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Showing papers on "Polymer blend published in 1984"


Journal ArticleDOI
01 Apr 1984-Polymer
TL;DR: In this article, it was shown that for a net exothermic mixing the individual interaction parameters for the pairs of units must differ from those predicted by solubility parameter theory.

470 citations


BookDOI
01 Jan 1984
TL;DR: Muggins et al. as discussed by the authors presented the Division of polymer chemistry award to Maurice L Muggins for the Structures of Collagen and discussed the effects of exposure of blood coagulation factors and platelets to synthetic polymers.
Abstract: Ceremony for the Presentation of the Division of Polymer Chemistry Award to Maurice L Muggins- The Structures of Collagen- Panel Discussion with Dr Muggins- Head to Mead Polymers- Polycondensation Reactions in the Presence of Polymer Matrices- Telechelic Polyethylene- Soluble Ladder Type of Poly(silesquioxanes) Maving Functional Groups- New Phosphorus-Containing Bisimide Resins- Crosslinking of Gelatin by Reactive Polymers Effect of Polymer Structure on Gelation Time- Study of Dextran-Methyl Methacrylate Graft Copolymer- The Kinetics and Mechanisms of the Dehydrohalogenation of the Poly(vinyl halides), PVC, PVDC and PVF- 1H NMR Studies on Conformation of Poly(vinylidene Fluoride) in Solution and Its Relation with Crystal Modification- Syntheses of Polymeric Azo Dyes of Pyrazolone Series- New Oligomeric Flame Retardants Containing s-Triazine Ring- Functional Effects of Exposure of Blood Coagulation Factors and Platelets to Synthetic Polymers- Analysis of Dielectric ?-Relaxation in Poly(methyl Acrylate) and Poly(t-butyl Acrylate)- Effects of Poisson's Ratio and Electrostriction Constant on Piezoelectricity in Poly(vinylidene Fluoride)- Influence of Shearing Histories on the Rheological Properties and Processability of Branched Polymers- Effects of Molecular Weight on the Aggregation of Poly(?-benzyl L-Glutamate in Dilute Solution- The Conformational Order in Hexadecane Solutions and Polyethylene- Entanglement Networks of 1,2-Polybutadiene Cross-linked in States of Strain: XV Simple Extension Special Case Comparison of the CKF Theory to Swelling Equilibrium Data- Electrophilic Olefins Containing Anionic Leaving Groups as New Cationic Initiators- Synthesis and Properties of Some Polymers Related to Biological Functions: Metal Transport and Template-directed Oligonucleotide Synthesis- Copolymerization of Carbon Dioxide and Epoxide and Related Reactions- Interactions Between Blood and Foreign Surfaces of Synthetic Polymers-Especially in Vascular Prothesis- Anionic Polymerization of p-Styrenyl Substituted Derivatives of Silicon, Germanium and Tin- Rare Earth Metal Containing Polymers: Energy Transfer Uranyl to Europium Ions in lonomers- Extration of Uranium from Sea Water by Synthetic Polymer Adsorbent- Selective Synthesis of Macrocyclic Oligoesters from a Bicyclic Oxalactone and Cation Transport through their Organic Liquid Membranes- The Efficiency of Glow Discharge Polymerization in Tubular Reactors- Interpolymer Association of Exciplex Forming Polymers under Extremely Dilute Conditions- Surface Modification of Aromatic Polyamides by Microwave Plasma Treatment- Modification of Polymer Surfaces by Surface Active Graftcopolymers- The Triplet State of Polymers with Pendent Aromatic Chromophores- Radiation-Induced Ionic Polymerization- Hydration of Poly(ethylenimine) Structures of Sesquihydrate (-Ch2Ch2Nh--l5H20)n and Dihydrate (-Ch2Ch2NH--2H20)n- Quantum Chemistry of Gauche-Oxygen Effect Observed in Polyethers- Transients in the Structure and Stress of Entangled Polymers Subjected to Step Changes in Shear Rate- New Emulsion System - Polymeric "Water in Water" Emulsion- Peel Behavior of Pressure-Sensitive Adhesives- Modeling the Viscoelastic Behavior of SBS Block Copolymer Solids- Physical Aging and Its Long-term Effect on the Durability and Reliability of Advanced Structural Epoxies and Epoxy-based Graphite-fiber Composites- On the Effect of Thermal Stability of Electron Donor, AIR3 Complex for the Property of High Active Supported Catalyst for PP- Membrane Separation and Its Industrial Applications- Structure and Properties of Polypeptide Block Copolymer Membranes- Structure and Properties of Poly(amino Acid) Solids- Specific Multi-layer Structure Polymer Composition- Strong Piezoelectric Activity in Simultaneously Streched and Poled Poly(vinylidene Flouride)- Vinylidene Fluoride-Hexafluoropropylene Copolymer Having Terminal Iodines- Hydrophilic Polyamide Membrane Prepared from Optically Active Bicyclic Oxalactam- Interfacial Tension of Demixed Polymer Solutions near Critical Solution Temperature- Fourier Transform-Infrared Studies of Polymer Blends: IV Poly(?-caprolactone)-Poly(Bis-phenol A-Carbonate) System- Crystal-Liquid Crystal Phase Transformation of Synthetic Bimolecular Membranes- Non-Equilibrium Processes in Stressed Polymeric Glasses- Energy and Electron Transfer in Mi cellar and Polymeric Systems: Kinetic Mimicry of Chlorophyll- Microstructure and Piezoelectricity in Poly(vinylidene Fluoride) Films- Stripping Rate of Residual Styrene Monomer from Latexes of Polystyrene and SBR- Characterization of Thermal and Optical Properties of Polymers by Thermal Lensing Technique- Fraction of Polymers by U1trafiltration: A Computer Simulation Study- Entanglement Networks of 1,2-Polybutadiene Cross- Linked in States of Strain XV Simple Extension Case: Application of the CKF Theory to Stress Strain and Stress Relaxation Data- Poly(aryl Ether)-Poly(arylate) Block Copolymers: I Polysulfone-Bis-A Terephthalate Systems- Stress-Related Surface Tension Effects in Hard Elastic Polymers

