Procjena mogućnosti upotrebe strnjike obične pšenice (Triticum aestivum L.) za proizvodnju celuloze i papira

The aim of the study was to determine the properties of pulp and paper produced from wheat stubble (Triticum aestivum L.), using soda-oxygen-sodium borohydride (NaBH4) cooking method. Whole wheat straw (Triticum aestivum L.) was also used for comparison with stubbles. The morphological and chemical properties of the raw materials were investigated. The results showed that stubble had high holocellulose, cellulose, and alpha-cellulose contents and low lignin content. Fiber length, fiber width, lumen diameter, and cell wall thickness were measured in order to determine suitability of the fibers for pulp and paper production. The values were used to calculate fiber parameters. The effects of these parameters on paper strength were also discussed. The effect of NaBH4 on the yield and chemical, physical, and optical properties of pulp and paper were investigated. The addition of NaBH4 increased pulp yield by 4.1 %, and improved the physical and optical properties of the pulp. The physical and optical properties of the stubble pulp were better than those of whole wheat straw pulp. It was concluded that these characteristics demonstrate the suitability of wheat stubbles for pulp and paper production.Cilj istraživanja bio je odrediti svojstva celuloze i papira proizvedenih od strnjike pšenice (Triticum aestivum L.) metodom kuhanja s dodatkom soda-kisik-natrijborohidrida (NaBH4). Radi usporedbe, određena su i svojstva celuloze i papira izrađenih od slame pšenice (Triticum aestivum L.). Određena su i analizirana morfološka i kemijska svojstva istraživanih sirovina. Rezultati istraživanja pokazali su da strnjika pšenice ima visok sadržaj holoceluloze, celuloze i α-celuloze te nizak sadržaj lignina. Radi utvrđivanja prikladnosti vlakanaca za proizvodnju celuloze i papira, izmjereni su duljina vlakanaca, širina vlakanaca, promjer pora i debljina stanične stijenke. Dobivene su vrijednosti iskorištene za izračun parametara vlakanaca. Također je analiziran utjecaj tih parametara na čvrstoću papira. Istražen je utjecaj NaBH4 na prinos celuloze te na kemijska, fizikalna i optička svojstva celuloze i papira. Dodatak NaBH4 povećao je prinos celuloze za 4,1 % i poboljšao fi zikalna i optička svojstva celuloze. Fizikalna i optička svojstva celuloze izrađene od strnjike pšenice bila su bolja od svojstava celuloze proizvedene od pšenične slame. Zaključeno je da svojstva celuloze proizvedene od strnjike pšenice potvrđuju pogodnost te sirovine za proizvodnju celuloze i papira

Viscous gel-forming gums (VGUMS) of cereal grains: Rheology and viscosity-based enzyme activity quantification

The rheology of viscous-gel forming gums (VGUMS) extracted from cereal grains (barley, oat, wheat) by using alkaline or acid solutions was investigated in this study. Molecular weight (Mw), viscosity average molecular weight (Mv), overlap concentration (C*) and intrinsic viscosity [η] of VGUMS were predicted by viscosity calibration assays using a reference sample with known Mw. The Mw, Mv, C* and [η] were significantly (P < 0.05) affected by temperature, solvent type, dilution rate and grain type, but all the values were within acceptable limits of previously reported values. The use of Mark-Houwink equation was very powerful and successful to predict Mw(s) of VGUMS from viscosity measurements. The present results indicated that the C* should be considered in the viscosity based enzyme activity quantification in order to avoid a systematic error in the measurement caused by the effect of volumetrically diluted substrate concentration in the solvent. Furthermore, the cellulase activity of a reference enzyme and unknown enzyme sample was well predicted by this viscosity-based quantification method, with acceptable precision and recovery rate. It can be concluded that the rheology of both acidic and alkaline VGUMS provide important information on grain quality and quantification of enzyme activity, which are useful for the industry

Investigation of Isatis Tinctoria and Isatis Buschiana Stalks as Raw Materials for Pulp and Paper Production

