polymer an overview sciencedirect topics. The morphology, crystallization, and melting behavior. Phase equilibria of flexible polymer and monomer liquid. 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 lcp was anticipated to produce fibrillar domains in.
Reactive compatibilization of blends containing liquid crystalline polymers h. 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. Over the past few decades, the crystallization behavior in miscible crystallineamorphous polymer blends has been extensively investigated 1. The blending was performed via a common solution and rapid precipitation. Pdf characterization of polymerliquid crystal blends. Rheological properties of carbon blackfilled blends of liquidcrystalline copolyester with thermoplastic polysulfone. In the present study, we report the phase equilibria in a nematic monomer and a nematic flexible polymer within the total phase diagram.
Blends of lcpg with pp were prepared in a brabender plasticorder pl 2200mixern50e with rotor. 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. Over the past few decades, the crystallization behavior in miscible crystalline amorphous polymer blends has been extensively investigated 1. The subject of liquid crystalline polymers lcps transcends classical polymer chemistry and physics, and it extends tile conventional boundaries of theology and processing. Lec1 introduction to polymer blend types of polymer blends. A hierarchy of structures volume 255 witold brostow, michael hess. Effect of temperature on the creep of a thermotropic liquid crystalline polymer. Front matter liquid crystalline polymers the national. 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. Processing of liquid crystal polymers and blends springerlink. Rheology and morphology of smectic liquid crystalpolymer. 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. The background liquid crystals lc are substances that exhibit a phase of matter intermediate to the isotropic liquid. In situ reinforcement of polypropylene with liquidcrystalline polymers.
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