A
p-v-T device for determining the specific volume of solid and liquid polymer alloys as a function of pressure (up to 200MPa) and temperature (30-350°C) has been constructed. It is a plunger type which consists of a plunger, cylinder, heater and laser displacement meter. The measurement accuracy of the device was within ±2-3%. The
p-v-T properties were determined by the isothermal testing method. We have discussed the effects of the mixing ratio on
p-v-T properties of polymer alloys and the empirical equation of state. The empirical equation of state for amorphous polymers such as PPO, PS and its alloys is presented as follows:
v(
p,
T)=
vo(0,
To)+(
3∑
i=0AiTi+
p1∑
i=0BiTi+
p21∑
i=0CiTi)
Here,
v is specific volumes as a function of pressure and temperature,
vo is specific volume at atomospheric pressure (
p=0) and room temperature (
To). The
Ai (
i=0-3),
Bi and
Ci (
i=0-1) are coefficients of the
p-v-T characteristic each polymers. The values of these coefficients were determined by a least-squares fitting method. The specific volumes of solid and liquid amorphous polymers determined by the em. pirical eq. agree with the measured values to within 1.07% to 1.80% except for PPO. The volume strain
Kv of the solid and molten polymer alloys changed irregularly depending on the mixing ratio. It is minimum when the mixing ratio is PPO/PS=20/80 weight percent.
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