The current study reported the thermal degradation behavior of three paper fibers; cotton,
mechanical& sulfite wood pulp, exposed to dry-heat ageing ate150 °C,130 °C and 105 °C for
one month. The structural changes of fibers were evaluated by SEM, infrared spectroscopy
(FTIR) study and X-Ray Diffraction (XRD). SEM data show that the chemical pulp is more
resistant to heat ageing than the cotton and mechanical pulp in the early stages Dramatic
changes in functional groups on the paper surface, as monitored by infrared spectroscopy,
occurred in the samples before and after ageing. The FTIR results indicated that an
elimination of the band at “amorphous & crystalline” regions under thermal ageing was
occurred.