411 citations


Journal ArticleDOI
Ezio Martuscelli1
TL;DR: In this paper, an investigation on the morphology, the crystallization and the thermal behavior of several binary crystallizable blends are reported, and it was found that the addition of a second non-crystallizable component causes drastic variations on some morphological and structural quantities of the semicrystalline matrix (isotactic polypropylene or nylon 6).
Abstract: Results of an investigation on the morphology, the crystallization and the thermal behavior of several binary crystallizable blends are reported. The composition, molecular mass and crystallization conditions strongly influence the crystallization and the thermal behavior as well as the overall morphology of crystallizable binary blends. Quantities such as nucleation density (N), radial growth rate (G) of spherulites, overall rate of crystallization (K), and equilibrium melting temperature (Tm) are strongly dependent upon composition, crystallization conditions, and molecular mass of components. The type of dependence is to be related to the physical state of the melt, which, at the crystallization temperature, is in equilibrium with or coexists with the developing solid phase. In the ease of compatible blends such as poly(ethylene oxide)/poly(methyl methacrylate) the depression observed for G and Tm is mainly to be attributed to the diluent effect of the non-crystallizable component. For such a blend it is found that, after crystallization, the non-crystallizable component is trapped in intralamellar regions increasing the distance between adjacent lamellae. Depression of G, in the case of incompatible blends such as isotactic polypropylene/rubbers is mainly accounted for by rejection and deformation of rubber drops. The coexistence during crystallization of different processes such as molecular fractionation and segregation, preferential inclusion or dissolution of molecules with lower molecular mass and/or high degree of steric disorder of the crystallizable component in the phase rich in non-crystallizable component and vice versa may explain some minima observed in the plots of T and Tm, vs. composition in the case of blends semicompatible in the melt. It was found that the addition of a second non-crystallizable component causes drastic variations on some morphological and structural quantities of the semicrystalline matrix (isotactic polypropylene or nylon 6) such as the shape, dimensions, and regularity of spherulites and interspherulite boundary regions and lamella and interlamella thickness. In some cases the formation of new boundary lines connecting occluded particles are also observed. Such phenomena may have great importance on crack propagation and on impact behavior as well as on the tensile mechanical properties of binary blends characterized by a semicrystalline polymer component with a relatively high Tg and a rubber-like component with a lower Tg.

