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Showing papers on "Polymer published in 1985"


Book
01 Jan 1985
TL;DR: In this paper, the authors describe a chain transfer characterisation of polymers charge-transfer complexes, charge transfer complexes and charge transfer complexes of charge transfer and charge-Transfer complexes.
Abstract: Cellular Materials Cellulose Cellulose, Biosynthesis Cellulose, Graft Copolymers Cellulose, Microcrystalline Cellulose Derivatives Cellulose Esters, Inorganic Cellulose Esters, Organic Cellulose Ethers Cement Additives Chain-Reaction Polymerization Chain Transfer Characterization of Polymers Charge-Transfer Complexes Chelate- Forming Polymers Chemical Analysis Chemically Resistant Polymers Chitin Chloroprene Polymers Chlorotrifluorethylene Polymers Chromatography Classification of Polymerization Reactions Coating Methods Coatings Coatings, Electrodeposition Cold Forming.

7,256 citations



Journal ArticleDOI
TL;DR: Polyvinylpyrrolidone (PVP) has a high molecular weight distribution due to transfer reactions as discussed by the authors, and it has a very high glass transition temperature of about 175°C and falls to values under 100°C with decreasing molecular weight.
Abstract: Polyvinylpyrrolidone (PVP) having molecular weights (Mw) from 2500 to about 1 million is mainly obtained by radical polymerization in solution The higher molecular weight type products are polymerized in aqueous solution mostly using hydrogen peroxide as initiator The polymers thus obtained have hydroxyl and carbonyl end groups More stable end groups can be obtained by polymerization in solvents, which may act as chain transfer agents and which produce low molecular weight type products Copolymers especially with monomers such as vinyl acetate and with various acrylic compounds may also be produced by solution polymerization Popcorn polymerization leads to insoluble PVP Thereby VP is polymerized without initiator in the presence of small amounts of bifunctional monomers The polymeric flakes thus formed are highly cross-linked, mainly due to entanglements The molecular weight distribution of soluble PVP is broad due to transfer reactions An unusual property of PVP is its solubility in water as well as in various organic solvents The glass transition temperature of high molecular weight polymers (Mw=1 million) is about 175°C and falls to values under 100°C with decreasing molecular weight Mw=2500) PVP forms complexes with various compounds, especially with H-donors such as phenols and carboxylic acids The complex formed with cross-linked PVP and polyphenols is used commercially for the clarification of beverages Another commercial use is the complexation of iodine with linear PVP, which leads to effective disinfectants of very low toxicity Further important applications of PVP in the pharmaceutical field are their use as binding or film forming agents for tablets, and as solubilizing agents for injections The swelling ability of cross-linked PVP in water is used in disintegrating agents for tablets In the cosmetic field VP polymers are used as film formers for hair dressing products Examples of technical applications are adhesives, textile auxiliaries and dispersing agents

489 citations


Journal ArticleDOI
TL;DR: The acrylic acid polymer showed a longer GI transit time than the methacrylic acid polymer, and this in vivo GI transit result is consistent with in vitro bioadhesion test results.

486 citations


Journal ArticleDOI
TL;DR: In this article, a technique is described which uses differential scanning calorimetry to estimate the glass transition of polymers containing a dissolved gas, and the effects of CO2 sorption at pressures up to 25 atm were examined.
Abstract: A technique is described which uses differential scanning calorimetry to estimate the glass transition of polymers containing a dissolved gas. The technique is simple and appears to give reliable results. The effects of CO2 sorption at pressures up to 25 atm were examined in detail for poly(methyl methacrylate) and its blends with poly(vinylidene fluoride). Less extensive results for polystyrene, polycarbonate, poly(vinyl chloride), and poly(ethylene terephthalate) are also given. Reductions in Tg of up to 50°C are observed. A theoretical relation by Chow predicts results in reasonable agreement with the experimental data. These findings are relevant to various applications such as membrane separation processes for gases.

364 citations


Journal ArticleDOI
TL;DR: In a dispersion polymerization process, the reaction mixture starts out as a homogeneous solution and the resulting polymer precipitates as spherical particles, stabilized by a steric barrier of di....
Abstract: In a dispersion polymerization process, the reaction mixture starts out as a homogeneous solution and the resulting polymer precipitates as spherical particles, stabilized by a steric barrier of di...

