Volume 9 Issue 3

Cellulose acetate (CA) was successfully synthesized by the acetylation of TCF cellulose pulp from oil palm empty fruit bunches (OPEFB) at room temperature, using acetic anhydride as the acetylating agent and acetic acid as the solvent in the presence of sulfuric acid/sodium bisulfate as catalysts. Degree of substitution (DS) was controlled by the variables of acetylation time and acetic anhydride to cellulose ratio, under the heterogeneous state. The product (CA) obtained was characterized through Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results indicate that the CA obtained has characteristics similar to commercial CA, and DS is significantly dependent on acetylation time and the acetic anhydride-to-cellulose ratio.

Aging means that a polymer material’s performance gradually deteriorates, with the loss of use value due to the comprehensive effect of internal and external factors. In this work, a starch-based aqueous polymer isocyanate (API) adhesive joint structure of crosslinking in bonding interface was investigated. The compression shear strength was recognized as a key evaluation index, and the hygrothermal aging experiment tests were accelerated to study the damage mode and failure mechanism of the glue joint structure. The results showed that the adhesive properties of fracture were ductile fracture, and with an increase of aging time, the damage mode of the bonding was transformed from a cohesion damage mode to a cohesion damage with interface damage mode. In the early stages of the aging tests, the effect of temperature on the compression shear strength was most important; however, with the increase of aging time, the effect of humidity became most important.

This work presents a techno-economic analysis of two modelled microcrystalline cellulose (MCC) production facilities, a stand-alone mill, and a mill integrated into a chemical pulp mill, with annual production levels of 30,000 tons/year. These results indicate that both options can be very profitable when the return on investment and the added value of the purchased chemical pulps are used as indicators. However, the integration of MCC production will yield about 19% greater net profit than the non-integrated alternative. Integration also reduces the economic risk of investment, since operation of the MCC plant can be halted for maintenance and chemical pulp can be produced in a normal manner.

This work presents a techno-economic analysis of two modelled microcrystalline cellulose (MCC) production facilities, a stand-alone mill, and a mill integrated into a chemical pulp mill, with annual production levels of 30,000 tons/year. These results indicate that both options can be very profitable when the return on investment and the added value of the purchased chemical pulps are used as indicators. However, the integration of MCC production will yield about 19% greater net profit than the non-integrated alternative. Integration also reduces the economic risk of investment, since operation of the MCC plant can be halted for maintenance and chemical pulp can be produced in a normal manner.

Furfuryl alcohol modification of wood is a well-known process for wood property enhancement. The present project focuses on veneer molding for high-value applications using the plasticizing effect of furfuryl alcohol. Adding maleic anhydride to furfuryl alcohol leads to an acid-catalyzed polymerization of furfuryl alcohol at elevated temperatures, fixing the shape of the veneer. In contrast to water or water vapor treatment, furfuryl alcohol-modified cell walls face a lower degree of shrinkage due to the polymer formation and possibly experience less drying-induced cracks. Earlier studies show a distinct influence of maleic anhydride on the curing of furfuryl alcohol. To determine the impact of different maleic anhydride contents on the polymer formation and the corresponding shrinkage of wood cell walls, microscopic studies were carried out on various maple microtome sections (Acer sp.), i.e., when dry, water-impregnated, after furfuryl alcohol impregnation, and after curing at elevated temperatures. At each state, the cell walls of 30 appointed early wood cells were determined by cell wall area measurements. The lowest shrinkage of impregnated samples was realized by using 10 wt% maleic anhydride in the impregnation solution and after 48 h soaking. Here, cell wall shrinkage could be reduced by approx. 42.6% compared to water-impregnation.

Wood samples of Cupressus arizonica, C. lusitanica, and C. sempervirens were evaluated for chemical, anatomical, and pulp characteristics as raw material for pulp production. Two 17-year-old trees per species were harvested, and wood samples were taken at a height of 2 m. Wood chips from Pinus pinaster (Portugal) and P. sylvestris (Finland) were used as references. C. arizonica differed from C. lusitanica and C. sempervirens with significantly lower (p < 0.05) tracheid diameter and wall thickness in the earlywood. The total extractives contents were 3.9%, 3.3%, and 2.5% for C. lusitanica, C. sempervirens, and C. arizonica, respectively, lower than the 5.1% for P. pinaster and 4.5% for P. sylvestris. Klason lignin content ranged from 33.0 to 35.6%, higher than the 28.0 to 28.7% for the pinewoods. The kraft pulp yields for C. arizonica, C. lusitanica, and C. sempervirens were 37.7%, 36.7%, and 38.7%, respectively, with kappa numbers of 32.0, 31.6, and 28.7, respectively; the yield values were 40.8% and 42.8%, with kappa numbers of 23.4 and 21.0, for P. pinaster and P. sylvestris, respectively. The cypress species are clearly different from pine in relation to wood pulping behavior. Among the cypress, C. sempervirens provided the best pulping results.