194 citations


Journal ArticleDOI
TL;DR: In this paper, the stability and oscillatory shearing flow properties of compatible and incompatible polymer blend systems were measured using a cone-and-plate rheometer and photomicrographs describing the state of dispersion.
Abstract: Steady and oscillatory shearing flow properties of compatible and incompatible polymer blend systems were measured, using a cone-and-plate rheometer. The compatible blend systems investigated are blends of two low-density polyethylenes (LDPE) having different values of molecular weight and blends of poly(methyl methacrylate) (PMMA) with poly(vinylidene fluoride) (PVDF). The incompatible blend system investigated is a blend of poly(methyl methacrylate) (PMMA) with polystyrene (PS). It was found that (1) plots of first normal stress difference (τ11 – τ22) vs. shear stress (τ12) and plots of storage modulus (G′) vs. loss modulus (G″) for the LDPE blends become independent of temperature and blend composition; (2) plots of τ11 – τ22 vs. τ12, and G′ vs. G″ for the PMMA/PVDF blends become independent of temperature but dependent upon blend composition. It was found further that, for the incompatible PMMA/PS blends, the dependence of τ11 – τ22 on blend composition, when plotted against τ12, is different from the dependence of G′ on blend composition, when plotted against G″. However, in both compatible and incompatible blend systems, plots of τ11 – τ22 vs. τ12 and plots of G′ versus G″ are independent of temperature. The seemingly complicated composition-dependent rheological behavior of the incompatible blend system is explained with the aid of photomicrographs describing the state of dispersion.

189 citations


Journal ArticleDOI
TL;DR: In this paper, the FT-IR de melanges de polyvinylphenol avec lacetate polyvinylonique and l'EVA was used. Influence de la temperature
Abstract: Resultats FT-IR de melanges de polyvinylphenol avec l'acetate polyvinylique et l'EVA. Influence de la temperature

173 citations


Journal ArticleDOI
TL;DR: Polymer blends are analogous to metal alloys, materials which date back to the dawn of civilization as mentioned in this paper and have been used to improve the chemical and physical properties of metallic materials by mixing various metals, and polymer scientists have also employed this technique to produce a wide variety of useful polymeric materials.
Abstract: Polymer blends may be defined a s physical mixtures of two or more polymers [1]. Conceptually, polymer blends are analogous to metal alloys, materials which date back to the dawn of civilization. In much the same way as the metallurgists sought to improve the chemical and physical properties of metallic materials by mixing various metals, polymer scientists have also employed this technique to produce a wide variety of useful polymeric materials. However, we must be careful not to push this analogy too far. There are many fundamental differences between these two classes of materials.

161 citations


Journal ArticleDOI
01 Feb 1984-Polymer
TL;DR: In this paper, a morphological study of polypropylene/ethylene-propylene-diene terpolymer (PP/EPDM) and polyethylene/polyolefin thermoplastic rubber blends was conducted.

159 citations


Book ChapterDOI
01 Jan 1984
TL;DR: In many cases, this can be done more simply, more effectively, and less expensively by mixing the original polymer with other materials, such as a gas, a low-molar-mass liquid, a plastic, or another solid material as mentioned in this paper.
Abstract: Chemical modification is not the only means of changing the properties of a polymer. In many cases, this can be done more simply, more effectively, and less expensively by mixing the polymer with other materials. The new properties produced depend on the nature and physical state of the original polymer, on the nature, physical state, and means of processing in the added material, on the mixing ratio of the original polymer to added material, on the interaction between the components, as well as on the processing steps to which they are then subjected. The original polymer may be a thermoplast, a thermoset, an elastoplast, or an elastomer. The additive may be a gas, a low-molar-mass liquid, a plastic, or another solid material. The added material may be present three dimensionally as a network, two dimensionally as a fabric, one dimensionally as a fiber, or “zero dimensionally” as powder or flakes. The resulting mixture may be single or multiphased.