314 citations


BookDOI
01 Jan 1985
TL;DR: Theoretical basis for liquid crystallinity in polymers has been discussed in this article, where the authors describe synthesis, structure, properties, and properties relations between polymers and their properties.
Abstract: I: Synthesis, Structure, Properties Relationships.- 1. Synthetic Routes to Liquid Crystalline Polymers.- 2. Chiral Thermotropic Liquid Crystal Polymers.- 3. Solid State Physics of Thermotropic Polyesters: Internal Friction of Mesomorphic Structures.- 4. Thermotropic Liquid Crystal Aromatic Copolyesters Containing Cycloaliphatic Units.- 5. Polymerization of Allyldimethyldodecylammonium Bromide Liquid Crystalline Monomer to Its Liquid Crystalline Polymer.- II: Theory.- 6. Theoretical Basis for Liquid Crystallinity in Polymers.- 7. Nematic Liquid Crystals Formed from Flexible Molecules: a Molecular Field Theory.- 8. Order and Odd-Even Effects in Thermotropic Nematic Polyesters.- III: Characterization.- 9. Structure and Characterization of Thermotropic Liquid Crystalline Polymers.- 10. Observations on the Rheology of Thermotropic Polymer Liquid Crystals.- 11. Rheo-Optical Studies of the Thermotropic Aromatic Copolyesters of Poly(Ethylene Terephthalate) and p-Acetoxybenzoic Acid.- 12. Electron Microscopy of Thermotropic Copolyesters.- 13. Nuclear Spin-Label Studies of Liquid Crystal Polymers.- 14. Viscosity and the Thermodynamic Properties of Liquid Crystalline Polymers with Mesogenic Side Groups.- 15. Measurement of Orientational Order in Liquid Crystalline Samples by NMR Spectroscopy.- 16. Phase Behaviour of Dye-Containing Liquid Crystalline Copolymers and Their Mixtures with Low Molecular Weight Liquid Crystals.- 17. Dielectric Relaxation Measurements and X-ray Investigations of Liquid Crystalline Side-Chain Polymers.- 18. Structural Investigations on Liquid Crystalline Side-Chain Polymers.- 19. Macromolecular Order and Conformation in the Solid and Nematic Phases of Semi-Rigid Polymers and Polymer-Monomer Mixtures-NMR Study.- IV: Applications.- 20. Aramids-Bridging the Gap between Ductile and Brittle Reinforcing Fibres.- 21. Towards a Photoconductive Liquid Crystal: Carbazole-Containing Systems.- 22. Electro-Optic Effects in a Smectogenic Polysiloxane Side-Chain Liquid Crystal Polymer.

268 citations


Patent
13 Jul 1985
TL;DR: In this paper, improved hydrogel-forming polymer compositions which can be used as absorbents in absorbent structures and absorbent articles such as diapers, sanitary napkins and the like are presented.
Abstract: The present invention relates to improved hydrogel-forming polymer compositions which can be used as absorbents in absorbent structures and absorbent articles such as diapers, sanitary napkins and the like. Such hydrogel-forming polymer compositions are substantially water-insoluble, slightly cross-linked, partially neutralized polymers which are prepared from unsaturated polymerizable, acid group-containing monomers and cross-linking agents. These hydrogel-forming polymer materials, upon imbibing fluids, form hydrogels. Such polymer materials have relatively high gel volume and relatively high gel strength as measured by shear modulus of the hydrogel which forms therefrom. Such polymer materials also contain relatively low levels of extractable polymer material which can be extracted therefrom by contact with synthetic urine. Preferred hydrogel-forming polymers having these characteristics can be prepared by polymerizing the acid group-containing monomers in their free acid form at relatively low monomer concentrations, preferably using relatively low polymerization temperatures. Absorbent structures and absorbent articles containing these dried hydrogel-forming polymer materials are also disclosed.

262 citations


Journal ArticleDOI
TL;DR: In this article, structural features of the adhesive polymer were explored using a copolymer of acrylic and methacrylic acid with variation in charge density and hydrophobicity of the molecules.

256 citations


Journal ArticleDOI
Magnus Glad1, Olof Norrlöw1, Börje Sellergren1, Nils Siegbahn1, Klaus Mosbach1 
TL;DR: The use of organic silane monomers in the preparation of substrate-selective polymers by molecular imprinting is described in this article, where polysiloxane copolymers imprinted with the dyes rhodanile blue or safranine O showed preferential binding of the respective compound.

