Chemical and crystalline structure properties of hemp (Cannabis sativa L. ) bast fibres pulp obtained with alkaline and acidic processes

Chemical And Crystalline Structure Properties Of Hemp ( Cannabis Saliva L.) Bast Fibres Pulp Obtained With Alkaline And Acidic Processes Hemp {Cannabis sativa L.) bast fibres are an appropriate raw material for pulping, evaluated ratio of chemical component. But cooking and beating time of hemp bast fibres pulp is very long, so it has some disavantages. In this study; acedic acid / water, ethanol / water and alkaline sulphite pulping processes were done by using hemp bast fibres, and then chemical and crystalline structure properties were investigated in pulp obtained with three different methods. Meanwhile, the reasons of disavantages of hemp bast fibres were examined. According to chemical analyses of these pulp, it was determined that carbohydrate content were changed between 82.30%-96.53%. Alpha-cellulose contents of these pulp were found between 60.19%-89.27%. Alpha-cellulose content pulp obtained hemp bast fibres were found higher than other raw material used in pulping. When the results of solving experiments of pulps were examined, it was found that unpureness in pulp were remained bounds to reaction media in pulping. Lignin content was determined as 6.59% in hemp bast fibres, but this ratio was decreased to 2.58% with alkaline sulphite pulping process. While investigating the crystalline structure properties of hemp bast fibres, the crystallinity and disorder parameter were determined as 36.6% and 0.3, respectively. By using alkaline and acidic pulping processes, the crystallinity and disorder parameter were changed between 39.5%-54.6% and 0.2-1.7, respectively. It was found that disorder parameter at the least degree, so hemp bast fibres pulp obtained with three different processes had higher crystalline cellulose proportion. For these reasons, it is possible that hemp bast fibres is resistant to cooking chemicals and mechanical effects. Keywords: Cellulose, Crystalline Structure, Crystallinity, HPLC, X-ray, Moj DC ^ «.«**