Cellulosic pulps were prepared from Stellera chamaejasme roots using soda, soda-anthraquinone (soda-AQ), and kraft pulping processes. S. chamaejasme is composed of 73.5% holocellulose, 39.7% α-cellulose, and 17.6% lignin, similar to wheat straw and other non-wood plant materials. The ethanol–benzene extractives content of 9.2% is higher than other non-woods. The conditions used for all pulping experiments were as follows: a liquid/solid ratio of 5:1; a time-to-maximum temperature of 100 min; a maximum temperature of 160 °C; and a time-at-maximum temperature of 50 min. The results showed that the pulp yield was 31.27 to 36.83%, the kappa number was 16.32 to 19.42, and the pulps’ intrinsic viscosity was 854 to 976 mL/g. Tear index, tensile index, burst index, and brightness of the papers made from the above unbleached pulps were 12.60 to 13.62 mN•m2/g, 20.57 to 22.56 mN/g, 2.16 to 2.38 kPa•m2/g, and 15.3 to 18.3%, respectively.

Manufacturing panels from Tetra Pak® (TP) packaging material might be an alternative to conventional wood-based panels. This study evaluated some chemical and physical properties as well as biological, weathering, and fire performance of panels with and without zinc borate (ZnB) by using shredded TP packaging cartons. Such packaging material, a worldwide well-known multilayer beverage packaging system, is composed of cellulose, low-density polyethylene (LDPE), and aluminum (Al). Panels produced from waste TP packaging material were also examined by FT-IR to understand the fungal deterioration and extent of degradation after accelerated weathering. Before FT-IR investigations, panel specimens were ground under nitrogen atmosphere due to non-uniformity of the composite material. The FT-IR results showed that fungal degradation occurred in the natural polymer of the panel matrix. Although the natural polymer is mostly composed of cellulose, there were also small amounts of polyoses and lignin. It was seen that especially polyose and lignin bands in FT-IR spectra were affected more than cellulose bands by fungal attack. No changes were observed by the fungi in the plastic component (LDPE) of the matrix; however, LDPE seemed more sensitive to weathering than cellulose. Incorporation of ZnB at loading level of 1% (w/w) did not contribute fire performance of the panels when compared to control panel specimens, while a loading level of 10% improved fire performance considering test parameters such as mass loss, ignition time and peak heat release rate.

This paper reports the bending strength and maximum deflection after plasticizing beech wood by microwave heating. Previous work by the authors confirmed that microwave heating resulted in plasticizing of beech wood, which greatly affected its deformation when loaded by compression. This work complements the overall analysis of the behavior of microwave-plasticized wood during its bending. Bending strength and maximum deflection were investigated on beech samples immediately after plasticizing by microwave heating. Static bending test with three-point flexural test was used. While plasticizing time and moisture content had an important influence on the bending strength, the device power had no appreciable effect. Plasticizing time had a significant influence on the maximum deflection, while the moisture content and device power had no substantial influence.

The effects of the plasticizer 1,2-cyclohexane dicarboxylic acid diisononyl ester (Hexamoll® DINCH) on the thermal stability and degradation of poly (lactic acid) were investigated and compared with tributyl citrate and montmorillonite. A series of poly (lactic acid) composites were prepared via melt blending before being hot pressed into 0.3 mm films. Along with the increase of the content of MMT, the agglomeration degree rise and the MMT content for this study was determined. The addition of Hexamoll® DINCH could efficiently decrease the Tg of PLA and improve the crystallinity of poly (lactic acid) composites. The addition of DINCH or TBC could deteriorate the thermal stability of PLA composites. The addition of montmorillonite could improve the thermal stability of PLA/TBC and PLA/DINCH composites. The kinetic parameters including activation energy of decomposition (E), reaction order (n), and pre-exponential factor (lnA) of PLA/DINCH/MMT composites are 180.2 kJ/mol, 0.863, and 36.8, respectively by using Freeman-Carroll method.