243 citations


MonographDOI
25 Sep 1985

Journal ArticleDOI
TL;DR: In this paper, a new technique of decorating the fold surface of polymer crystals is described, similar in methodology to gold decoration, but makes use of vapors of crystallizable polymers, principally polyethylene, as decorating material.
Abstract: A new technique of decoration of the fold surface of polymer crystals is described. It is similar in methodology to gold decoration, but makes use of vapors of crystallizable polymers, principally polyethylene, as decorating material. Upon condensation and crystallization, the highly anisometric decorating molecules become oriented parallel to the fold direction. They build up small crystalline lamellae which, seen edge-on, appear as elongated rods and can be easily observed by conventional transmission electron microscopy. This decoration technique reveals the sectorization of polymer single crystals grown from solution. It can be used to determine the local fold orientation (with a resolution of ca. 10 nm) of polymers crystallized under a wide range of conditions, including crystallization from the bulk. The technique reveals that under all crystallization conditions so far investigated the outermost part of the polymer fold surface is relatively ordered, and the folds and/or loops are, as a rule, oriented nearly parallel to the macroscopic growth front.

Journal ArticleDOI
TL;DR: In this article, bisphenol-A polysulfone (PSF) oligomers were used in the modification of Epon Resin 828/4,4′-diamino-diphenyl sulfone (DDS) network system.
Abstract: Functionally terminated bisphenol-A polysulfone oligomers were used in the modification of Epon Resin 828/4,4′-diamino-diphenylsulfone (DDS) network system. Phenolic hydroxyl terminated PSF oligomers were first capped with a large excess of bisphenol-A diglycidyl ether or Epon Resin 828 at both ends and then the resulting system was cured with DDS, in a two-step process. During these studies molecular weight and the amount of PSF oligomers incorporated into the network were varied and their effect on the overall properties of the resulting systems were investigated. The capping and curing reactions were followed by using FT-IR and NMR spectroscopy, GPC, HPLC and DSC techniques. As a function of the oligomer molecular weight, SEM studies showed the formation of two-phase structures with ductile PSF particles dispersed in the continuous epoxy matrix. Mechanical characterization and fracture toughness measurements showed a remarkable increase in KIC or gIC values of the modified networks over that of control, without significant loss in the modulus. This work would appear to be one of the first studies where well bonded ductile glassy modifiers have significantly improved the fracture toughness of highly crosslinked networks.

Patent
09 May 1985
TL;DR: In this paper, an admixture of water-soluble polycarboxylates and an unsaturated carboxylic acid was used to inhibit the formation of insoluble alluvial, metal oxide and metal hydroxide deposits in an aqueous system.
Abstract: The instant invention is directed to an admixture, and its use in inhibiting scale and corrosion in aqueous systems, comprising: (a) a water-soluble polymer having a weight average molecular weight of less than 25,000, as determined by low angle laser light scattering, comprising an unsaturated carboxylic acid and an unsaturated sulfonic acid, or their salts, having a ratio of 1:20 to 20:1, and (b) at least one compound selected from the group consisting of water-soluble polycarboxylates, phosphonates, phosphates, polyphosphates, metal salts and sulfonates. The instant invention is also directed to a method of inhibiting the formation of insoluble alluvial, metal oxide and metal hydroxide deposits in an aqueous system, comprising adding to the system at least 0.1 mg/l of a water-soluble polymer having a weight average molecular weight of less than 25,000, as determined by low angle laser light scattering, comprising an unsaturated carboxylic acid and an unsaturated sulfonic acid, or their salts, having a ratio of 1:20 to 20:1 and a phosphonate.

Journal ArticleDOI
TL;DR: In this article, the effects of various additives were examined to improve the room temperature ionic conductivity of poly(ethylene oxide) doped with lithium salts, and an optimized composition had a much improved conductivity, achieving 10−4 (Ω cm)−1 at 40 °C.

Patent
24 Oct 1985
TL;DR: In this paper, a method for the continuous production of a cross-linked polymer having a low proportion of large particles, comprising the steps of continuously feeding the aqueous solution of a monomer capable of being converted by aaqueous solution polymerization into a water-containing crosslinked gel polymer and a polymerization initiator to a vessel provided with a plurality of mutually parallel rotary stirring shafts each fitted with stirring blades, was described.
Abstract: A method for the continuous production of a cross-linked polymer having a low proportion of large particles, comprising the steps of continuously feeding the aqueous solution of a monomer capable of being converted by aqueous solution polymerization into a water-containing cross-linked gel polymer and a polymerization initiator to a vessel provided with a plurality of mutually parallel rotary stirring shafts each fitted with stirring blades, finely dividing a water-containing gel polymer issuing from the polymerization in progress by the shearing force of stirring blades generated by the rotation of said stirring shafts while allowing the radical aqueous solution polymerization to proceed without interruption, and continuously discharging the resultant finely divided water-containing gel polymer out of said vessel.

