# Effect of LNR-g-MMA on the Mechanical Properties and Lifetime Estimation of PLA/PP Blends
## 3 Results and Discussion
### Thermal Analysis
#### 3.4.3 Lifetime Estimation  
Figure 10 shows the thermal lifetime behavior estimated for PLA, PP, and PLA/PP (70:30 wt%) blends without and with LNR\(-\)g\(-\)MMA obtained for different failure temperatures. In this case, the expected lifetime was calculated based on the sample's 0.05 conversion degree at a heating rate of 20 \({}^{\circ}\)C/min during thermogravimetry tests. The lifetime values of PLA, PP, and PLA/PP (70:30 wt%) blend without and with LNR\(-\)g\(-\)MMA for a temperature range between 25 and 150 \({}^{\circ}\)C were calculated using Equation (10) and are plotted in Figure 10. Regardless of the method employed for estimation, it is obvious that the lifetime of all blends was temperature dependent and was exponential with an increase in temperature. The lifetime estimation, determined using a conversion degree failure of 0.05 at a heating rate of 20 \({}^{\circ}\)C/min, of PLA, PP, and the PLA/PP (70:30 wt%) blend with LNR\(-\)g\(-\)MMA of 0.0, 2.5, 5.0, and 10.0 phr was 2.95 \(\times\) 10\({}^{3}\), 3.37 \(\times\) 10\({}^{10}\), 3.54 \(\times\) 10\({}^{7}\), 2.30 \(\times\) 10\({}^{6}\), 2.99 \(\times\) 10\({}^{5}\), and 6.23 \(\times\) 10\({}^{3}\) years at 25 \({}^{\circ}\)C and 1.00 \(\times\) 10\({}^{2}\), 2.56 \(\times\) 10\({}^{8}\), 3.85 \(\times\) 10\({}^{5}\), 3.48 \(\times\) 10\({}^{4}\), 5.95 \(\times\) 10\({}^{3}\), and 2.03 \(\times\) 10\({}^{2}\) years at 50 \({}^{\circ}\)C, respectively. The increase in temperature tended to diminish the durability of the material. Consequently, the temperature affected the entire lifetime of the material. Because a lifetime is based on activation energy, PP had a longer lifetime than PLA and PLA/PP (70:30 wt%) blend. The  
\begin{table}
\begin{tabular}{l c c c c c} \hline \hline \multirow{2}{*}{**Polymer Sample**} & **PLA/PP/LNR-** & \multirow{2}{*}{**T\({}_{\text{i}}\) (\({}^{\circ}\)C)**} & \multirow{2}{*}{**T\({}_{\text{m1}}\) (\({}^{\circ}\)C)**} & \multirow{2}{*}{**T\({}_{\text{m2}}\) (\({}^{\circ}\)C)**} & \multirow{2}{*}{**T\({}_{\text{f}}\) (\({}^{\circ}\)C)**} \\  & & & & & \\ \hline \(\beta\) = 10 \({}^{\circ}\)C/min & & & & \\ PLA & 100:0.0 & 295 & 314 & - & 335 \\ PP & 0:100:0 & 445 & 482 & - & 495 \\ PLA/PP/0.0 phr & 70:30:0.0 phr & 340 & 357 & 498 & 490 \\ PLA/PP/2.5 phr & 70:30:2.5 phr & 336 & 351 & 492 & 479 \\ PLA/PP/5.0 phr & 70:30:5.0 phr & 325 & 345 & 462 & 476 \\ PLA/PP/10.0 phr & 70:30:10.0 phr & 305 & 320 & 445 & 575 \\ PLA & 100:0.0 & 315 & 329 & - & 350 \\ PP & 0:100:0 & 380 & 497 & - & 520 \\ PLA/PP/0.0 phr & 70:30:0.0 phr & 350 & 370 & 506 & 518 \\ PLA/PP/2.5 phr & 70:30:2.5 phr & 345 & 367 & 503 & 515 \\ PLA/PP/5.0 phr & 70:30:5.0 phr & 335 & 356 & 489 & 510 \\ PLA/PP/10.0 phr & 70:30:10.0 phr & 320 & 346 & 475 & 495 \\ PLA & 100:0.0 & 340 & 364 & - & 380 \\ PP & 0:100:0 & 490 & 508 & - & 530 \\ PLA/PP/0.0 phr & 70:30:0.0 phr & 370 & 380 & 514 & 528 \\ PLA/PP/2.5 phr & 70:30:2.5 phr & 365 & 378 & 512 & 526 \\ PLA/PP/5.0 phr & 70:30:5.0 phr & 350 & 375 & 504 & 524 \\ PLA/PP/10.0 phr & 70:30:10.0 phr & 335 & 350 & 502 & 520 \\ PLA & 100:0.0 & 360 & 376 & - & 390 \\ PP & 0:100:0 & 530 & 562 & - & 570 \\ PLA/PP/0.0 phr & 70:30:0.0 phr & 385 & 405 & 523 & 536 \\ PLA/PP/2.5 phr & 70:30:2.5 phr & 380 & 394 & 522 & 535 \\ PLA/PP/5.0 phr & 70:30:5.0 phr & 360 & 375 & 520 & 530 \\ PLA/PP/10.0 phr & 70:30:10.0 phr & 350 & 374 & 513 & 529 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Thermal degradation temperatures of PLA, PP, and PLA/PP (70:30 wt%) without and with compatibilizer.  
PLA/PP (70:30 wt%) blend without LNR\(-\)g\(-\)MMA had a longer lifetime than PLA/PP (70:30 wt%) blends with LNR\(-\)g\(-\)MMA content. This study showed how activation energy affected the thermal performance of PLA/PP/LNR\(-\)g\(-\)MMA blends, significantly shortening their lifetime.  
Figure 8: Plots obtained from the TGA curves at different degrees of conversion of **(a)** PLA, **(b)** PP, and PLA/PP blends with LNR\(-\)g\(-\)MMA of **(c)** 0.0, **(d)** 2.5, **(e)** 5.0, and **(f)** 10.0 phr based on the KAS method.