**3.2 XRD analyses**

The XRD spectrum of grafted pine magnetite composite with acrylamide is shown in **Figure 2a**. The prominent peaks at 2*θ* values of 30.5°, 38.7°, 43.9.0°, 59.8° and 63.7° corresponding to (220), (311), (400), (422), (511), respectively, attributes to the cellulose peaks due to the presence of iron oxide magnetite composite and crystal planes of grafted pine magnetic composite respectively [18]. The composite has shown a cubic crystal structure. It is observed that diffraction intensity of the broad peak at 43.9° was weakened indicating that the crystallinity of the PMC decreased after grafting. This phenomenon might be due to the strong interaction of covalent bonds between the PMC and the acrylamide.

### **3.3 TGA analyses**

The TGA and DTG curves shown in **Figure 3a** demonstrate the thermal stability of grafted pine magnetite composite. The incorporation of the Fe3O4 magnetite composite showed the changes in the thermal properties of the cellulose. The initial thermal decomposition of GACA occurred at 100–240°C temperature range which corresponds to loss of water molecules and volatile compounds. The second stage thermal decomposition in the temperature range 380–640°C may be due to the breakdown of the polymer matrix and cross-links between different polymeric chains. The last stage of decomposition at a temperature of 700°C corresponds to the lignin degradation [19]. Grafting with acrylamide presented a better thermal stability due to the different types of covalent bonds in the grafting of copolymer backbone [20]. Differential thermal analysis (DTA) showed endothermic peaks associated with degradation of various materials. The degradation behaviour exhibited two stage decomposition effects. Observation at different temperatures (380–620°C) was attributed to the cellulose decomposition at low temperature and grafted acrylamide composite at higher temperatures. This confirmed the stabilizing effect of the incorporation of Fe3O4 composite onto acrylamide.

**Figure 2.** *XRD spectrum for GACA.*

due to the presence of extracted lignin in pine cone. Clearly, the COOd peak was

which represent the increase in the internal surface of the pine cone and a new peak was found at 567 cm<sup>1</sup> which was assigned to the vibration of FedO band of Fe3O4. The FT-IR spectrum of GACA (**Figure 1(b)**) shows a slightly broad band observed at 3389 cm<sup>1</sup> ascribed to the existence of OHd and dNH groups [15]. The compressed peak at 1654 cm<sup>1</sup> corresponds to a carbonyl functional group of

, CdH aliphatic peaks were observed at 1416 cm<sup>1</sup>

converted to esters at 1622 cm<sup>1</sup>

*Waste in Textile and Leather Sectors*

*(a) FT-IR spectrum for PMC and (b) FT-IR spectrum for GACA.*

**Figure 1.**

**160**

**Figure 3.** *TGA and DTA curves for GACA.*

**Figure 4.** *(a) TEM image and (b) size distribution of GACA.*
