Investigation of anatomical and chemical characteristics of Calotropis procera wood

In this study morphological characteristics and chemical composition of Calotropis procera species were analysed with the goal of applying its wood in wood and paper industry. This species has been studied due to its resistance to drought, its numerous applications in industries such as rubber and textile industry and medicinal properties of its root bark in treatment of various diseases. Also it has three fibers in seed pod, bark and stem. This species was sampled from Jiroft in Kerman province of Iran.
Material and For determining the chemical composition, samples were taken from 1/3 of stem height and powder of wood was prepared according to standard T257om-85 of regulations TAPPI. Content of holocellulose, cellulose, lignin, ash, acetone-soluble extractive and hot water extractive were measured according to TAPPI methods. Fibers in stem, stem bark, branch and branch bark were separated by Franklin method. Dimension of fibers were measured with electronic microscope. Anatomical studies were performed based on International Association for Wood Anatomy (IAWA).
The anatomical characteristics, fiber biometry and chemical compounds of this species were recorded. Mean values of trunk and Bark fibers length were 1.09 and 15 mm, respectively. Branch bark of this plant has long fibers and its trunk fiber length was in the range of poplar wood fibers. Fiber diameter, cavity diameter and wall thickness of trunk fiber were 37.5, 29.0, and 4.37 µm, respectively. The biometry factors include raunkel, flexibility, and slenderness ratios of fibers were determined 30.65, 76.53, and 28.92, respectively. Results of trunk chemical compounds analysis showed that, the trunk is composed of %58.76 cellulose, %25.6 lignin, %1.56 acetone-soluble extractives, %6.5 hot water soluble extractives and %1.66 ash.
According to the results of the chemical analysis, this species has low extractives and ash content but the amount of lignin was high. Cellulose content of this species is higher than the typical cellulose content of hardwood and softwood species. This feature is an important characteristic in paper making industry due to its direct effect on pulping efficiency. Therefore regarding the suitability of trunk fibers and high cellulose contents, this species can be used in lignocellulosic industries such as paper making.