Viscoelastic evaluation of effects of fiber size and composition on cellulose‐polypropylene composite of high filler content

Abstract

The dispersion of filler in resin is an important factor which determines the mobility of a compound in a molder and also the mechanical properties of molded products in wood/plastic composite, especially with high wood filler content. In this report, the dispersion of components in the melt‐mixture of a compound in response to the size of cellulose filler and resin content was examined for compounds with a high content of cellulose in polypropylene by the evaluation of viscoelasticity using a cone rheometer, and the following conclusions were obtained: (1) The viscoelasticity measured by a cone rheometer was dependent on the dispersion state of the compound, and it was confirmed that the presented evaluation method of viscoelasticity affords information relevant to the dispersion state of filler in a compound; (2) On the basis of the viscoelastic evaluation of compounds with different resin contents, a model for the distribution of cellulose and resin is proposed in terms of the tangle of fibers; (3) Viscoelastic analysis showed that cellulose size has an influence on the tangle of fibers; (4) The results of viscoelasticity and mechanical properties of molded products suggested that an important factor determining the tangle of fibers is the average aspect ratio. The proposed analysis of viscoelasticity presents a simple technique for estimating the dispersion state of a compound with high filler content, which is hardly possible by conventional fluid evaluation methods. POLYM. ENG. SCI., 48:168–176, 2008. © 2007 Society of Plastics Engineers

Reinforcement of fiberboard containing lingo-cellulose nanofiber made from wood fibers

“…On the other hand, for hardwood fiberboards, the bending properties for LCNFmixed fiberboard for 1.00 g/cm 3 -density board were higher than those for the control fiberboard. In general, the quality of composite properties mixed with smaller size particles was not improved [27]. Nevertheless, in this study, the properties of fiberboards made with LCNF were much improved compared to wood fiber only.…”

Reinforcement of wood flour board containing ligno-cellulose nanofiber made from recycled wood

“…Particle size of the LCNF for 200 rpm/32 h was 1/20 that of untreated wood flour (Table 1). In general, the quality of composite properties mixed with smaller size particles was not improved [20]. Nevertheless, in this study the The board densities were almost the same as those shown in Table 2, indicating that the void ratios in the test samples were nearly identical.…”

Binding effect of cellulose nanofibers in wood flour board

“…The highest moduli were found for the board having a WF:CNF of 90:10, which was considered the optimal composition. Increasing the CNF content above 20% caused the moduli to decrease, which was attributable to flocculation of the CNF [6], which likely became more important as pulverization progressed. The mixing condition chosen for this part of the study (i.e., 250 rpm/2 h) was just sufficient to generate a binding effect by the CNF.…”