STUDIES ON THE PULPING AND CHEMICAL CONSTITUENTS OF PINUS CARIBAEA

Abstract

Pinus is genera of plants belonging to the family Pinaceae of the order coniferales and of class Gymnosperms. The genus pine, being a source of resins, turpenes and paper pulp is very important amongst the conifers in India. Pinus caribaea grows in Bahama islands, Western Cuba and Nicaragua, it is mainly distributed in islands of Carribean and costal of Central America . The altitude range ofPinus caribaea is being taken from sea level to 300m. Pinus caribaea' is a fast growing exotic pine species in comparision to other pines species . Studies have thus been carried out to cover the pulping and chemical consti-tuents of Pinus caribaea . On reviewing the past literature ,it is evident that no systematic work is reported in literature on the chemistry of Pinus caribaea and the reactions occuring on the chemical constituents during pulping so far. This study will not only give the chemical composition of the wood but will also help in better under standing its reactic during pulping and bleaching for different grade of pulps used for various types of papers. This study will also help in using alternative raw materials to the paper industry. The subject matter of the thesis is broadly divided into six chapters. A summarised account of the results of above mentioned investigations are given as below: SUMMATIVE ANALYSIS Pinus cariba-ra logs were debarked. Splitted and chipped on chipper, the chips wereof 1.5 to 2.5 cm in size. For chemical analysis the chips were disintegrated into wood meal in a laboratory Willey Mill. The wood meal passing through 410 mesh but retained on 60 mesh was used for elemental and proximate analysis. P.caribaea wood was also examined for its bark content, fibre dimension,• cell wall thickness, lumen diameter and density. The average bark content was 19.3-., per cent by volume and 12.6 per cent by weight. The average fibre length (1) was 2.22 mm; diameter (el) 31 microns, lumen diameter (t) 29.6 microns and cell wall thickness (w) was 6 microns. The average density of the wood work was 480 kg per cubic metre. The Runkle's coefficient (2w1t) was 0.405 which is less than 1, therefore this species was considered for evaluation. All the results are comparable with other softwoods reported in the literature. Pinus carihaea is of low ash (0.6 %) and acetyl content. (1.1 To), i t is of an average ho/oce//u/ose(66.8 /0) pentosan contents 81:32.10) and slightly higher extractive contents (7.5 50). Generally pine species have higher extractive content (3-10 50). Summation may be accounted for the sum of all individual components. The chemical constitutents considered are holocellulose, lignin, extractives, ash and acetyl content. The, sum of these constituents is 102.5 per cent, which is close to 100 per cent. The total of components in the range of 95-102 per cent is not uncommon. Elemental analysis of Pinus caribaea was carried out by combustion method. The ultimate analysis of wood consists of carbon 49.8 per cent, hydrogen 6.1 per cent and oxygen 43.3 per cent which is also comparable to the ultimate analysis of other pine species. ISOLATION OF HEMICELLULOSE For the study- of hemicellulose of Pinus caribaealwood meal was converted into holocellulose by reaction of sodium chlorite and acetic acid at 70°C and then holocellulose was treated with potassium hydroxide and boric acid (24 + 4 %) to prepare hemicellulose. Crude hemicellulose was purified by making its copper complex. The yield of holocellulose and hemicellulose was 66.8 per cent and 20.56 per cent respectively on the basis of o.d. wood. Holocellulose was examined for its ash content'(1.10 %) pentosan content (11.75 50), acetyl value (0.72 %) and alpha - cellulose (72.06 50) etc