The current study reported the thermal degradationbehavior 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 m...