Degradation behavior of polymer blend of isotactic polypropylenes with and without unsaturated chain end group

Figures & data

Figure 1 Region of unsaturated chain end groups in ¹H-MR spectrum of MiPP.

Molecular characteristics of ZiPP, MiPP and ZiPP/MiPP polymer blends.

Sample	Meso pentad fraction	Mn	MW/Mn	Chain end group
	mmmm (mol.%)	(g mol.^−1)		content∗∗(mol.%)
ZiPP	97	9.4 10^4	4.9	≈0
MiPP	72	3.0 10^3	2.6	0.7
ZiPP/MiPP (99/1)∗	–	–	–	0.007
ZiPP/MiPP (95/5)∗	–	–	–	0.035
ZiPP/MiPP (90/10)∗	–	–	–	0.07

∗Blend ratio: (wt.%/wt.%). ∗∗Calculation from dilution factor.

Figure 2 Changes in ratio of molecular weights (M_{n, t}/M_{n, 0}) of ZiPP and ZiPP/MiPP during thermal oxidative degradation at 130 °C; M_{n, t} and M_{n, 0} are number average molecular weights after and before thermal oxidative degradation, respectively.

Figure 3 Weight change curves of ZiPP and ZiPP/MiPP at 130 °C in air.

Figure 4 Arrhenius plots of duration of induction period (t_di) for thermal oxidative degradation of ZiPP and ZiPP/MiPP.

Figure 5 Apparent activation energy (ΔE) versus content of unsaturated chain end group.

Value of t_di at various temperatures and apparent activation energies (ΔE).

Sample	tdi(×10^3 s)				ΔE(kJ mol.^−1)
	130 °C	135 °C	140 °C	145 °C
ZiPP	8.4	6.1	4.0	2.3	119
ZiPP/MiPP (99/1)	7.6	5.1	3.6	2.2	113
ZiPP/MiPP (95/5)	5.8	3.8	2.7	1.8	108
ZiPP/MiPP (90/10)	4.7	2.9	2.1	1.6	101