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Syndiotactic Polystyrene (syndiotactic + polystyrene)
Selected AbstractsSelective Guest Uptake from Solvent Mixtures in the Clathrate Phase of Syndiotactic PolystyreneMACROMOLECULAR RAPID COMMUNICATIONS, Issue 22 2004Yukihiro Uda Abstract Summary: Selective absorption uptake during the guest-exchange processes in the , form of syndiotactic polystyrene (sPS) was confirmed by IR spectroscopy. When films of the , form were immersed in hexane/decane or chloroform/decane mixtures, decane molecules were incorporated preferentially in the , form. Sorbate uptake by the , form was greatly accelerated when the sorbate was mixed with a solvent penetrable to the amorphous region of sPS. Concentration changes in a , -form film during sorption processes: sorption of a chloroform(D)/decane(H) mixture (1:1 molar ratio). [source] Thermally-Induced Phase Transitions in the Uniaxially-Oriented , Form of Syndiotactic PolystyreneMACROMOLECULAR SYMPOSIA, Issue 1 2006E. Bhoje Gowd Abstract The empty , (,e) form of uniaxially-oriented syndiotactic polystyrene (sPS) samples were obtained by extracting the solvent molecules from the , form of sPS and solvent complex in acetone and methanol. Temperature dependence of the X-ray fiber diagrams starting from the uniaxially-oriented ,e and , form has been measured successfully at various temperatures for the first time. The transition behavior was traced clearly by separating the equatorial and layer line reflections. The ,e form transformed to the , form via an intermediate form. The intermediate form is speculated to take disordered structure due to the empty cavities present in the ,e form. Calorimetric studies showed an endotherm followed by an exotherm during this phase transition, which is consistant with such a speculation. On the other hand the , form transformed to the , form directly without passing through the intermediate form or ,e form. During the , to , phase transition the solvent molecules evaporate through the columnar structure in a broad range of temperature, allowing the transition to occur smoothly. [source] ChemInform Abstract: A New Homogeneous Polymer Support Based on Syndiotactic Polystyrene and Its Application in Palladium-Catalyzed Suzuki,Miyaura Cross-Coupling Reactions.CHEMINFORM, Issue 9 2010Jihoon Shin Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Syndiotactic polystyrene: Process and applicationsADVANCES IN POLYMER TECHNOLOGY, Issue 3 2006Jürgen Schellenberg Abstract In this review, a summary is provided of the manufacturing process for syndiotactic polystyrene together with an overview of applications of syndiotactic polystyrenes, including selected examples of typical applications. The manufacturing process of syndiotactic polystyrene, consists of several basic sections: catalyst premix preparation, monomer treatment, polymerization reaction using a powder bed reactor together with an evaporative cooling system, devolatilization and extrusion, and finally finishing, including cooling and crystallization of the strands. This process is suitable for providing a wide range of syndiotactic polystyrenes comprising homopolymers, with a broad range of melt flow rates as well as copolymers of various comonomer contents, leading to products with various melting temperatures. Essential relationships and correlations of the separate process stages are demonstrated, in addition to useful analytical methods to control the process. These polymers' unique combination of heat resistance, chemical resistance, and electrical properties has led to their successful application in automotive, electrical and electronics, consumer and industrial uses. © 2006 Wiley Periodicals, Inc. Adv Polym Techn 25:141,151, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20069 [source] Orientation of Syndiotactic Polystyrene Crystallized in Cylindrical NanoporesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 3 2009Hui Wu Abstract Syndiotactic polystyrene (sPS) nanorods with different diameters have been prepared by using anodic aluminum oxide templates, and the orientation of the sPS crystals in the nanorods has been investigated by FT-IR spectroscopy. It is found that the c axis of the ,, crystals preferentially oriented perpendicular to the axis of the nanorod, and the degree of orientation is lower as the diameter of the nanorod decreases. This unexpected result is attributed to nuclei formed at the surface of the nanopores and their subsequent growth, in addition to the preferential growth compatible with the pore direction by the nuclei formed in the bulk film and in the nanorods. [source] Reactive processing of syndiotactic polystyrene with an epoxy/amine solvent systemMACROMOLECULAR SYMPOSIA, Issue 1 