Preparation Of Microfibrillated Cellulose From Wood Puple And Its Application In UF Resin

This paper research a new type of cellulose morphology-microfbrillated cellulose(MFC),which could be extracted from wood pulp by mechanical method.Different pretreatmentmethods were used to compare the crystal structural and thermal stability of MFC.We alsoinvestigate the reinforcement of Microfbrillated cellulose modified UF resins. It would bebeneficial to prepare high-permormance composites reinforced with MFC.By changing the NaOH concentration and urea concentration,a series NaOH/urea aqueoussolutions were applied to pretreat wood pulp.As a result,5%NaOH/10%urea aqueous solutionpretreat MFC suspension was found to be a relatively stable suspension,which is more stable thanMFC pretreated by bio-ferment method.XRD result reveals that5%NaOH/10%urea aqueoussolution pretreated MFC was partly converted to celluloseⅡ, MFC pretreated by bio-fermentmethod was by celluloseⅠ by contrast,which is due to partly mercerization of cellulose.Thermogravimetric analysis suggest that MFC pretreated by bio-ferment method is more stablethan5%NaOH/10%urea aqueous solution pretreated MFC.Non-isothermal kinetics of MFCs were studied by DSC method,and their kinetic equationwere established.This research investigate the reinforcement of Microfbrillated cellulose modified UFresins.Differential scanning calorimetry was applied to investigate the curing behavior ofurea–formaldehyde (UF) resins reinforced with Microfbrillated cellulose（MFC）as affected by theMFC content. The thermal stability of UF resins was investigated by thermogravimetricanalysis.The TGA results reveal that the complexes had higher thermal-resistance propertiescompared to the common urea–formaldehyde resin. The dynamic mechanical behavior of thecomposites has been studied. The storage modulus and glass transition temperature of the polymeris increased by the incorporation of MFC. An increase of the adhesive bonds up to29%wasobserved when adding MFC to UF resin.