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  • 1
    Electronic Resource
    Electronic Resource
    Effect of catalyst on the reactive processing of polyesters with epoxy-functional polymers (1993)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 33 (1993), S. 675-685 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The objective this work was to determine the effects of selected polyester catalysts on the reaction of a polyester with epoxy functional polymers. Polyesters containing various catalyst metals were melt blended with either an ethylene-co-glycidyl methacrylate or a styrene-co-glycidyl methacrylate copolymer. The viscosities of the blends were monitored as a function of mixing time using torque rheometry. In addition, the molecular weight distributions of selected samples were analyzed using gel permeation chromatography. Both the torque rheometry and the gel permeation chromatography results indicate that the polyester reacts with epoxy functional polymers. This reaction occurs under conditions and at processing times which are readily obtainable in conventional melt processing equipment. Furthermore, the reaction kinetics of polyesters with glycidyl methacrylate copolymers are dramatically affected by the nature of the catalyst system used to prepare the polyester. Under the conditions used, antimony catalysts are particularly effective at promoting the reaction between polyesters and the epoxy functionality and the activity of the catalysts studied appears to decrease in the following order: antimony 〉 gallium 〉 tin ≃ titanium 〉 germanium. Manipulation of the polyester catalyst system may offer a method to control the extent of reaction obtained in reactive processing of polyesters with epoxy functional compounds.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760331104
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  • 2
    Electronic Resource
    Electronic Resource
    Impact modification of styrene-acrylonitrile copolymers by methyl methacrylate grafted rubbers (1990)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 30 (1990), S. 1373-1381 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Monodisperse methyl methacrylate grafted latex rubber (MMA-g) particles (0.12-0.13 µm) have been used for the impact toughening of a series of styrene-acrylonitrile (SAN) copolymers of varied AN content. It was found that the MMA-g particles are most effective in toughening SANs containing about 25 to 34% AN. Mechanical properties, interphase adhesion, mechanical dilatometry, and phase morphology by transmission electron microscopy were determined on blends containing 20-30% rubber. Also, the miscibility range of SANs and poly(methyl methacrylate) (PMMA) graft was considered in attempting to analyze the relationships between the mechanical properties and the characteristic features of the blends. Issues relating the impact strength and deformation mechanisms, interphase adhesion, and particle morphology are discussed. It appears that the high impact strength of some of the blends may be caused primarily by certain morphological features such as particle clustering or small interparticle distances. Thus, craze initiation, shear yielding, and significant matrix deformation may all contribute to the overall ductility of the blend.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760302107
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  • 3
    Electronic Resource
    Electronic Resource
    Acrylic acid containing copolymers as reactive compatibilitzers for toughening nylon 6 (1994)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 34 (1994), S. 33-41 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Nylon 6 has been toughened by rubber particles that were dispersed within the matrix via additives that physically interact with the elastomer phase but chemically react with the polyamide phase. To disperse a core-shell impact modifier having a poly(methyl methacrylate) or PMMA shell, most of the work presented is based on the use of a styrene/acrylic acid copolymer containing 8 wt% acrylic acid, SAA8. SAA8 is miscible with PMMA and should located in the PMMA grafted chains of the impact modifier while chemically reacting with the nylon 6 matrix; hence, it should aid in both the dispersal and strenghtening the modifier-matrix interface. Microscopy and mechnical properties confirm that SAA8 does function in this way but less effectively than styrene/maleic anhydride copolymers, which are also miscible with PMMA but evidently react more effectively with the polyamides. The use of ethylene/acrylic acid copolymer for dispersal of the coreshell impact modifier and a styrene/ethylene-butene/styrene block copolymer in nylon 6 was also briefly considered. Low-temperature toughness of the blends proved to be a much more critical test of the effectiveness of such additives than room temperature impact strenght.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760340109
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  • 4
    Electronic Resource
    Electronic Resource
    Phase behavior of blends of poly(vinyl chloride) with an α-methyl styrene/acrylonitrile copolymer (1989)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 29 (1989), S. 581-585 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Poly(vinyl chloride), PVC, is shown to be miscible with an α-methyl styrene/acrylonitrile copolymer, αMSAN, containing 30 percent AN by weight using differential scanning calorimetry for blends prepared by several methods. Melt blending gave single Tg mixtures; whereas, solution techniques gave results that depended on the solvent choice and the manner in which it was removed. These blends do not phase separate on heating prior to significant PVC decomposition (∼250°C) in contrast to PVC/SAN blends which have much lower cloud points. Repulsion between α-methyl styrene and acrylonitrile units in the copolymer is the principal cause for miscibility of this system as shown by an analysis based on a binary interaction model using calorimetry data for low molecular weight liquid analog compounds.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760290903
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  • 5
    Electronic Resource
    Electronic Resource
    Sorption equilibria and kinetics of ethanol in miscible poly(vinylidene fluoride)/poly(methyl methacrylate) blends (1986)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 26 (1986), S. 1218-1227 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: At 35°C miscible blends of poly(vinylidene fluoride) (PVF2), and poly(methyl methacrylate) (PMMA), may be semicrystalline or wholly amorphous and rubbery or glassy depending on composition and prior history. Ethanol is rather soluble in PMMA and plasticizes it, while sorption into PVF2 is rather small. The equilibrium sorption of ethanol into these blends decreases in a well defined manner as the PVF2 content increases and is only slightly affected by prior history of the sample. On the other hand, the kinetics of ethanol sorption varies in a complex manner with composition, ranging from Case II kinetics for glassy blends to Fickian diffusion for rubbery ones, and is a strong function of prior history. Quantitative descriptions are given and discussed in terms of the various mechanistic processes known to occur.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760261710