2003Jaap Schut Abstract Syndiotactic polystyrene (sPS) is a new semi-crystalline thermoplastic which is believed to fill the price-performance gap between engineering and commodity plastics. In order to reduce the high processing temperature of sPS (>290°C), an epoxy-amine model system was used as a reactive solvent. Such a processing aid can be used to achieve a 50 to 500 fold lowering of the melt viscosity. When initially homogeneous solutions of sPS in a stoechiometric epoxy-amine mixture are thermally cured, Reaction Induced Phase Separation (RIPS) takes place, leading to phase separated thermoplastic-thermoset polymer blends. We focus our study on low (wt% sPS < 20%) and high concentration blends (wt% sPS > 60%) prepared by two processing techniques (mechanical stirring in a laboratory reactor or internal mixer/ reactive extrusion respectively). These blends have different potential interests. Low concentration blends (sPS domains in an epoxy-amine matrix) are prepared to create new, tunable blend morphologies by choosing the nature of the phase separation process, i.e. either crystallisation followed by polymerization or polymerization followed crystallisation. High concentration blends (sPS matrix containing dispersed epoxy-amine particles after RIPS) are prepared to facilitate the extrusion of sPS. In this case, the epoxy amine model system served as a reactive solvent. The time to the onset of RIPS is in the order of 7-9 min for low concentration blends, while it increases to 20-45 min for high concentration samples, as the reaction rates are substantially slowed down due to lower epoxy and amine concentrations. During the curing reaction the melting temperature of sPS in the reactive solvent mixture evolves back from a depressed value to the level of pure sPS. This indicates a change in the composition of the sPS phase, caused by (complete) phase separation upon reaction. We conclude that our epoxy amine system is suited for reactive processing of sPS, where final properties depend strongly on composition and processing conditions. [source] DGEBA monomer as a solvent for syndiotactic polystyreneMACROMOLECULAR SYMPOSIA, Issue 1 2003Jaap Schut Abstract Syndiotactic polystyrene (sPS) has to be processed at high temperatures (i.e. >290°C due to its melting point of 270°C), which approaches its degradation temperature. We aim to facilitate the processing of sPS by lowering its melt temperature and viscosity with a curable epoxy/amine model system as reactive solvent, which will result in a thermoplastic-thermoset polymer blend. As a first step we therefore investigated the melting behaviour of sPS in epoxy monomer, established its phase diagram, and investigated the crystalline form of sPS in these mixtures. DGEBA epoxy monomer is found to be a solvent for syndiotactic polystyrene at temperatures above 220°C. The DGEBA-sPS phase diagram was established by means of DSC, on the basis of crystallization and melting peaks. The form of the curve in the phase diagram indicates that DGEBA is a poor solvent for sPS. In WAXS studies of blends only the , crystalline form was detected, not the , form, thus no sPS-DGEBA polymer-solvent compounds (clathrates) were detected. However, DGEBA can still serve as a monomer for improved processing as it depresses the crystallization temperature by 20 to 60 K upon addition of 20 to 90 wt% DGEBA respectively, while a 16 to 45 K melting peak depression can be observed by adding 20 to 90 wt% DGEBA. [source] The continuous cooling transformation (CCT) as a flexible tool to investigate polymer crystallization under processing conditionsADVANCES IN POLYMER TECHNOLOGY, Issue 2 2009V. Brucato Abstract An experimental route for investigating polymer crystallization over a wide range of cooling rates (from 0.01 to 1000°C/s) and pressures (from 0.1 to 40 MPa) is illustrated, using a method that recalls the approach adopted in metallurgy for studying structure development in metals. Two types of experimental setup were used, namely an apparatus for fast cooling of thin films (100,200 ,m thick) at various cooling rates under atmospheric pressure and a device (based on a on-purpose modified injection molding machine) for quenching massive samples (about 1,2 cm3) under hydrostatic pressure fields. In both cases, ex situ characterization experiments were carried out to probe the resulting structure, using techniques such as density measurements and wide-angle x-ray diffraction (WAXD) patterns. The cooling mechanism and temperature distribution across the sample thickness were analyzed. Results show that the final structure is determined only by the imposed thermal history and pressure. Experimental results for isotactic polypropylene (iPP), poly(ethylene terephthalate) (PET), polyamide 