152 citations



Journal ArticleDOI
TL;DR: Application de cette technique d'un melange homogene chitosane-alcool polyvinylique afin d'elucider les mecanismes moleculaires impliques dans ses proprietes mecaniques.
Abstract: Application de cette technique d'un melange homogene chitosane-alcool polyvinylique afin d'elucider les mecanismes moleculaires impliques dans ses proprietes mecaniques

133 citations


Journal ArticleDOI
TL;DR: The use of polymeric compatibilization additives to polymer blends has shown promise as a method to improve mechanical compatibility in phase-separated blends, and will be expected to be the subject of future research programs as discussed by the authors.
Abstract: In the past decade, polymer blend technology has achieved an important position in the field of polymer science. With increased academic and industrial research interest, the application of polymer blend technology to commercial utility has grown significantly. This review on the applications of polymer blends will cover the major commercial blends in the categories of styrene-based polymer blends, poly(vinyl chloride) blends, polyacrylate blends, polyester and polycarbonate blends, polyolefin blends, elastomer blends, polyelectrolyte complexes, and interpenetrating polymer networks. New developments in polymer blend applications will be discussed in more detail. These systems include linear low-density polyethylene blends with either low- or high-density polyethylene, styrenemaleic anhydride terpolymer/ABS (acrylonitrile-butadiene-styrene) blends, polycarbonate/poly(butylene tetephthalate) blends, new PPO/polystyrene blends, and tetramethyl bisphenol A polycarbonate/impact polystyrene blends. Areas for future research to enhance the potential for polymer blend applications will be presented. The need for improved methods for predicting miscibility in polymer blends is discussed. Weldline strength is a major property deficiency of two-phase systems (even those with mechanical compatibility), and future research effort appears warranted to resolve this deficiency. The use of polymeric compatibilization additives to polymer blends has shown promise as a method to improve mechanical compatibility in phase-separated blends, and will be expected to be the subject of future research programs. Finally, the reuse of polymer scrap is discussed as a future application area for polymer blends. Unique applications recently proposed for polymer blends include immobilization of enzymes, permselective membranes, reverse osmosis membranes, selective ion-exchange systems, and medical applications using polyelectrolyte complexes.

Journal ArticleDOI
TL;DR: In this paper, lower critical solution temperature (LCST) behavior in polymer blends is shown to be the result of the compressible nature of the system, the directional-specific character of the intermolecular interactions, or a combination of both.
Abstract: Lower critical solution temperature (LCST) behavior in polymer blends is shown to be the result of the compressible nature of the system, the directional-specific character of the intermolecular interactions, or a combination of both. Certain random copolymer-homopolymer blends are examples of the first possibility. To illustrate the possibility of LCST behavior due to the directional-specific character of the intermolecular interactions, a recently introduced incompressible lattice-gas model by Vause and Walker is adapted to the polymer problem. Homopolymers are shown to be miscible if there is an acid-base interaction of sufficient strength and if the difference between the respective solubility parameters is not too large. The amount of entropy lost in the formation of a specific interaction is shown to be an additional important factor in determining polymer miscibility. Specific heat measurements can, in principle, decide whether the behavior of a polymer mixture at a given temperature is dominated by its compressibility or by the directional-specific interactions.

Journal ArticleDOI
TL;DR: In this paper, mixing rules which relate gas permeation in homogeneous multicomponent polymer materials to that in pure component polymers have been developed from both the activated state and free volume theories of transport.

Patent
Saleh A. Jabarin1
16 Jul 1984
TL;DR: In this paper, a polyester based intimate fusion blended composition comprising an admixture of a poly(ethylene terephthalate) and a copolyester of isophthalic and terphthalic acid, ethylene glycol and 1,3 bis(2-hydroxyethoxy)benzene is disclosed.
Abstract: A polyester based intimate fusion blended composition comprising an admixture of a poly(ethylene terephthalate) and a copolyester of isophthalic and terephthalic acid, ethylene glycol and 1,3 bis(2-hydroxyethoxy)benzene is disclosed. The novel material disclosed is suitable for fabrication into container parison, hollow containers, sheet stock and film. Such articles exhibit excellent gas barrier properties, mechanical strength and processability.

