INVESTIGADORES
ALVAREZ Vera Alejandra
congresos y reuniones científicas
Título:
Chemical treatment of cotton-cellulose fibers and their improvement of their compatibility with polycaprolactone
Autor/es:
LEANDRO LUDUEÑA; MIRIAN CASCO; VERA ALVAREZ; ANALÍA VÁZQUEZ
Lugar:
Salvador - Bahía
Reunión:
Congreso; INTERNATIONAL CONGRESS ON NATURAL FIBRES 2009; 2009
Resumen:
In this work, several surface treatments were carried out on cellulose fibers. They were: alkaline-treatments
(5, 10, 15 and 20 wt.% of NaOH and 10 wt.% of KOH); acetylation (treatment with glacial acetic acid for 1 or 2 hours
followed by catalyzed acetic anhydride) and esterification (treatments with stearic and lauric acids). The original and
modified celluloses were characterized by DSC (Differential Scanning Calorimetry), TGA (Thermogravimetric
Analysis), FTIR (Infrarred Spectroscopy), DRX (X-Ray Diffraction), SEM (Scanning Electron Microscopy), water
absorption test and contact angle measurements. The analysis confirmed the decrease on crystallinity for alkaline
treatment as a function of NaOH concentration together with the change from cellulose I to cellulose II, and the
increase on the polarity and water absorption. Acetylated fibers showed the higher change in crystallinity and a clear
decrease on polarity degree and water absorption. Esterification produced a slight increase on the crystallinity without
changing cellulose I whereas the water absorption decrease and the polarity decreased until zero. All the results
indicate that this last treatment took place at the surface. The most compatible fibers were used to prepare composites
with 15 wt.% of them (and the untreated ones as reference). Best properties were achieved with the 2 hours acetylated
fibers were a medium decrease on the polarity (good compatibility with the non polar matrix) and slight reduction on
the fiber aspect ratio was found.