6 (PA6), and syndiotactic polystyrene (sPS) are reported, showing the reliability of this experimental approach to assess not only quantitative information but also a qualitative description of the crystallization behavior of different classes of semicrystalline polymers. The present study gives an opportunity to evaluate how the combined effect of the cooling rate and pressure influences the crystallization kinetics for various classes of polymer of commercial interest. An increase in the cooling rate translates into a decrease in crystallinity and density, which both experience a sudden drop around the specific "crystallizability" (or "critical cooling rate") of the material examined. The exception is sPS where competition among the various crystalline modifications determines a minimum in the plot of density vs. cooling rate. As for the effect of pressure, iPP exhibits a "negative dependence" of crystallization kinetics upon pressure, with a decrease of density and degree of crystallinity with increasing pressure, owing to kinetic constraints. PA6 and PET, on the other hand, due to thermodynamic factors resulting in an increase in Tm with pressure, exhibits a "positive dependence" of crystallization kinetics upon pressure. Finally, recent original results concerning sPS have shown that the minimum in the density vs. cooling rate curve shifts toward larger cooling rates upon increasing pressure. © 2009 Wiley Periodicals, Inc. Adv Polym Techn 28:86,119, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20151 [source] Syndiotactic polystyrene: Process and applicationsADVANCES IN POLYMER TECHNOLOGY, Issue 3 2006Jürgen Schellenberg Abstract In this review, a summary is provided of the manufacturing process for syndiotactic polystyrene together with an overview of applications of syndiotactic polystyrenes, including selected examples of typical applications. The manufacturing process of syndiotactic polystyrene, consists of several basic sections: catalyst premix preparation, monomer treatment, polymerization reaction using a powder bed reactor together with an evaporative cooling system, devolatilization and extrusion, and finally finishing, including cooling and crystallization of the strands. This process is suitable for providing a wide range of syndiotactic polystyrenes comprising homopolymers, with a broad range of melt flow rates as well as copolymers of various comonomer contents, leading to products with various melting temperatures. Essential relationships and correlations of the separate process stages are demonstrated, in addition to useful analytical methods to control the process. These polymers' unique combination of heat resistance, chemical resistance, and electrical properties has led to their successful application in automotive, electrical and electronics, consumer and industrial uses. © 2006 Wiley Periodicals, Inc. Adv Polym Techn 25:141,151, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20069 [source] Hydrophilic functionalization of syndiotactic polystyrene via a combination of electrophilic bromination and Suzuki,Miyaura reactionJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 19 2010Jihoon Shin Abstract Postfunctionalization of high-molecular-weight syndiotactic polystyrene (sPS) was achieved via combination of electrophilic bromination at the para-position of the polymer aromatic ring and subsequent Suzuki,Miyaura cross-coupling reactions with functionalized phenylboronic acids. The concentration of brominated styrene repeating unit in sPS was conveniently controlled by changing the ratio of added bromine relative to the polymer repeating unit. Brominated sPS (8.5 mol %) was converted quantitatively to other polar functional groups via Suzuki,Miyaura cross-coupling reactions with various functional group-substituted phenylboronic acids. The surface properties of functionalized sPS were studied by measuring water contact angles. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4335,4343, 2010 [source] Synthesis of new amphiphilic diblock copolymers containing poly(ethylene oxide) and poly(,-olefin)JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 20 2002Yingying Lu Abstract This article discusses an effective route to prepare amphiphilic diblock copolymers containing a poly(ethylene oxide) block and a polyolefin block that includes semicrystalline thermoplastics, such as polyethylene and syndiotactic polystyrene (s-PS), and elastomers, such as poly(ethylene- co -1-octene) and poly(ethylene- co -styrene) random copolymers. The broad choice of polyolefin blocks provides the amphiphilic copolymers with a wide range of thermal properties from high melting temperature ,270 °C to low glass-transition temperature ,,60 °C. The chemistry involves