Journal ArticleDOI
TL;DR: In this paper, the authors present a range of special and reinforced polypropylene grades, including elastomer-modified PP, elastomers modified filled PP, glass fiber-reinforced PP, filled PE, esthetic PE, flame-retardant PP, and thermoplastic PE.
Abstract: The new industrial strategy in the polymer field requires the transformation of plastic “commodities” into “specialties”. From this point of view, polypropylene (PP) plays an important role both for its intrinsic properties such as high melting temperature, low density, high chemical inertness and for its capability to be produced with different morphological and molecular structures, to be modified with the addition of other polymers or mineral fillers and to be grafted with functional groups. The present range of special and reinforced polypropylene grades includes: elastomer-modified PP, elastomer-modified filled PP, glass fiber-reinforced PP, filled PP, esthetic filled PP, flame-retardant PP, and thermoplastic elastomers. New trends for significantly improving this family of polymers involve impact resistance, processability, durability, dimensional stability, elasticity, and surface properties. A positive answer to this complex emerging demand will put, as indicated, in this work, “special and reinforced polypropylene grades” in a position to successfully compete with technopolymers in some important, rapidly growing application sectors.


Patent
25 Jun 1984
TL;DR: In this article, a mixture of a high molecular weight polyethylene and a low molecular weight homopolymer with a narrow molecular weight distribution and low levels of long chain branching is presented.
Abstract: Ethylene polymer blends of a high molecular weight ethylene polymer, preferably an ethylene-mono-1-olefin copolymer, and a low molecular weight ethylene polymer preferably an ethylene homopolymer, both preferably with narrow molecular weight distribution and low levels of long chain branching exhibit excellent film properties and good environmental stress crack behavior superior to that expected for polyethylene of comparable density and melt flow. These resins are useful for the manufacture of film or in blow molding techniques, the production of pipes and wire coating.

Journal ArticleDOI
TL;DR: In this paper, the compatibility of polymer blends of poly(ϵ-caprolactone) (PCL) and poly(styrene-co-acrylonitrile) (SAN) containing various acrylonitic (AN) contents was studied to evaluate the influences of copolymer composition and PCL concentration upon blend compatibility.
Abstract: The compatibility of polymer blends of poly(ϵ-caprolactone) (PCL) and poly(styrene-co-acrylonitrile) (SAN) containing various acrylonitrile (AN) contents was studied to evaluate the influences of copolymer composition and PCL concentration upon blend compatibility. Blend compatibility was characterized by the occurence of a single glass transition intermediate between the transitions of the respective pure components. The glass transitions were determined by differential scanning calorimetry (DSC) and dynamic mechanical measurement (Rheovibron). It was found that SAN and PCL form compatible blends when the AN content of SAN ranges from 8% to 28% by weight. These blends are compatible in all proportions except for SAN 28 (AN wt % = 28) and PCL blends containing 70 or 85 wt % PCL. Blends of PCL and SAN were found to be incompatible when the AN content in SAN is greater than 30 wt % or less than 6 wt %. Lower critical solution temperature (LCST) behavior, which can be attributed to phase separation, was found to occur when these blends were heated to elevated temperatures. The cloud point, or phase separation, was found to vary with AN content in SAN and the concentration of SAN in the blend.

Patent
25 Apr 1984
TL;DR: A block copolymer consisting of a hydrophilic polymer portion and a polymer portion having a compatibility with a polymer material can be easily synthesized in the presence of a polymeric peroxide or a polyazo compound, and can modify easily and permanently the surface of the polymer material as discussed by the authors.
Abstract: A block copolymer consisting of a hydrophilic polymer portion and a polymer portion having a compatibility with a polymer material can be easily synthesized in the presence of a polymeric peroxide or a polyazo compound, and can modify easily and permanently the surface of the polymer material.

