Density, g/cm3	1.44
Young's Modulus, GPa	58
Glass Transition Temperature, oC	220
Refractive Index	1.48

The vibration lines in 1800 - 1600 cm^-1 region are usually asigned to C=O, C=N or C=C bonds. Chemical structure of "ideal" cellulose does not contain any of these groups and, in literature, 1650 cm^-1 peak is interpreted as adsorbed water [1], which is possible as cellulose is hydrophilic. C=O bonds formed as defects during cellulose synthesis can also provide some contribution to the intensity of 1650 cm^-1 peak.

[1] X. Guo, L. Liu, J. Wu, J. Fan, Y. Wu. Qualitatively and quantitatively characterizing water adsorption of a cellulose nanofiber film using micro-FTIR spectroscopy. RSC Adv, 8(2018)4214-4220.

Density, g/cm3	0.91-0.96
Young's Modulus, GPa	0.1-0.5
Glass Transition Temperature, oC	100
Refractive Index	1.51-1.54

Although chemical structure of "ideal" polyethylene does not contain C=O bonds, weak vibration lines corresponding to these bonds can be observed in FTIR-ATR spectrum at 1735 cm^-1 due to photooxidation or synthesis defects [2].

The vibration lines in 3000 - 2800 cm ^-1 region correspond to assymetrical/symmetrical stretch, while the vibration lines in 1490 - 1300 cm ^-1 and 760 - 700 cm ^-1 regions are assigned to bend and rocking, respectively.

[2] L. Chen, T.D. Huan, R. Ramprasad. Electronic Structure of Polyethylene: Role of Chemical, Morphological and Interfacial Complexity. Sci Rep, 7(2017)6128.