two reaction steps, including the preparation of a borane group-terminated polyolefin by the combination of a metallocene catalyst and a borane chain-transfer agent as well as the interconversion of a borane terminal group to an anionic (O,K+) terminal group for the subsequent ring-opening polymerization of ethylene oxide. The overall reaction process resembles a transformation from the metallocene polymerization of ,-olefins to the ring-opening polymerization of ethylene oxide. The well-defined reaction mechanisms in both steps provide the diblock copolymer with controlled molecular structure in terms of composition, molecular weight, moderate molecular weight distribution (Mw/Mn < 2.5), and absence of homopolymer. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3416,3425, 2002 [source] Miscibility in Blends of Isotactic/Syndiotactic Polystyrenes at Melt or Quenched Amorphous Solid StateMACROMOLECULAR MATERIALS & ENGINEERING, Issue 11 2006Shu Hsien Li Abstract Summary: Miscibility in amorphous phase and behavior in a crystalline phase of blends of two semicrystalline and isomeric polymers, isotactic polystyrene (iPS) and syndiotactic polystyrene (sPS), was probed. Optical and scanning electron microscopy results indicate no discernible heterogeneity in iPS/sPS blends in either melt state or rapidly quenched amorphous super-cooled state, while the Tg behavior of the quenched amorphous blends shows an intimately mixed state of two polymer chains. The crystal forms of the blends were further analyzed to provide additional evidence of miscibility in the amorphous domain. The sPS in the iPS/sPS blends upon melt crystallization was found to predominantly exist as the more stable , -form (rather than mixed , -form and , -form in neat sPS), which also suggests evidence of miscibility in the iPS/sPS blends. The melting behavior of semicrystalline sPS in the iPS/sPS mixtures was analyzed using the Flory-Huggins approach for estimation of interactions. By measuring the equilibrium melting point of the higher-melting sPS species in the sPS/iPS blends, a small negative value, for the interaction parameter (,,,,,0.11) was found. Further, by introducing a third polymer, poly(2,6-dimethyl- p -phenylene oxide) (PPO), a ternary iPS/sPS/PPO blend system was also proven miscible, which constituted a further test for stable phase miscibility in the iPS/sPS blend. General nature of miscibility in blends composed of two crystalline isomeric polymers is discussed. Issues in dealing with blends of polymers of the same chemical repeat unit but different tacticities were addressed. X-ray diffractograms for neat sPS and iPS/sPS blends, each having been isothermally crystallized at 245,°C for 4 h. [source] Selective Guest Uptake from Solvent Mixtures in the Clathrate Phase of Syndiotactic PolystyreneMACROMOLECULAR RAPID COMMUNICATIONS, Issue 22 2004Yukihiro Uda Abstract Summary: Selective absorption uptake during the guest-exchange processes in the , form of syndiotactic polystyrene (sPS) was confirmed by IR spectroscopy. When films of the , form were immersed in hexane/decane or chloroform/decane mixtures, decane molecules were incorporated preferentially in the , form. Sorbate uptake by the , form was greatly accelerated when the sorbate was mixed with a solvent penetrable to the amorphous region of sPS. Concentration changes in a , -form film during sorption processes: sorption of a chloroform(D)/decane(H) mixture (1:1 molar ratio). [source] Thermally-Induced Phase Transitions in the Uniaxially-Oriented , Form of Syndiotactic PolystyreneMACROMOLECULAR SYMPOSIA, Issue 1 2006E. Bhoje Gowd Abstract The empty , (,e) form of uniaxially-oriented syndiotactic polystyrene (sPS) samples were obtained by extracting the solvent molecules from the , form of sPS and solvent complex in acetone and methanol. Temperature dependence of the X-ray fiber diagrams starting from the uniaxially-oriented ,e and , form has been measured successfully at various temperatures for the first time. The transition behavior was traced clearly by separating the equatorial and layer line reflections. The ,e form transformed to the , form via an intermediate form. The intermediate form is speculated to take disordered structure due to the empty cavities present in the ,e form. Calorimetric studies showed an endotherm followed by an exotherm during this phase transition, which is consistant with such a speculation. On the other hand the , form transformed to the , form directly without passing through the intermediate form or ,e form. During the , to , phase transition the solvent molecules evaporate through the columnar structure in a broad range of temperature, allowing the transition to occur smoothly. [source] Reactive processing of syndiotactic