Flow properties of a linear–gel polymer system

Authors

  • S. L. Rosen,

    1. Geer Laboratory for Rubber and Plastics, School of Chemical Engineering, Cornell University, Ithaca, New York
    Current affiliation:
    1. Carnegie Institute of Technology, Pittsburgh, Pennsylvania
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  • F. Rodriguez

    1. Geer Laboratory for Rubber and Plastics, School of Chemical Engineering, Cornell University, Ithaca, New York
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    • Address through August 1965: Union Carbide Corporation, Tonawanda, New York.


  • Paper presented before the American Chemical Society Division of Rubber Chemistry, Detroit, April 20–May 1, 1964.

Abstract

Flow curves (shear stress versus shear rate) were obtained for poly-(ethyl acrylate) containing up to 40% of gel particles over a range of shear rates from 3 × 10−3 to 7 × 103 sec.−1 with a specially designed biconical rheometer and a standard Instron capillary viscometer. Crosslink density of the gels was varied by emulsion-polymerizing ethyl acrylate with 3, 10, and 30% triethyleneglycol dimethacrylate. Particle sizes were varied by adjusting the concentration of emulsifying agent and by seeding techniques. Samples for study were prepared by blending and co-precipitating the linear and gel latices. The addition of gel always increases the shear stress at a given shear rate. However, this effect is greatest at the lowest shear rates. The flow properties of the gelcontaining materials are related quantitatively to those of the linear material through a new parameter, the rate of viscous energy dissipation, and by two material constants. These are a yield stress and a pseudo zero-shear viscosity, both of these being functions of the amount, crosslink density, and particle size of the gel phase.

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