Patent
04 May 1984
TL;DR: A polymer composition comprising a polymer and an organic metal complex uniformly dispersed or dissolved therein is defined in this paper as a mixture of polymers and organic metal complexes that can be used to create polymers.
Abstract: A polymer composition comprising a polymer and an organic metal complex uniformly dispersed or dissolved therein.

Journal ArticleDOI
TL;DR: Etude par diffusion de la lumiere des melanges polystyrene-polybutadiene-toluene et poly styrene-copolymere bisequence (styrene)-butadienes)-toluanene as discussed by the authors.
Abstract: Etude par diffusion de la lumiere des melanges polystyrene-polybutadiene-toluene et polystyrene-copolymere bisequence (styrene-butadiene)-toluene

Journal ArticleDOI
TL;DR: In this paper, a multiple-celi apparatus for vapor-liquid equilibria measurements in concentrated polymer solutions is described, and experimental data on vapor-pressure lowering for four polymer polymers and one block copolymer-solvent system are reported.
Abstract: A new multiple-celi apparatus for vapor-liquid equilibria measurements in concentrated polymer solutions is described. Experimental data on vapor-pressure lowering for four polymer–polymer–solvent systems and one block copolymer–solvent system are reported. The Flory–Huggins χ interaction parameters for the corresponding polymer pairs are evaluated. For ternary systems, the results are expressed in terms of a parameter χ1,23 which reduces to the classical Flory–Huggins χ interaction parameter for the case of binary mixtures. Experimental data measured in this work are compared with existing literature data.

Patent
27 Sep 1984
TL;DR: In this article, the authors introduced the concept of polymers, which are produced through using organic acids, together with the products obtained therefrom and are insoluble in water, but soluble in an alkaline medium.
Abstract: The invention relates to polymers, which are produced through using organic acids, together with the products obtained therefrom. The polymers and the products obtained therefrom are insoluble in water, but soluble in an alkaline medium. There are numerous interesting possible uses for the polymers.

Patent
19 Oct 1984
TL;DR: A moisture vapor transmitting elastomeric film which comprises a blend of incompatible polymers and contains voids characterized in that the blend comprises a continuous matrix of ethylene vinyl acetate within which the incompatible polymer forms a discrete particulate phase matrix, processes for the preparation thereof and articles comprising these films are described as mentioned in this paper.
Abstract: A moisture vapor transmitting elastomeric film which comprises a blend of incompatible polymers and contains voids characterized in that the blend comprises a continuous matrix of ethylene vinyl acetate within which the incompatible polymer forms a discrete particulate phase matrix, processes for the preparation thereof and articles comprising these films are described.

Journal ArticleDOI
TL;DR: In this paper, a differential scanning calorimetry was used to investigate polymethacrylate/chlorinated polymer blends, and they were found to be miscible with poly(vinyl chloride) (PVC), chlorinated PVC, and Saran, but not with a polyethylene containing 48% chlorine.
Abstract: Thirty-five polymethacrylate/chlorinated polymer blends were investigated by differential scanning calorimetry. Poly(ethyl), poly(n-propyl), poly(n-butyl), and poly(n-amyl methacrylate)s were found to be miscible with poly(vinyl chloride) (PVC), chlorinated PVC, and Saran, but immiscible with a chlorinated polyethylene containing 48% chlorine. Poly(methyl) (PMMA), poly(n-hexyl) (PHMA), and poly(n-lauryl methacrylate)s were found to be immiscible with the same chlorinated polymers, except the PMMA/PVC, PMMA/Saran, and PHMA/Saran blends, which were miscible. A high chlorine content of the chlorinated polymer and an optimum CH2/COO ratio of the polymethacrylate are required to obtain miscibility. However, poly(methyl), poly(ethyl), poly(n-butyl), and poly(n-octadecyl acrylate)s were found to be immiscible with the same chlorinated polymers, except with Saran, indicating a much greater miscibility of the polymethacrylates with the chlorinated polymers as compared with the polyacrylates.