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  • 6
    Electronic Resource
    Electronic Resource
    Phase stability of ternary blends (1994)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 34 (1994), S. 1788-1798 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The phase behavior of ternary blends of tetramethyl polycarbonate (TMPC), polycarbonate (PC), and styrenic polymers has been examined by experiment and analyzed in terms of thermodynamic theories. The phase boundaries were predicted using both the modified Flory-Huggins theory and the lattice fluid theory. The boundaries predicted using the lattice fluid theory agree best with the experimental results. The experimental phase behavior of ternary blends was compared with binary blends having exactly the same chemical components and compositions except that the TMPC and PC units were present in the form of a copolycarbonate in the binary. The miscible region of these ternary blends is much narrower than that of the corresponding binary blends, even though the entropic and energetic terms of such ternary blends are more favorable than those of the binary blends. It is shown that a negative value of noncombinatorial free energy in multicomponent systems is not a sufficient condition for miscibility, because of asymmetries of mer-mer interactions. A comparison of the stability conditions for these binary and ternary blends shows that increasing the degrees of freedom tends to destabilize the mixture.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760342403
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  • 7
    Electronic Resource
    Electronic Resource
    Elastic fracture of polystyrene solutions (1974)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 14 (1974), S. 560-566 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Based on the assumption of a constant critical shear strain, an expression for the critical stress at the onset of entrance fracture as a function of polymer concentration has been developed. Experimental results with 10-25 percent narrow distribution, high molecular weight polystyrene-benzene solutions show the critical stress to be much lower than that for the polymer melt and in agreement with predicted values. This result is all the more impressive when the contrast in flow behavior at the capillary entrance for melts and solutions is observed. Instead of the rotating toroidal vortices surrounding a 90-deg material entrance cone observed with polystyrene melt, cine movies of the solution flow birefringence patterns in the capillary entrance region reveal only a stagnant zone surrounding a narrow cone less than 20 deg. At fracture, the cone axis moves in a rotary path circulating about the capillary axis without undergoing the flow discontinuities typical of melt behavior.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760140804
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  • 8
    Electronic Resource
    Electronic Resource
    Flow behavior of concentrated solutions of an SBS block copolymer (1970)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 10 (1970), S. 70-78 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The non-Newtonian viscosity of concentrated solutions of a styrene-butadiene-styrene, SBS, block copolymer was measured with a novel capillary viscometer. Polymer concentrations ranged from 0.165 to 0.306 g/cc. Apparent shear rates ranged from 1 to 105 sec-1. Five different solvents were employed. All of the flow curves can be reduced to a single master curve with the same shape exhibited by monodisperse polystyrenes and the Graessley theory. The shift factor for the shear rate axis, τ0, approximately parallels the Rouse relaxation time, τR, but shows a residual concentration and solvent dependence not predicted by the Rouse form. For different solvents at the same concentration, better solvents show a minimum relative zero shear viscosity, η0/ηs, and a maximum ratio τR/τ0. It is concluded that all solvent effects are not adequately incorporated into the zero shear viscosity for the purposes of constructing master plots; however, the shape of the master plot is not affected by the solvent or the polymer block structure.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760100204
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  • 9
    Electronic Resource
    Electronic Resource
    The potential for reuse of plastics recovered from solid wastes (1972)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 12 (1972), S. 157-166 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Plastics in solid wastes is a problem of growing concern. Recycling of wastes is currently believed to be the most acceptable form of disposal in the long run; however, this route is known to be especially difficult for plastics. Recycling would be easier if the various generic types present in solid wastes, mainly polyethylene, polystyrene and poly (vinyl chloride), could be isolated; however, this would be very difficult and expensive. This is a first report on research aimed at evaluating the potential of recycling plastics as a polymer blend of the various generic types. This approach suffers from the difficulty that the different plastics are incompatible and the blend has poor mechanical properties. The extent of this problem is documented with data on many ternary blends employing virgin polyethylene, polystyrene and poly (vinyl chloride) of numerous grades likely to be found in solid wastes. Property degradation was found to be more severe as the complexity of the blend increased, indicating that general municipal wastes could be reused only in very low grade applications, whereas certain commercial wastes might have brighter prospects. Strategies for improving blend properties are outlined.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760120302
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  • 10
    Electronic Resource
    Electronic Resource
    Polymer blends containing poly(vinylidene fluoride). Part I: Poly(alkyl acrylates) (1978)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 18 (1978), S. 677-682 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The transitional behavior of poly(vinylidene fluoride) (PVF2) blends with poly(methyl acrylate) and with poly(ethyl acrylate) was examined by differential thermal analysis and dynamic mechanical testing. Both blend systems were judged to be miscible on the bases of the presence of single, composition dependent glass transitions and of the strong melting point depression of the PVF2 component, Blends of poly(isopropyl acrylate) with poly(vinylidene fluoride) were found to be immiscible. These results suggest that miscibility of the acrylate series depends on a specific attractive interaction between the PVF2 and oxygen within the acrylate and the effect of this interaction is diminished as the hydrocarbon content of the ester is increased.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760180902
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