Properties of Lignocellulose Tamarind Fruit Fibers C. Uma Maheswari, 1 B. R. Guduri, 2 A. Varada Rajulu 1 1 Department of Polymer Science and Technology, Sri Krishnadevaraya University, Anantapur 515 003, India 2 Polymers, Ceramics, and Composites, Materials Science and Manufacturing, Council for Scientific and Industrial Research, P.O. Box 395, Pretoria 0001, South Africa Received 25 August 2007; accepted 27 December 2007 DOI 10.1002/app.27915 Published online 7 August 2008 in Wiley InterScience (www.interscience.wiley.com). ABSTRACT: Untreated and alkali-treated fibers from tamarind fruits were analyzed with Fourier transform infrared, chemical, X-ray, and thermogravimetric methods. The morphology of the fibers before and after the alkali treatment was studied with scanning electron microscopy. The tensile properties of these fibers before and after the alkali treatment were also studied. The Fourier transform infrared and chemical analyses indicated lowering of the hemicellulose content by the alkali treatment of the fibers. The tensile modulus increased with the alkali treatment. X-ray diffraction revealed an increase in the crystallinity of the fibers with the alkali treatment. The thermal stabi- lity of the fibers increased slightly with the alkali treatment. Ó 2008 Wiley Periodicals, Inc. J Appl Polym Sci 110: 1986–1989, 2008 Key words: biodegradable; biofibers; biopolymers; compo- sites; renewable resources INTRODUCTION Because of ever-increasing pollution by polymers, the trend is slowly shifting toward the development of environmental friendly polymers and polymer composites. In this direction, the development of green composites is gaining momentum. Several workers 1–14 have used plant- and vegetable-based fibers as reinforcements in the development of green composites. These natural fibers are renewable and environmentally friendly. To identify new natural fibers for use as reinforcements, their properties have to be studied. In this work, we studied the properties of tamarind fruit fibers to assess their suitability as reinforcements. Tamarind is widely used as an important food material in many Asian and African countries. The tamarind fruit has pulp, seeds, and fiber. In India alone, millions of tons of tamarind fibers are going to waste every year after the isolation of the pulp and seeds during food proc- essing. This fruit also has many medicinal values. Because there is not much data available on this fiber, we studied some of its properties, such as its chemical composition, spectral analysis, thermal sta- bility, X-ray diffraction, morphology, and tensile properties. Generally, lignocellulose fibers are sub- jected to a mild alkali treatment to lower their amor- phous hemicellulose content. Such a treatment is expected to improve some of their properties. Hence, the effect of an alkali treatment on these properties was also studied, and the results are reported in this article. EXPERIMENTAL Extraction of the fibers from the fruit Fully ripened tamarind fruits were chosen for extrac- tion of the fibers. After the removal of the shell of the fruit, the pulp and seeds were removed by squeezing. The isolated fibers were washed thor- oughly with occasional shaking to remove any left- over pulp sticking to the fibers. These fibers were then dried in the sun. Some of the fibers were treated with a 5% aqueous NaOH solution and dried before analysis. Fourier transform infrared (FTIR) spectroscopy analysis The fibers were cryogenically cooled and powdered. These powders were diluted to 1% with KBr, and pellets were prepared with a hydraulic press. The FTIR spectra of the untreated and alkali-treated sam- ples were recorded in the 4000–500-cm 21 region on a PerkinElmer 16PC FTIR instrument (Waltham, MA) with 32 scans in each case at a resolution of 4 cm 21 . Chemical analysis The chemical analysis of the untreated and alkali- treated fibers was carried out according to the stand- ard procedure. 15 In this analysis, the percentages of Correspondence to: A. V. Rajulu (arajulu@sify.com). Journal of Applied Polymer Science, Vol. 110, 1986–1989 (2008) V V C 2008 Wiley Periodicals, Inc.