Question

PET has a Young's, Modulus of 3.5 GPa and PLGA 1.2 GPa. A polymer blend is prepared with 50:50 mixture (PET:PlGA) . What is the Young's, Modulus of this blend (use mixture rule). Calculate the percent load borne by PET when the blend is subjected to a load. If after 10 days, half of PET and one third of PLGA had degraded, what is the Young's Modulus of this blend.

Answer 1

$Young's modulus=Y_{PET}=$ 3.5 GPa, $Y_{GPA}= 1.2 GPa$

It has mixture of 50:50

$Y_m= \frac {Y_{PET}}{2} + \frac {Y_{GPA}}{2}$

$Y_m= \frac {3.5}{2} + \frac {1.2}{2}$

Y$_m= 1.75+.6= 2.35 GPa$

Let . P be the load applied on blend mixture

Total elongation = elongation of 1 + elongation of 2

so here Youngs modulues for mixture after 10 days as per rule of degradation

$Ym =$ $\frac{3.5}{2} +\frac{1.2}{3}= 1.74 + .4= 2.14$ GPa

This Youngs modulus after 10 days