Evaluating the performance of hemp bast fibres in the production of packaging paper using different …
XRD analysis XRD measurements were performed to investigate the change in crystallinity of the hemp bast fibres after different treatments. Figure 3 shows the XRD patterns of raw, cooked and beaten hemp bast fibres.
Fig. 3. X-ray diffraction patterns of raw, cooked and beaten hemp bast fibres According to Fig. 3., the XRD patterns of the hemp bast fibres (raw, cooked, beaten) exhibited identical peaks at three different planes, including 2θ = 14.8° (plane 101), 2θ = 16.5° (plane 101) and 2θ = 22.7° (plane 002). Peaks at 14.8° and 16.5° were more intense for cooked and beaten hemp bast fibres when compared to raw material. During cooking, hemicellulose and lignin were dissolved, leaving just the crystalline components. Since the amorphous parts are effectively removed by this phenomenon, the peaks were sharper. The degree of crystallinity of raw, cooked and beaten hemp bast fibres were 51%, 56% and 57%, respectively (according to Segal’s method) . The results show that the degree of crystallinity of hemp bast fibres increased aft er cooking. Gümüşkaya and Usta [2006] also stated that the degree of crystallinity of hemp bast fibre increases when the amorphous parts of cellulose are chemically degraded. The crystallinity of cooked hemp bast fibres increased by 1% after beating. The number of amorphous regions increased after beating the cooked hemp bast fibres, resulting in a decrease in the degree of crystallinity [ Eroğlu and Usta 2004]. This unexpected increase in the degree of crystallinity indicated that the applied beating did not affect the fibrillation of the fibres, as also indicated by the OM results of this study. FTIR analysis The raw material contained hemicellulose and lignin, and since pulping is meant to remove lignin and hemicellulose, the interpretation of the FTIR analysis results
Made with FlippingBook Annual report maker