Showing papers on "Polymer blend published in 1983"

Microporous sheet material, method of making and articles made therewith

Abstract: A method of making a microporous material is provided which comprises the steps of melt blending crystallizable thermoplastic polymer with a compound which is miscible with the thermoplastic polymer at the melting temperature of the polymer but phase separates on cooling at or below the crystallization temperature of the polymer, forming a shaped article of the melt blend, cooling the shaped article to a temperature at which the polymer crystallizes to cause phase separation to occur between the thermoplastic polymer and the compound to provide an article comprising a first phase comprising particles of crystallized thermoplastic polymer in a second phase of said compound, orienting the article in at least one direction to provide a network of interconnected micropores throughout. The microporous article comprises about 30 to 80 parts by weight crystallizable thermoplastic polymer and about 70 to 20 parts by weight of the compound. The oriented article has a microporous structure characterized by a multiplicity of spaced randomly dispersed, equiaxed, non-uniform shaped particles of the thermoplastic polymer which are coated with the compound. Adjacent thermoplastic particles within the article are connected to each other by a plurality of fibrils consisting of the thermoplastic polymer. The fibrils radiate in three dimensions from each particle. The compound may be removed from the sheet article. e.g., by solvent extraction. The preferred article is a sheet material.

Melt flow of polymer blends

Abstract: The production of polymer blends increases at a rate of about 13 percent/y. Most of the commercial blends are multiphase systems of complex morphology, determined by the thermodynamic properties of the components and the rheology. Since the diffusion rates are relatively low, the blends are seldom at equilibrium. In most cases, the blend products have properties imposed by the morphology, created by a particular combination of the thermal and deformational history. There are three main reasons for studying the melt flow of blends: optimization of the processing conditions, search for the appropriate means to generate the desired morphology, and the interest in the basic study of the rheology of these complex systems. In this paper the results published during the last five years are reviewed. The data for polymer blends are compared with those obtained for simpler model systems: liquid mixtures, emulsions, and polymer blends. From the rheological point of view, the blends are divided into three groups: those where viscosity shows positive deviation from the log-additivity rule, PDB, those where the opposite effect is observed, NDB, and the remaining mixed-behavior systems, PNDB. To PDB belong the miscible blends and those with strong inter-domain interactions. To NDB belong those where the interactions are weak. To PNDB belong the blends in which there is a concentration-dependent transition of structure. The shear dependent properties of blends are also discussed.

The effect of flow on the miscibility of a polymer blend

Abstract: Results indicating the extent to which flow in a miscible polymer blend can displace the phase separation temperature are reported. Data were obtained on the system, polystyrene/poly (vinyl methyl ether), in the temperature ranges where it undergoes exsolution upon heating. The theoretical framework for the observed flow‐induced miscibility is described.

Chain dimensions and interaction parameters in neutron scattering from polymer blends with a labeled component

Abstract: Etude theorique, application a deux melanges d'oligomeres de polyethyleneglycol methoxyle-polypropeneglycol methoxyle et polystyrene-polybutadiene

Nonblocking elastomeric polymer blends of ABA block copolymer and ethylene-vinyl acetate copolymer

Abstract: Thermoplastic elastomeric films comprise from about 40% to about 80% of an elastomeric block copolymer and from about 20% to about 60% of an ethylene-vinyl acetate copolymer. The block copolymer has at least two monoalkenyl arene polymer end blocks and at least one elastomeric conjugated diene midblock. The monoalkenyl arene polymer blocks comprise from about 8% to about 55% by weight of the block copolymer. The block copolymer has a melt index of less than about 10. The ethylene-vinyl acetate copolymer comprises from about 22% to about 33% vinyl acetate and has a melt index of less than about 0.6. The film is from about 0.03 mm to about 0.15 mm in thickness.