polystyrene with an epoxy/amine solvent systemMACROMOLECULAR SYMPOSIA, Issue 1 2003Jaap Schut Abstract Syndiotactic polystyrene (sPS) is a new semi-crystalline thermoplastic which is believed to fill the price-performance gap between engineering and commodity plastics. In order to reduce the high processing temperature of sPS (>290°C), an epoxy-amine model system was used as a reactive solvent. Such a processing aid can be used to achieve a 50 to 500 fold lowering of the melt viscosity. When initially homogeneous solutions of sPS in a stoechiometric epoxy-amine mixture are thermally cured, Reaction Induced Phase Separation (RIPS) takes place, leading to phase separated thermoplastic-thermoset polymer blends. We focus our study on low (wt% sPS < 20%) and high concentration blends (wt% sPS > 60%) prepared by two processing techniques (mechanical stirring in a laboratory reactor or internal mixer/ reactive extrusion respectively). These blends have different potential interests. Low concentration blends (sPS domains in an epoxy-amine matrix) are prepared to create new, tunable blend morphologies by choosing the nature of the phase separation process, i.e. either crystallisation followed by polymerization or polymerization followed crystallisation. High concentration blends (sPS matrix containing dispersed epoxy-amine particles after RIPS) are prepared to facilitate the extrusion of sPS. In this case, the epoxy amine model system served as a reactive solvent. The time to the onset of RIPS is in the order of 7-9 min for low concentration blends, while it increases to 20-45 min for high concentration samples, as the reaction rates are substantially slowed down due to lower epoxy and amine concentrations. During the curing reaction the melting temperature of sPS in the reactive solvent mixture evolves back from a depressed value to the level of pure sPS. This indicates a change in the composition of the sPS phase, caused by (complete) phase separation upon reaction. We conclude that our epoxy amine system is suited for reactive processing of sPS, where final properties depend strongly on composition and processing conditions. [source] DGEBA monomer as a solvent for syndiotactic polystyreneMACROMOLECULAR SYMPOSIA, Issue 1 2003Jaap Schut Abstract Syndiotactic polystyrene (sPS) has to be processed at high temperatures (i.e. >290°C due to its melting point of 270°C), which approaches its degradation temperature. We aim to facilitate the processing of sPS by lowering its melt temperature and viscosity with a curable epoxy/amine model system as reactive solvent, which will result in a thermoplastic-thermoset polymer blend. As a first step we therefore investigated the melting behaviour of sPS in epoxy monomer, established its phase diagram, and investigated the crystalline form of sPS in these mixtures. DGEBA epoxy monomer is found to be a solvent for syndiotactic polystyrene at temperatures above 220°C. The DGEBA-sPS phase diagram was established by means of DSC, on the basis of crystallization and melting peaks. The form of the curve in the phase diagram indicates that DGEBA is a poor solvent for sPS. In WAXS studies of blends only the , crystalline form was detected, not the , form, thus no sPS-DGEBA polymer-solvent compounds (clathrates) were detected. However, DGEBA can still serve as a monomer for improved processing as it depresses the crystallization temperature by 20 to 60 K upon addition of 20 to 90 wt% DGEBA respectively, while a 16 to 45 K melting peak depression can be observed by adding 20 to 90 wt% DGEBA. [source] Preparation and characterization of pore wall-functionalized three-dimensionally ordered macroporous syndiotactic polystyrenePOLYMER ENGINEERING & SCIENCE, Issue 2 2009Xu Zhang A versatile method for the modification of three-dimensionally ordered macroporous (3DOM) highly syndiotactic polystyrene via chloromethylation at the pore walls has been demonstrated. This was followed by reaction with dimethylamine to establish a versatile approach to functionalization of such macroporous polymers. High syndiotacticity of 3DOM sPS is necessary for maintenance of the morphology of the original ordered pore structure after chloromethylation. The relative content of chloromethyl groups was shown to be 1.89 mmol/g3DOM sPS by TG-titration. The functionalized 3DOM sPS was characterized by SEM, FT-IR, and DSC to demonstrate that chloromethylation had occurred at the pore walls and that the dimethylamino moiety had replaced the chlorine atom of the chloromethyl group. DSC examination of the modified polymer indicated that the crystallinity of 3DOM sPS is little affected by functionalization. Thus the excellent properties of sPS are retained by the functionalized material. