7.2 Carbonization of PET
113
Fig. 7.3 a X-ray diffraction patterns, and SEM micrographs of the amorphous carbon materials
produced by heating of PET in air up to different temperatures of b 620 °C and c and d 850 °C,
reprinted from Ref. [24], copyright 2019, with permission from Elsevier
The XRD analysis and SEM morphology of carbon materials produced by heating
in air of PET to 650 and 850 °C are shown in Fig. 6.3. The XRD patterns of the samples
(Fig. 7.3a) indicate the poorly crystalline nature of the carbon materials.
The origin of the endothermic peak observed at 791.2 °C was further investigated.
For this, small pieces of a PET plastic were heated to different temperatures of 650
and 850 °C using a resistance furnace, and the black carbon materials obtained were
characterized. The XRD pattern of the carbon material obtained at 620 °C (7.3a)
shows two broad reflections centered at the 2θ values of 21.2 and 43.4°. The first
peak, corresponding to an interplanar spacing 4.18 Å, can be assigned to the (002)
crystalline planes in short-range ordered hexagonal arrays of turbostratic carbon
[28–30]. This material, which was produced by the pyrolysis of PET at 620 °C, has
also been called disordered graphite [28] or amorphous carbon [31] in the literature.
The second broad XRD reflection extending from the 2θ values of 40–45° has a
maximum at 43.4°. This peak corresponds to the overlapping reflections arisen from
(100) and (101) short-range ordered crystalline planes.
In the hexagonal structure of graphite (JCPDS card No.13-0148), the (002) reflection appears at the 2θ value of 26.6°, which indicates an interplanar spacing of 3.35 Å.
In this crystalline structure, the reflection peaks arisen from (100) and (101) plans
appear at the 2θ values of around 42.4 and 44.4°, respectively. The XRD patterns of
amorphous carbon materials obtained by heating of PET exhibit a large deviation of
113
Fig. 7.3 a X-ray diffraction patterns, and SEM micrographs of the amorphous carbon materials
produced by heating of PET in air up to different temperatures of b 620 °C and c and d 850 °C,
reprinted from Ref. [24], copyright 2019, with permission from Elsevier
The XRD analysis and SEM morphology of carbon materials produced by heating
in air of PET to 650 and 850 °C are shown in Fig. 6.3. The XRD patterns of the samples
(Fig. 7.3a) indicate the poorly crystalline nature of the carbon materials.
The origin of the endothermic peak observed at 791.2 °C was further investigated.
For this, small pieces of a PET plastic were heated to different temperatures of 650
and 850 °C using a resistance furnace, and the black carbon materials obtained were
characterized. The XRD pattern of the carbon material obtained at 620 °C (7.3a)
shows two broad reflections centered at the 2θ values of 21.2 and 43.4°. The first
peak, corresponding to an interplanar spacing 4.18 Å, can be assigned to the (002)
crystalline planes in short-range ordered hexagonal arrays of turbostratic carbon
[28–30]. This material, which was produced by the pyrolysis of PET at 620 °C, has
also been called disordered graphite [28] or amorphous carbon [31] in the literature.
The second broad XRD reflection extending from the 2θ values of 40–45° has a
maximum at 43.4°. This peak corresponds to the overlapping reflections arisen from
(100) and (101) short-range ordered crystalline planes.
In the hexagonal structure of graphite (JCPDS card No.13-0148), the (002) reflection appears at the 2θ value of 26.6°, which indicates an interplanar spacing of 3.35 Å.
In this crystalline structure, the reflection peaks arisen from (100) and (101) plans
appear at the 2θ values of around 42.4 and 44.4°, respectively. The XRD patterns of
amorphous carbon materials obtained by heating of PET exhibit a large deviation of