Effect of molecular weight on polymer blend phase separation kinetics

Abstract: Etude par la technique de fluorescence d'excimere de melanges polystyrene-polymethyl vinyl ether. La demixtide se fait par decomposition spinodale. Influence de la polydispersite du polyether

A comparison of miscible binary blend interaction parameters measured by different methods

Abstract: Miscible blends of the polyhydroxy ether of bisphenol-A, Phenoxy, with a series of aliphatic polyesters were studied using melting point depression analysis and sorption to obtain the Flory-Huggins polymer-polymer interaction parameter, B. The B values obtained from these measurements were found to agree well in sign, magnitude, and variation with ester repeat structure and to also agree well with B values measured calorimetrically for mixtures of low molecular weight compounds with structures which are analogous to those of the polymers. These comparisons suggest that the same mechanisms are responsible for the exothermic heats of mixing measured directly for the analog compounds and indirectly for the miscible polymer blends. For this general system, evidence is provided which suggests that hydrogen bond formation between the hydroxyl group on Phenoxy and the ester moiety is probably responsible for the exothermic interactions and polymer blend miscibility observed.

Low gloss carbonate polymer blends

Abstract: Blends of carbonate polymer, such as a polycarbonate of bisphenol-A, and a rubber-modified copolymer, such as an acrylonitrile/butadiene/styrene (ABS) resin prepared by mass, bulk or mass suspension polymerization techniques, or by agglomerating particles prepared by emulsion polymerization techniques, exhibit good physical properties and a low gloss finish. Such blends are particularly useful in the manufacture of molded parts. Such blends are color stable and exhibit small amounts of yellowing.

Heat-sterilizable polyolefin compositions and articles manufactured therefrom

Abstract: Heat-sterilizable films are made from a polymer blend of about 10 to about 60 wt % random propylene-ethylene copolymer containing from about 1 to about 6 wt % ethylene-derived units and about 40 to about 90 wt % linear low density polyethylene. The films are especially useful in the manufacture of collapsible parenteral solution bags and overwraps.

New approach to probing polymer and polymer blend structure using electronic excitation transport

Abstract: A theoretical study of electronic excitation transport in polymer systems is presented GYt), the time-dependent ensemble-averaged probability that the excitation is on the originally excited chromophore, is calculated by using an approach involving a density expansion It is shown that this quantity is a direct observable in a time-resolved fluorescence depolarization experiment The effects of the finite volume associated with a single polymer coil or a small aggregate in a polymer blend are considered explicitly Calculations are presented for systems having a Gaussian ensemble-average segmental distribution The influences of density, volume, and aggregation are illustrated Gg(t) can yield reliable information about the local chromophore distribution of systems for which a lack of knowledge of the number of excimer traps prevents quantitative application of trapping experiments The approach described here should be particularly valuable in obtaining structural information about very low concentration guest polymers in polymer blends and solutions

The Influence of Interfacial Structure on the Flexural Strength of E-glass Reinforced Polyester

Abstract: Simultaneous mechanical and molecular characterization of a composite system has been attempted with respect to the interface. The mechanical properties of an E-glass cloth/ y-methacryloxypropyltrimethoxysilane (γ-MPS)/bisphenol-A-fumarate polyester resin composite system were studied as a function of the amount of γ-MPS coupling agent present on the glass fiber surface. Fourier transform infrared diffuse reflectance spectroscopy was used to determine the amount and structure of γ-MPS on the glass. This structure consists of two clearly distinguishable regions: physisorbed layers of γ-MPS which can be dissolved by organic solvents, and chemisorbed layers which are insoluble. The physisorbed layers of γ-MPS reduced the strength of the polyester composite. A polymer blend consisting of siloxane oligomer of γ-MPS and bisphenol-A polyester was also investigated as a model of the silane interphase. Results from this model study are in agreement with the polyester composite data.

Melt rheology of polymer blends the morphology feedback

Abstract: Relations morphologie des melanges (tailles et formes des phases du melange) et proprietes rheologiques a l'etat fondu (viscosites, elasticites). Le melangeage a une influence sur la morphologie

Ethylene polymer blend

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.

Thermoplastic polymer compositions comprising aromatic polyether and an inorganic filler

Abstract: A thermoplastic polymer composition having well-balanced physical properties, especially impact strength and gloss, is provided, which comprises an aromatic polyether resin, a styrene polymer and/or a rubber-enforced styrene polymer containing a cross-linked conjugated diolefin polymer in a dispersed island state, an inorganic filler, and a thermoplastic elastomer selected from styrene-conjugated diolefin copolymers and styrenic polymer grafted polyolefin.

