SciELO - Scientific Electronic Library Online

 
vol.47 número3CONCENTRATIONS OG NI AND CO IN CROP PLANTS CULTIVATED IN NORTHERN CHILE índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Boletín de la Sociedad Chilena de Química

versión impresa ISSN 0366-1644

Resumen

TAPIA, C. et al. EFFECT OF THE REACTION CONDITIONS OVER THE YIELD AND PROPERTIES OF METHYLCELLULOSE OBTAINED FROM PINUS RADIATA KRAFT BLEACHED CELLULOSE. Bol. Soc. Chil. Quím. [online]. 2002, vol.47, n.3, pp. 289-297. ISSN 0366-1644.  http://dx.doi.org/10.4067/S0366-16442002000300013.

Kraft bleached cellulose from Pinus radiata was submitted to methylation reactions in heterogeneous media. After activation with 29% (w/w) NaOH solution, methylation reactions were carried out both with dimethyl sulfate (DMS) and methyl iodide (MI). The effects of the pressing ratio, reaction time and type of methylation agent were studied. The better yields were obtained with dimethylsulphate and the pressing ratio and reaction time were not signficant over the yield. Methylcellulose (MC) of high degree of substitution was extracted with water and the MC of low degree of substitution was extracted with 8%w/w NaOH. Some of the MCs obtained were characterized by viscosity average molecular weight, thermal behavior, degree of substitution, steady shear solution behavior. The MC water extracted obtained under certain reaction conditions showed similar behavior that commercial MC

Palabras llave : Methycellulose; Cellulose reactions; Solution properties; Thermogravimetry; Morphology.

        · resumen en Español     · texto en Inglés