A series of sulfonated cationic resins have been prepared and characterized from Egyptian bagasse pith wastes (as a source of cheaper and renewable material) with mcresol and paraformaldehyde as a crosslinking agent. Reaction conditions for the preparation are presented and properties of the synthesized sulfonated bagasse pithm-cresol-formaldehyde resins are described and compared with resin not containing bagasse pith. The synthesized resins are stable in water, dilute mineral acids (1 M), organic solvents, and to thermal treatment. The resins having a cation exchange capacity up to 2.91 meq g-' of dry resin, are being introduced as new exchangers. The synthesized resins are used in the study of the possible separation of some bivalent cations. ZUSAMMENFASSUNG:Eine Reihe sulfonierter kationischer m-Kresol-Paraformaldehyd-Harze wurden aus dem Mark agyptischer Bagasse hergestellt. Reaktionsbedingungen werden angegeben, und die Eigenschaften der hergestellten Bagassemark/m-Kresol/Formaldehyd-Harze werden mit denen von Harzen ohne Bagassemark verglichen. Die synthetisierten Polymere sind stabil in Wasser, verdunnten Mineralsauren (1 M) und organischen Liisungsmitteln sowie gegenuber thermischer Behandlung. Die Harze besitzen Kationenaustauscherkapazitaten von bis zu 2,91 meq/g (bezogen auf trockenes Harz) und werden als Austauschermaterialien fur eine mdgliche Trennung zweiwertiger Kationen getestet.

I n order to investigate the chemical constitution of bagasse pith-phenol polycondensate resin, different resins were prepared by condensation of phenol with compounds that may be produced during the acid hydrolysis of bagasse pith and with different constituents of bagasse pith. The optimum conditions for thin layer chromatographic separation of these polycondensate resins were determined. The proposed chemical structure and the pattern of chemical reactions were discussed on the bases of elemental analysis, TLC and UV spectroscopic studies. Zur Struktur von Polykondensationsharzen aus agyptischem Bagassemark und Phenol. Teil I . Elementaranalyse und kombinierte Dunnschichtchromatographie und U V-SpektroskopieUm die chemische Konstitution von Polykondensationsharzen aus Bagassemark und Phenol zu untersuchen, wurden verschiedene Kondensationsprodukte auf Basis von Phenol und Verbindungen, die bei der Saurehydrolyse von Bagassemark entstehen oder Bestandteile des Bagassemarks sind, hergestellt. Die optimalen Bedingungen fur die Trennung dieser Polykondensationsharze durch Dunnschichtchromatographie wurden ermittelt. Die angenommene chemische Struktur und das chemische Reaktionsschema werden an Hand der Ergebnisse der Elementaranalyse, der Dunnschichtchromatographie und der UV-Spektren diskutiert. 0 cmpyicmype nommonaencaquonnb&x C~O A u3 ezunemctcoti Bazaccu u $enona. Vacmb I . 3ne.wenrnapntaati anaaua u icoa6unayu~ monicocaotirsoti xpoaamozpa$uu c YO-cnenmpoctconueti C qenbm Hccxegosamis xmmecKoro cTpoeHm nonmoHgeHcaqHoHHbIx CMOJI Ha 6araccb1 M GeHona HaroToBnema 06pa3ymupxc~ n p~ ee m~p o n m e . Onpenenem OnTmamHbIe ~C J I O B H R p a 3 g e n e~u~ BTHX nonmoHneHcaquoHHMx CMOJI nyTeM TOHKOCJIO€~HO~~ xpoMaTorpa@mi. HpennosaraeMaH xuMuqecKax cTpymypa H cxeMa xnMmecKHx peaKqa# 06cym~am~cx Ha ocHnBe p e 3 y n b~a~o~ aneveHTapHoro aHamma, T O H K O C~O~~A O~~ xpoMaTorpa@m H YQ-pa3JIWIHbIe IIpOjQ'KTbI IIOJIHKOHAeHCaqAH @?HOJIa H COeAHHeHHfi, HBJIHIOLIWXCFI COCTaBHOl 'IaCTbIO 6araccb1 HJIH CneKTpOCKOnMH. SAAD, SAYYAH e t al.: Some aspects on the constitution of egyptian bagasse pith-phenol polycondensate resins. I Actr Polyrneria 39 (1988) Nr. 10 569 3. Results and discussion 3.1. Chemical structure of the resins

Different types of moulded shapes were prepared from Egyptian corncobs‐bisphenol polycondensate resins and aluminium powder. Modifications of the produced resin with phenol‐formaldehyde, naphthalene‐formaldehyde, and anthracene‐formaldehyde, were performed. The electrical conductivity of the samples increases with the increase of temperature and aluminium concent. All samples reveal semiconducting behaviour.