Journal ArticleDOI
TL;DR: In this paper, a number of examples of helical polyolefins (polypropylene (PP) and poly(1-butene)) (PB-1) possess crystallographic faces in which the side-groups form well aligned rows.
Abstract: Helical polyolefins (polypropylene (PP) and poly(1-butene)) (PB-1) possess crystallographic faces in which the side-groups form well aligned rows. These structural features are shown, through a number of examples, to interact with linear polymers (polyethylene (PE) and polyamides) and nucleating agents. These interactions explain, on the basis of characteristic epitaxial relationships, the mutual activity of certain pairs of crystalline polymers and the hitherto puzzling “universality” of some nucleating agents towards both linear (i.e. PE-like) polymers and helical polyolefins.

Journal ArticleDOI
TL;DR: Small-angle neutron scattering, SANS, stands forth as one of the most important tools for evaluating polymer chain conformation and morphology as discussed by the authors, and has been widely used in the literature.
Abstract: Small-angle neutron scattering, SANS, stands forth as one of the most important of the new tools for evaluating polymer chain conformation and morphology This paper reviews the SANS literature through 1982, with a few early 1983 references added The theory of SANS is outlined and compared to light scattering SANS values of polymer molecular weights and radii of gyration obtained in the bulk state were found to be in agreement with values obtained from dilute solutions by light scattering In each case, deuterated fractions of polymer were inserted into the hydrogeneous matrix, or vice versa, to provide contrast Several new research areas are then discussed, including unidirectional stretching of elastomers, stress-relaxation, polymer-polymer miscibility, crystallization from the melt compared with crystallization from dilute solutions, nonclassical aggregation during bulk polymerization of thermoset systems, morphology of polymer blends, block copolymers and ionomers, the core-shell structure of latexes and polymer blocks, and grafts as surfactants in emulsions and latexes Much new and sometimes unexpected information is being provided by the SANS research now in progress

Journal ArticleDOI
TL;DR: In this paper, the composition and microstructure of a blend of bisphenol-A polycarbonate (PC) and poly (butylene terephthalate) (PBT) have been established by a variety of physical methods.
Abstract: The composition and microstructure of a blend of bisphenol-A polycarbonate (PC) and poly (butylene terephthalate) (PBT) have been established by a variety of physical methods. The composition was established by solvent extraction and infra-red spectrophotometry, while the microstructure was determined by these and the additional methods of differential scanning calorimetry and dynamic mechanical thermal analysis. The PBT retained its crystallinity in the commercial blend, (Xenoy CL-100), but blending reduced the main glass-rubber transition of the PC from 147°C to approximately 100°C. Conditioning of the blend at high temperatures resulted in progressive transesterification: 3 minutes at 240°C gave a small but significant effect, while 30 minutes at 270°C yielded large changes in the structure. These findings are important in respect of processing the material, and the limitations which might be incurred in plant recycling of scrap.

Journal ArticleDOI
01 Nov 1984-Polymer
TL;DR: In this paper, the synthesis and properties of a polyether urethane network based on Adiprene L-100, of poly(dimethylsiloxane) network and of nine interpenetrating polymer networks based on these polymers were investigated.

Journal ArticleDOI
TL;DR: In this article, a method for estimating the rheograms of polymer melts through the use of the melt flow index has been extended to polyblends, based on the altered free volume state model.
Abstract: Polymer blends have received a lot of attention in recent years due to the possibility of getting compounds with novel and/or different properties through proper marriage of the properties of the respective mono-components. The flow behaviour of blends when subjected to stresses is complex and is often found not to vary monotonically with composition. Mixing rules and mixture theories have been used for estimating melt viscosity of a blend at zero shear rate. However a knowledge of the entire rheogram is desirable for process optimization, process design and trouble shooting. In the present paper a method proposed earlier to estimate the rheograms of polymer melts through the use of the melt flow index has been extended to polyblends. A method for obtaining the melt flow index of the polymer blends at various compositions from the melt flow index of the individual components and the blend ratio has been suggested based on the altered free volume state model. Curves that are coalesced using the me...