Journal ArticleDOI
01 Dec 1985-Polymer
TL;DR: In this paper, a general technique to produce low-density, microcellular, polymeric foams with organic-soluble polymers, in particular polystyrene, is described.


Patent
08 Mar 1985
TL;DR: In this article, a high concentration of one or more extended chain homopolymer, copolymer, or block polymer and certain polyphosphoric acids are prepared for dry-jet wet spinning.
Abstract: Novel compositions comprising a high concentration of one or more extended chain homopolymer, copolymer, or block polymer and certain polyphosphoric acids are prepared. Such compositions are optically anisotropic (liquid crystalline), capable of exhibiting excellent cohesive strength, and are especially suited to the production of high molecular weight ordered polymer fibers by dry-jet wet spinning. These liquid crystalline compositions are capable of being drawn through long air gap distances and spun at exceptionally high spin draw ratios. Fibers, films and other articles formed from these liquid crystalline compositions exhibit exceptionally high physical and heat resistant properties.

Journal ArticleDOI
TL;DR: In this paper, the dehydrogenative coupling of primary silanes to linear polysilanes is catalyzed by Cp2TiR2 (R = CH3 or C6H5CH2) and the degree of polymerization of the polymers thus far obtained is ca 10.

Journal ArticleDOI
01 Jul 1985-Polymer
TL;DR: A review of the dielectric loss spectra of polymers at microwave frequencies has been carried out in this paper, where a large volume of data for low loss polymers (polyethylene, polypropylene and poly(tetrafluoroethylene)), which are used in the communications industry, was available for review.

BookDOI
01 Jan 1985
TL;DR: In this paper, the authors present a number of techniques for studying polymer blends, including pulsed-induction critical scattering (PICF) and X-ray scattering (X-Ray Scattering).
Abstract: 1. Thermodynamic Theory and Experimental Techniques for Polymer Blends.- 2. Glass Transitions and Compatibility Phase Behavior in Copolymer Containing Blends.- 3. Microscopy and other Methods of Studying Blends.- 4. Preparation of Blends.- 5. Light, Neutron and X-Ray Scattering Techniques for Studying Polymer Blends.- 6. Liquid-Liquid Phase Equilibria in Polymer Blends.- 7. Polymer Blend Modification of PVC.- 8. Synthesis of Block and Graft Copolymers.- 9. Block Copolymers Morphological and Physical Properties.- 10. Colloidal Behaviour and Surface Activity of Block Copolymers.- 11. Relationships between Morphology, Structure, Composition and Properties in Isotactic Polypropylene Based Blends.- 12. Rubber-Rubber Blends.- 13. Pure and Applied Research on Interpenetrating Polymer Networks and Related Materials.- 14. Fracture Toughness Evaluation of Blends and Mixtures and the Use of the J Method.- 15. Crazing and Cracking in Glassy Homopolymers.- 16. The Mechanical Properties of Homogeneous Glassy Polymer Blends.- 17. Mechanical Properties of High-Impact Polymers.- 18. Fatigue of High-Impact Polymers.- 19. Yielding and Failure Criteria for Rubber Modified Polymers, Part 1.- 20. Yielding and Failure Criteria for Rubber Modified Polymers, Part 2.- 21. Multiphase Thermosetting Polymers.- 22. Processing and Phase Morphology of Incompatible Polymer Blends.- Seminars.- 1. Pulse-Induced Critical Scattering.- 2. Phase Separation in Polymer Blends.- 3. Thermodynamics of Compatibility in Binary Polymeric Mixtures.- 4. PVC Blending Resins: Properties and Appllications.- 5. Block Copolymers as Homogenizing Agents in Blends of Amorphous and Semicrystalline Polymers.- 6. Study of Copolymer-Homopolymer Blends.- 7. Rubber-Plastics Blends.- 8. Isotactic Polypropylene/Rubber Blends: Effect of Crystallization Conditions and Composition on Properties.- 9. Ethylene-Propylene Rubber and Polyolefin Polymer Blends: Present Situation and Future Trends.

Journal ArticleDOI
TL;DR: In this article, the evidence for the presence of the pyrrole moiety in electrochemically prepared polypyrrole is reviewed together with structural and IR data obtained for the crystalline dimer and trimer of pyrdrugs.
Abstract: The evidence for the presence of the pyrrole moiety in electro-chemically prepared polypyrrole is reviewed together with structural and IR data obtained for the crystalline dimer and trimer of pyrrole. The modification of the mechanical properties of polypyrrole by formation of graft copolymers with polystyrene, by polymerization of the pyrrole monomer within the matrix of a swellable polymer film and by polymerization of the pyrrole on vitreous carbon electrodes is described.

