Dynamic shear modulus and damping have been determined on poly styrene filled with glass beads which have been given surface treatments, ground glass, ground rock salt, and foams made by extracting the salt with water. Soaking the glass bead filled polystyrene in water and then redrying produces a permanent increase in damping. Data on ground glass and on rock salt composites illustrate the importance of maximum packing volume on the modulus. It is shown that moduli determined by torsional tests or by flexural tests are in error due to a polymer-rich skin. A simple method is given for correcting this error.
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References
1.
L.E. Nielsen , "A Recording Torsion Pendulum for the Measurement of the Dynamic Mechanical Properties of Plastics and Rubbers," Rev. Sci. Instr., Vol. 22 (1951 ), p. 690.
2.
L.E. Nielsen , "Dynamic Mechanical Properties of Filled Polymers ," Appl. Polym. Symp., No. 12 (1969), p. 249.
3.
T.B. Lewis and L.E. Nielsen, "Dynamic Mechanical Properties of Particulate-Filled Polymers," J. Appl. Polym. Sci., Vol. 14 ( 1970), p. 1449.
4.
J. Ritter, "Sphere-Filled Plastic Composites," Appl. Polym. Symp. , No. 15 (1970), p. 239.
5.
M.A. Durand , "The Temperature Variation of the Elastic Moduli of NaCl, KCl, and MgO," Phys. Rev., Vol. 50 (1936), p. 449.
6.
L.E. Nielsen and T.B. Lewis, "Temperature Dependence of Relative Modulus in Filled Polymer Systems," J. Polym. Sci., Part A2, Vol. 7 (1969), p. 1705.
7.
S.W. Tsai, "Formulas for the Elastic Properties of Fiber-Reinforced Composites ," Monsanto/Washington University ONR/ARPA Association Report HPC-68-61, AD834851 (1968).
8.
J.C. Halpin , "Stiffness and Expansion Estimates for Oriented Short Fiber Composites," J. Compos. Mater., Vol. 3 (1969), p. 732.
9.
J.E. Ashton, J.C. Halpin, and P.H. Petit, Primer on Composite Analysis, Technomic Publ. Co ., Westport, Conn. (1969).
10.
L.E. Nielsen , "Generalized Equation for the Elastic Moduli of Composite Materials," J. Appl. Phys., Vol. 41 (1970), p. 4626.