Unbleached kraft bagasse pulp was subjected to beating in Jokro beater for different time intervals. Beating caused minor chemical changes mainly a slight increase of DP, crystallinity and resistivity to acid hydrolysis. Fiber fractionation by weight and by number indicated that the most pronounced action of beating is the cutting of the long fibers and fibers of medium length causing an increase in the quantity of short fibers. The tear factor started to decrease very early in the beating cycle, while the other mechanical properties increased by beating but with different rates.Bewertung von ägyptischem ungebleichten Bagasse-Kraft-Zellstoff. Teil I: Wirkung der Mahlung auf die chemischen und mechanischen Eigenschaften ZusammenfassungUngebleichter Bagasse-Kraft-Zellstoff wurde in der Jokro-Mühle verschieden lange gemahlen. Durch die Mahlung werden die chemischen Eigenschaften kaum verändert, jedoch steigt der DP leicht an, ebenso die Kristallinität und die Resistenz gegen Säurehydrolyse. Gewichtsmäßige und zahlenmäßige Faserfraktionierung zeigen, daß die langen und mittellangen Fasern gekürzt werden, so daß die kurzen Fasern zunehmen. Schon im frühen Stadium der Mahlung nimmt die Fortreißfestigkeit ab, während die anderen mechanischen Eigenschaften sich durch den Mahlprozeß verbessern. IntroductionBeating refers to über Separation, über cutting and also fibrillation of fibers. The effect of beating is of fundamental importance in determining the paper making qualities of a given pulp. Generally, beating is primarily a mechanical process resulting in physical changes in fibrous structure and colloidal nature of the pulp (Casey 1960).Gurr an et al. (1930) found that in the case of Sulfate pulp, the i % alkali solubility was increased f rom 4.5 to 5.8% on beating for 6 hours, but this, too they attributed to a slight increase in reactive surface. Kress and Bialkowsky (1931) found that alpha cellulose content, copper number, and alkali solubility all remain practically constant during the beating of an unbleached Mitscherlich sulfite pulp, whereas the cupperammonium viscosity decreases and the ease of hydrolysis of the fibers in acid increases. The increase in hydrolysis number and decrease in cupperammonium viscosity are probably physical rather than chemical effect resulting from an increase in surface activity.Goldsmith and Higgins (1954) studied the effect of fiber length on the mechanical properties of paper. A well beaten eucalypt kraft pulp was fractionated to 4 fractions. A rapid fall of folding endurance was noted in going from the finest to the coarsest fraction. The fine fraction evidently act äs bonding materials. Al-

SYNOPSISThe article is concerned with a simple method for preparing cationic resins from polycondensation of Egyptian bagasse pith (as a source of cheap and renewable material) with phenol and paraformaldehyde as a cross-linking agent. Optimum principal reaction conditions of the preparation and properties are determined and compared with resin without bagasse pith content. The synthesized resins are stable in water, organic solvents, thermal treatment, and mineral acids (1M). The samples having a cation exchange capacity up to I NTRO DUCTIONBagasse pith is generally used as a furnace fuel of sugar mills' and for production of furfural.' The synthesis of resins from wood, lignin, and other cellulosic materials have been studied, '-' especially for the synthesis of polycondensate bagasse pith phenolic re~ins.6'~ Many ion exchangers owe their origin to petroleum products and there is a continual increase in their cost. Attempts have been made in earlier studies8-" to preparing cheaper cationic resins from natural products. The aim of the present work is to determine the optimum conditions of preparation and properties of sulfonated cationic exchangers from Egyptian plant by-products of bagasse pith, to study the selectivity coefficients of Li+-Na+ exchanges, and to find the optimum conditions for using cationic resins for the separation of Li+ from Na+ ions. The selectivity coefficients ( K , ) of the general ion-exchange reaction of Li& + NaR C LiR + Na&