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers [source] A micromechanical model for the elastic properties of semicrystalline thermoplastic polymersPOLYMER ENGINEERING & SCIENCE, Issue 3 2004X. Guan This paper presents a micromechanical analysis of the elastic properties of semicrystalline thermoplastic materials. A lamellar stack aggregate model reported in the literature is used to derive tighter bounds and a self-consistent scheme for the elastic modulus, and it is shown that the existing geometric models of the microstructures are not effective in predicting experimentally measured modulus of semicrystalline materials. Toward addressing this limitation, a model based on Mori-Tanaka's mean field theory is developed by treating the semicrystalline materials as short-fiber reinforced composites, in which the lamella crystalline phase is modeled as randomly embedded anisotropic ellipsoidal inclusions, and the amorphous phase as an isotropic matrix. The lamellae are characterized by two independent aspect ratios from three distinct geometric axes in general. Existing morphological studies on polyethylene (PE) and a syndiotactic polystyrene (sPS) are used to deduce the corresponding lamella aspect ratios, based on which the theoretical model is applied to predict the elastic modulus of the two material systems. The model predictions are shown to compare well with the reported measurements on the elastic moduli of PE and sPS. Polym. Eng. Sci. 44:433,451, 2004. © 2004 Society of Plastics Engineers. [source] Styrene/substituted styrene copolymerization by Ph2Zn,metallocene,MAO systems: homo- and copolymerization of p -methoxystyrene with styrene,POLYMER INTERNATIONAL, Issue 5 2008Franco M Rabagliati Abstract BACKGROUND: The present work is part of a general study regarding the homo- and copolymerization of styrene using diphenylzinc,additive initiator systems, with the aim of improving the properties of commercial atactic polystyrene. The study is focused on syndiotactic polystyrene and/or copolymers of styrene (S) with substituted styrene, styrene derivatives or various ,-olefins. This research has been ongoing over the last 15 years. RESULTS: The reported experiments show that binary metallocene,methylaluminoxane (MAO) and ternary Ph2Zn,metallocene,MAO, depending on the metallocene employed, are capable of inducing both homo- and copolymerization of styrene and p -methoxystyrene (p -MeOS). The results indicate that for a styrene/p -MeOS mole ratio with p -MeOS > 25% the product obtained has only a minor incorporation of styrene units. The efficiency of the metallocenes studied follows the order bis(n -butylcyclopentadienyl)titanium dichloride ((n -BuCp)2TiCl2) > indenyltitanium trichloride (IndTiCl3) > Cp2TiCl2. CONCLUSION: Metallocenes (n -BuCp)2TiCl2, Cp2TiCl2 and IndTiCl3 in binary systems combined with MAO, as well as in ternary systems combined with Ph2Zn and MAO, induce the homopolymerization of p -MeOS and its copolymerization with styrene. The styrene/p -MeOS copolymer obtained was enriched in p -MeOS with respect to the initial feed, in agreement with the I+ inductive effect of the methoxy group in the para position of styrene. As already reported, the role of Ph2Zn was nullified by its complexation with the p -MeOS comonomer. Copyright © 2008 Society of Chemical Industry [source] Syndiotactic polystyrene: Process and applicationsADVANCES IN POLYMER TECHNOLOGY, Issue 3 2006Jürgen Schellenberg Abstract In this review, a summary is provided of the manufacturing process for syndiotactic polystyrene together with an overview of applications of syndiotactic polystyrenes, including selected examples of typical applications. The manufacturing process of syndiotactic polystyrene, consists of several basic sections: catalyst premix preparation, monomer treatment, polymerization reaction using a powder bed reactor together with an evaporative cooling system, devolatilization and extrusion, and finally finishing, including cooling and crystallization of the strands. This process is suitable for providing a wide range of syndiotactic polystyrenes comprising homopolymers, with a broad range of melt flow rates as well as copolymers of various comonomer contents, leading to products with various melting temperatures. Essential relationships and correlations of the separate process stages are demonstrated, in addition to useful analytical methods to control the process. These polymers' unique combination of heat resistance, chemical resistance, and electrical properties has led to their successful application in automotive, electrical and electronics, consumer and industrial uses. © 2006 Wiley Periodicals, Inc. Adv Polym Techn 25:141,151, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20069 [source] | |||||||||||||