Pine flour

Cellulose hber, obviously, increases viscosity of plastic hot melt. Furthermore, fiber from different species affects viscosity differently, even at the same particle size. For example, pine, juniper, and salt cedar (particle size 40-60 mesh), each at 50% amount w/w in HDPE, resulted in melt flow index (MFI) of 0.2,0.6, and 1.6, respectively. In other words, pine flour increased viscosity the most. Viscosity continued to increase with smaller wood flour particles (Table 3.12). 

It can be conjectured why pine-derived fiber as a filler produced much stronger (by 19%) and much stiffer (by 36%) board compared to that filled with maple-derived filler, and why the maple flour-filled WPC became so week and flexible after the freeze-thaw cycles compared to the pine- flour-filled board however, we do not have clear, direct, examined, and verified answers. 

Experiments for fimgal degradation of pine flour were carried out by following an established procedure for fungal degradation of pulp (5). Pondarosa pine sapwood flour (30 mesh) was extracted with acetone/water (v/v, 9/1) and dried under vacuum. The moisture content was determined as 9.8 %. A mixture of wood flour (9.07 g oven-dried) and de-ionized water (10 mL) was autoclaved in 250 mL Erlenmeyer flask at 121 °C for 1 h. The autoclaved wood flour was inoculated with the P. cinnabarinus spore suspension (5 mL), and the moisture content of the wood flour adjusted to 80% with sterilized water. The culture was then incubated at 30 °C for pre-determined times. Twelve replicates were carried out for each cultivation time. 

Table IIL The Contents of Various Functional Groups (mmol/g Lignin) after a Three-month Degradation of Pine Flour by Three Fungi as Determined by NMR Techniques ...

More recently [22], a poly-(aminoamide-epichlorohydrin)/stearic anhydride compatibilizer system was developed to optimize the interface between pine flour and polyethylene in the corresponding composites. FTIR spectra showed that the compatibilizer had indeed been grafted to the wood particles and the decrease in water uptake by the composite corroborated the interest in using this novel system. 

Figure 15.11 Thermogravimetric analysis of pine flour and wood cellulose. 15.3.6...

Figure 15.11 shows a thermogravimetric analysis of pine flour and wood cellulose. Due to its low thermal stability, wood flour is usually used as filler only in plastics that are processed at low temperatures, lower than about 200 °C. Above these temperatures the cell wall polymers begin to decompose. High-purity cellulose pulps, where nearly all of the less thermally stable lignin and hemicelluloses have been removed, have recently been investigated for use in plastic matrices such as nylon that are processed at higher temperatures than most commodity thermoplastics [27]. 

Fredrick Walton invents finoleum, comprised of linseed oil, pigments, pine rosin, and pine flour... 

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