Group

Wave number (cm1)

Vibration type

Assigned to

-C-H

2985 - 2810

Stretching

PP

-CH2

2950 - 2850

Stretching

HDPE

-CH2

1475 - 1440

Bending

PP

-CH3

1380 - 1370

Bending

PP

-CH2

1470 - 1460

Bending

HDPE

-CH2

730 - 700

Rocking

HDPE