Isatis tinctoria and Isatis buschiana were evaluated as raw materials for pulp and paper production. Chemical composition and morphological aspects of Isatis stalks were determined. Lignin contents of I. tinctoria and I. buschiana were 23.9 % and 19.9 %, respectively. alfa-cellulose ratio was found to be 48.5 % in I. tinctoria and 32.9 % in I. buschiana. Fiber length, fiber diameter, lumen diameter and cell wall thickness were measured and the obtained data was used to calculate felting rate, elasticity coeffi cient, rigidity coefficient, runkel index and F factor. Handsheets were produced from Isatis stalks, and physical and optical properties were determined. Breaking length, tear index and burst index values were higher for the beaten pulp than for unbeaten pulp, while brightness and whiteness values were higher in unbeaten pulp.U radu su istražene mogućnosti upotrebe stabljike biljaka Isatis tinctoria i Isatis buschiana kao sirovine za proizvodnju celuloze i papira. Određeni su kemijski sastav i morfološka svojstva stabljike. Sadržaj lignina u stabljici I. tinctoria bio je 23,9 %, a u stabljici I. buschiana 19,9 %. U stabljici I. tinctoria utvrđen je udjel alfa-celuloze od 48,5 %, a u stabljici I. buschiana taj je postotak iznosio 32,9 %. Izmjereni su duljina i promjer vlakanaca, promjer pore i debljina stanične stijenke, a dobiveni su podaci iskorišteni za izračunavanje brzine fi lcanja, koefi cijenta elastičnosti, koefi cijenta krutosti, Runkelova indeksa i F-faktora. Od stabljika biljaka Isatis tinctoria i Isatis buschiana proizvedeni su listovi papira kojima su zatim određena fizikalna i optička svojstva. Utvrđeno je da je veće vrijednosti duljine lomljenja, indeksa cijepanja i indeksa pucanja imao papir od mljevene celuloze nego papir od nemljevene celuloze, dok je papir od nemljevene celuloze imao veće vrijednosti sjajnosti i bjeline

Istraživanje mogućnosti upotrebe stabljika biljki Isatis tinctoria i Isatis buschiana kao sirovine za proizvodnju celuloze i papira

Isatis tinctoria and Isatis buschiana were evaluated as raw materials for pulp and paper production. Chemical composition and morphological aspects of Isatis stalks were determined. Lignin contents of I. tinctoria and I. buschiana were 23.9 % and 19.9 %, respectively. alfa-cellulose ratio was found to be 48.5 % in I. tinctoria and 32.9 % in I. buschiana. Fiber length, fiber diameter, lumen diameter and cell wall thickness were measured and the obtained data was used to calculate felting rate, elasticity coeffi cient, rigidity coefficient, runkel index and F factor. Handsheets were produced from Isatis stalks, and physical and optical properties were determined. Breaking length, tear index and burst index values were higher for the beaten pulp than for unbeaten pulp, while brightness and whiteness values were higher in unbeaten pulp.U radu su istražene mogućnosti upotrebe stabljike biljaka Isatis tinctoria i Isatis buschiana kao sirovine za proizvodnju celuloze i papira. Određeni su kemijski sastav i morfološka svojstva stabljike. Sadržaj lignina u stabljici I. tinctoria bio je 23,9 %, a u stabljici I. buschiana 19,9 %. U stabljici I. tinctoria utvrđen je udjel alfa-celuloze od 48,5 %, a u stabljici I. buschiana taj je postotak iznosio 32,9 %. Izmjereni su duljina i promjer vlakanaca, promjer pore i debljina stanične stijenke, a dobiveni su podaci iskorišteni za izračunavanje brzine fi lcanja, koefi cijenta elastičnosti, koefi cijenta krutosti, Runkelova indeksa i F-faktora. Od stabljika biljaka Isatis tinctoria i Isatis buschiana proizvedeni su listovi papira kojima su zatim određena fizikalna i optička svojstva. Utvrđeno je da je veće vrijednosti duljine lomljenja, indeksa cijepanja i indeksa pucanja imao papir od mljevene celuloze nego papir od nemljevene celuloze, dok je papir od nemljevene celuloze imao veće vrijednosti sjajnosti i bjeline