Fig. 1. Principle of Raman spectrum detection platform

Fig. 2. Sample accelerated aging flow chart

Fig. 3. Temperature aging spectrum of polypropylene at each stage

Fig. 4. Temperature aging spectrum of PVC material at each stage

Fig. 5. UV aging spectrum of polypropylene at each stage

Fig. 6. UV aging spectrum of PVC at each stage

Fig. 7. Classification results of polypropylene raw data
(a): Temperature aging LRC; (b): Temperature aging SVM; (c): UV aging LRC; (d): UV aging SVM

Fig. 8. Data preprocessing spectrogram of polypropylene
(a): Baseline correction; (b): Smoothing

Fig. 9. Contribution rate of the first three principal components in Raman spectrum of polypropylene

Fig. 10. Classification effect of polypropylene material data preprocessing
(a): Temperature aging SVM; (b): UV aging SVM