Process for production of high density/high performance binderless boards from whole coconut husk : part I : Lignin as intrinsic thermosetting binder resin

Coconuts are abundantly growing in coastal areas of tropical countries. The coconut husk is available in large quantities as residue from coconut production in many areas, which is yielding the coarse coir fibre. The husk comprises ca. 30 wt.% coir fibres and 70 wt.% pith. Both fibre and pith are extremely high in lignin and phenolic content. The lignin is typically for monocotyledonous plants rich in syringyl with appreciable amounts of p-hydroxyphenyl units. The coir fibre is composed for at least one third of Mason lignin while lower molecular weight phenolics can be found as extractives in considerable amounts, especially in uounger nuts. The thermal behaviour of the original (chemically unmodified) lignin in the plant tissues at temperatures above 140degreesC, where it melts and shows thermosetting properties, has been investigated. This property,of, the coconut husk lignin was explored for application as intrinsic resin in board production, utilising whole fresh husks. Based on this concept, a simple and efficient technology has been developed to produce high strength-high density panels, without addition of chemical binders. Technical details will be reported in following papers. (C) 2003 Elsevier B.V. All rights reserved