Extraction of high quality cellulose from the stem of Calotropis procera

Abstract

The stem of Calotropis procera (Vern. Aak) is a source of natural cellulosic bast fibres wherein the commercially valuable properties like cellulose content, fiber strength and fiber elongation are found to be intermediate between that of cotton and linen. Other than high tensile and abrasive strength, fibers from C. procera possess more weight per square meter than the cotton fibers. We have been trying to standardize protocol for isolation of high quality cellulose from Calotropis. We have compared the effects of alkali treatment and acid treatment on the yield and quality of cellulose fibers obtained. When the retted stems of C. procera were treated with 0.5N NaOH, the natural yield of cellulose fibers was approximately 6%. The efficiency of cellulose extraction was increased to 26% when the fibers were treated with 80% acetic acid and concentrated nitric acid (10:1). The percentage composition of cellulose was determined through infrared spectroscopy and acid detergent fiber method by refluxing. Acid treated fibers show higher percentage of cellulose content (85%) compared to the alkali treated method. The cellulose content in fibers obtained through acid treatment is comparable with that of cotton and better than linen. The acid treated method requires significantly less time compared to the alkali treated method. Since Calotropis is a wildly growing shrub in major parts of India, its use as a source of excellent cellulose fibers might have enormous economical implications.