Patent
27 Mar 1985
TL;DR: In this article, a bulk polymerization process for free radical polymerization of vinyl monomers in a wiped surface reactor is described, which permits the manufacture of pressure sensitive adhesive articles by extruding directly from the twin screw extruder onto a substrate.
Abstract: A bulk polymerization process for free radical polymerization of vinyl monomers in a wiped surface reactor is disclosed. Referring to FIG. 1; monomer streams 5 (after purification and silica gel column 2) and 7 are combined with free radical initiator 9 to form a premix 16. Pump 18 transfers the premix stream 22 through static mixer 24 into a wiped surface reactor 27. The reactor can be a counter rotating twin screw extruder which produces polymer stream 36 without the need of solvent and using residence times much shorter than prior art solution or emulsion processes. Some unique pressure sensitive adhesive acrylate polymers have been produced. They are believed to have a relatively high degree of branching. The bulk polymerization process permits the manufacture of pressure sensitive adhesive articles by extruding directly from the twin screw extruder onto a substrate.

Journal ArticleDOI
TL;DR: In this paper, a non-covalent imprinting procedure was used to obtain macroporous polymers with enatio-and substrate-selectivity for some amino acid derivatives.

Patent
17 Dec 1985
TL;DR: In this article, a polyethylene extrusion process is described, in which polymers from about 200,000 to about 4,000,000 are extruded through an aperature at constant concentration and thereafter stretched at a ratio of at least about 3:1 prior to cooling to form a first gel.
Abstract: Solutions of intermediate molecular weight polymers from about 200,000 to about 4,000,000, such as polyethylene, in a relatively non-volatile solvent are extruded through an aperature at constant concentration and thereafter stretched at a ratio of at least about 3:1 prior to cooling to form a first gel. The first gels are extracted with a volatile solvent to form a second gel, and the second gel is dried to form a low porosity xerogel. Stretching occurs with any one or more of the first gel, second gel or xerogel. The polyethylene products produced by our process include products having a molecular weight between about 200,000 and about 4,000,000 a tenacity of at least about 13 grams/denier, a modulus of at least about 350 gram/denier, a porosity of less than 10% by volume, a crystalline orientation function of at least about 0.95, and a main melting temperature of at least about 140° C.

Patent
21 Feb 1985
TL;DR: In this paper, a method for the production of milled supports useful for the preparation of mono-1-olefin polymerization catalysts is provided by comminuting Mg(O)mX 2 -m or Mn(OmX2 -m) and high density ethylene polymer, optionally in the presence of an aromatic phenol and/or an aluminum halide to produce a composite catalyst support.
Abstract: Method for the production of milled supports useful for the preparation of mono-1-olefin polymerization catalysts is provided by comminuting Mg(O)mX 2 -m or Mn(O)mX 2 -m, and high density ethylene polymer, optionally in the presence of an aromatic phenol and/or an aluminum halide to produce a composite catalyst support prior to further comminution with a tetravalent titanium halide to produce a first catalyst component and finally admixture of the first catalyst component with an organoaluminum catalyst compound. Polymerization process employing the novel catalyst system thus produced is also provided.

Journal ArticleDOI
Jorge Heller1
TL;DR: In this article, a linear poly(ortho esters) was used for long-term release studies (6-12 months) and the degradation rate of the polymer was controlled by incorporation of the slightly acidic, low water solubility salt, calcium lactate.

Journal ArticleDOI
TL;DR: An actinomycete, Nocardia sp.
Abstract: An actinomycete, Nocardia sp. strain 835A, grows well on unvulcanized natural rubber and synthetic isoprene rubber, but not on other types of synthetic rubber. Not only unvulcanized but also various kinds of vulcanized natural rubber products were more or less utilized by the organism as the sole source of carbon and energy. The thin film from a latex glove was rapidly degraded, and the weight loss reached 75% after a 2-week cultivation period. Oligomers with molecular weights from 104 to 103 were accumulated during microbial growth on the latex glove. The partially purified oligomers were examined by infrared and 1H nuclear magnetic resonance and 13C nuclear magnetic resonance spectroscopy, and the spectra were those expected of cis-1, 4-polyisoprene with the structure, OHC—CH2—[—CH2—C(—CH3)=CH —CH2—]n—CH2—C(=O)— CH3, with average values of n of about 114 and 19 for the two oligomers.