Four denture base polymers were studied by using a torsional pendulum apparatus. Shear modulus and mechanical loss tangent were determined after five seconds over the temperature range 20C to 105C, and hence a transition temperature (TG) was obtained. A polycarbonate had a high TG together with superior elastic properties.
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References
1.
Meares, P.: Polymers: Structure and Bulk Properties, ed I, New York : Van Nostrand, 1965, pp 251-272.
2.
Myerson, R.L. : Effect of Cross-linking or Mechanical Damping and Stiffness of Methacrylates, IADR Preprinted Abstracts , 1962, p 89.
3.
Woelfel, J.B. ; Paffenbarger, G.C.; and Sweeney, W.T.: Dimensional Changes Occurring in Dentures During Processing, J Amer Dent Assoc61:413-430, 1960.
4.
Stafford, G.D. , and Smith, D.C.: Polycarbonates, Dent Pract17:217-223, 1967.
5.
Ferry, J.D. : Viscoelasticity of Polymeric Materials, New York : John Wiley and Co., 1961.
6.
Timoshenko, S., and Goodier, J.N.: Theory of Elasticity, ed 2, New York: Mc-Graw-Hill Book Co., Inc., 1957, p 278.
7.
Eirich, F.R. (ed.): Rheology Theory and Application, New York: Academic Press, Inc., 1958, Vol 2, p 449.
8.
Schnell, H.: Chemistry and Physics of Polycarbonates, ed 1, New York : Interscience, 1964, p 109.
9.
Hoff, E.A.W.: Some Mechanical Properties of a Commercial Polymethylmethacrylate , J Appl Chem2:441-448, 1952.
10.
Brydson, J.A.: Plastic Materials, ed 1, New York: Van Nostrand, 1966, pp 235, 343.
11.
Schmieder, K., and Wolf, K.: Uber die Temperatur und Frequenzabhangikeit des mechanischen Verhaltnis einiger Hoch polymer Stoffe, Koll Zeit127:65-78, 1952.
