Low Frequency Coupled Oscillator and its Application to High Polymer Study

For the study of dynamical properties of high polymers by low frequency oscillations, a simple torsional coupled oscillator was constructed in which two pendulums of the same type having equal frequency (about 1/2 c.p.s.) were coupled to each other through a test material of cylindrical shape. Two modes of oscillations appear in the motion of the oscillator resulting in generating beats under suitable conditions. By observing the beats, it is possible to obtain the shear modulus and the elastic loss of the material through a simple course of calculation. Polymethyl methacrylate was investigated from about -20°C to about 150°C and anomalous absorption ranges were found at about 130°C and at about 20°C, the latter was considered worthy of mention.