7.1 Poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) is blended with polystyrene. Compare the predictions of the inverse rule of mixtures and the logarithmic rule of mixtures (see Sec- tion 4.3.4) by plotting the calculated Tg of the blend against the weight fraction of PS. Tg values obtained from DSC measurements are as follows: TASS 010 Wt% PPO T, (C) 105 121 140 158 185 216 0 20 40 60 80 100