Miscible polymer blends containing poly(2-alkyl-2-oxazoline)

Abstract: Miscible blends of poly-2-oxazolines and thermoplastic polymers are disclosed herein. These blends exhibit a single glass transition point indicative of a miscible blend. The blends of this invention are useful as membranes, particularly separation membranes for mixtures of organic compounds or organic compounds and water and a perevaporation process.

Water soluble films of polyvinyl alcohol polyvinyl pyrrolidone

Abstract: Films which are rapidly soluble in cold and warm water are formed from blends of water soluble polyvinyl alcohol (partially hydrolyzed polyvinyl acetate) and polyvinyl pyrrolidone. The polymers are compatible and form homogeneous mixtures from which clear, transparent, non-tacky, easily handleable, mechanically strong films can be formed. The films are stable at both low and high humidity conditions, i.e., the films do not become brittle or tacky and retain their high rates of dissolution in water even after being stored in low or high humidity environments at both high and low temperatures. Further, improvements are achieved by incorporating a plasticizer into the polymer blend. The films are also heat sealable and biodegradable.

Novel polymer blends

Abstract: Blends are disclosed of a clear polyurethane plastic and a minor amount (up to 30 parts by weight per 100 parts by weight of blend) of an incompatible polymeric impact modifier. The resulting blends exhibit properties (high impact resistance, high flexural modulus and resistance to heat) comparable to those of engineering plastics such as nylon.

Vulcanizable polymeric compositions containing a zinc dimethacrylate adjuvant and method for preparing the adjuvant

Abstract: Vulcanizable polymeric compositions comprising certain rubbery polymers or polymer blends, a zinc dimethacrylate adjuvant having a surface area of from about 3.7 to about 5.4 m2 /g or more and a peroxide curing agent are provided. Polymeric compositions which contain 25 parts by weight or more of the zinc dimethacrylate adjuvant per 100 parts by weight of rubbery polymer in the absence of reinforcing fillers exhibit excellent strength and hysteresis characteristcs when cured. The surface area of the zinc dimethacrylate adjuvant along with its method of preparation are extremely important factors in the excellent properties obtained when polymeric compositions containing the adjuvant are cured.

Flame-retardant polymer mixtures

Abstract: Die Erfindung betrifft flammwidrige Polymermischungen aus Polycarbonat, Styrolpolymerisat und/oder Pfropfpolymerisat sowie Polyphosphat, die organische Chlor- und Bromverbindungen und Polytetrafluorethylen enthalten konnen. The invention relates to flame retardant polymer blends of polycarbonate, styrene polymer and / or graft polymer and polyphosphate, organic chlorine and bromine compounds, and may contain polytetrafluoroethylene.

Silica-polymer mixtures

Abstract: A process is provided for producing a silica-synthetic polymer mixture by mixing silica, water and an alkyl trimethylammonium halide, adding this mixture to a latex of the synthetic polymer, coagulating the mixture and recovering the silica-polymer mixture. Such mixtures may be used for the production of rubbery vulcanizates such as shoe soles, light colored shaped articles and the like.

Blends of vinyl halide-polyolefin graft polymers and SMA polymers

Abstract: A novel thermoplastic polymer composition comprises a blend of a high impact vinyl halide polymer, particularly a vinyl halide-polyolefin graft polymer, and a copolymer of styrene and maleic anhydride and modifications thereof.

Expansible polymer molding process and the resultant product

Abstract: A method for forming a molded polymer foam structure comprising expanding solvent imbibed polymer particles selected from the group consisting of a polyetherimide, a polycarbonate and a polyphenylene oxide-polystyrene blend and fusing the expanded particles together in a mold.

Self-curing water dispersed polymer blends

Abstract: A self-curing water dispersed copolymer particularly useful for coatings for interiors of beverage containers comprises a self-curing water dispersed copolymer of polymerized ethylenic monomers, including alkylol acrylamide monomer and functional monomer, produced by copolymerizing the monomers in the presence of an epoxy phosphate additive.