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The crystallization behaviors of acetylated bamboo fiber (BF)/polypropylene (PP) composites were assessed using differential scanning calorimetry (DSC) through isothermal crystallization. The transcrystalline (TC) morphologies of composites were observed through polarized optical microscopy (POM), and their surface free energies were calculated based on Hoffman‒Lauritzen theory. Isothermal DSC thermograms demonstrated that acetylated BF with higher weight percentage gains (WPGs, ~ 19%) exhibited a decreased crystallization rate of the PP matrix. POM images indicated that BF as a nucleation agent induced the TC layer on fiber–PP matrix interfaces. However, when WPG reached 19%, the TC layer was not observed on the BF surface and crystal growth was principally observed in the PP matrix bulk. Based on Hoffman‒Lauritzen theory, the folding-surface free energy (σe) and the work of chain folding (q) for acetylated BF/PP composites were estimated to be higher than those for PP composites with unmodified BF. These results indicate that BFs with different WPGs could affect the crystallization behavior of the PP matrix by inducing or hindering TC on BF–PP matrix interfaces. [ABSTRACT FROM AUTHOR]

This study investigated the effect of heat-treated veneers on the physicomechanical properties and extended creep behavior of plywood using the stepped isostress method (SSM). The results revealed that the mechanical properties of plywood composed of fully and partially heat-treated veneers were not significantly different from those of the untreated plywood. In addition, the SSM was successfully applied to constructing the plywood creep master curves. The creep resistance of the heat-treated plywood surpassed that of the untreated plywood, especially the 5T200 plywood, which also exhibited the lowest compliance values of 0.13, 0.14, and 0.15 GPa−1 at 5, 10, and 20 years, respectively. [ABSTRACT FROM AUTHOR]

In this study, makino bamboo (Phyllostachys makinoi) fibers were acetylated with different solution ratios of acetic anhydride/dimethylformamide using a liquid phase reaction. This reaction resulted in the production of acetylated bamboo fibers (BFs) with the following weight percent gains (WPGs): 2, 6, 9, 13, and 19%. The effects of the acetylation level on the thermal decomposition kinetics of bamboo fibers were evaluated by thermogravimetric analysis. The results revealed that as the acetylation level increased, both the onset and maximum decomposition temperatures increased. In addition, four model-free iso-conversional methods, the Friedman method, Flynn–Wall–Ozawa method, the Starink method, and the modified Coats–Redfern method, were used to determine the thermal decomposition kinetics. Accordingly, the activation energies of thermal decomposition with conversion rates ranging between 10% and 70% were 191–196, 190–191, 192–194, 182–186, 186–191, and 189–201 kJ/mol for unmodified BFs and acetylated BFs with WPGs of 2, 6, 9, 13, and 19%, respectively. There were no significant dependencies among them. Furthermore, the Avrami method was used to determine the reaction order of unmodified BFs (0.47), which was lower than those of acetylated BFs (0.55–0.74). [ABSTRACT FROM AUTHOR]

This study investigated the effectiveness of maleated polypropylene (MAPP) as a coupling agent for improving the physico-mechanical properties and creep resistances of wood‒polypropylene composites (WPCs). The results revealed that the composites with MAPP showed significantly decreased water absorption and thickness swelling, while the flexural properties and the wood screw holding strength increased as the MAPP content increased up to 3 wt%. Additionally, flexural creep tests were conducted at a series of elevated temperatures and stresses using the stepped isothermal method (SIM) and the stepped isostress method (SSM), respectively. The SSM-predicted creep compliance curves fit better with the experimental data than the SIM-predicted curves. On the other hand, the creep master curves for all of the WPCs were constructed from different SSM test conditions and were highly consistent with the long-term experimental creep data. The creep resistance values of the composites with MAPP were greater than those without MAPP, especially for the WPC with 5 wt% MAPP (WPCM5), due to the improvement in the interfacial compatibility between the wood fibers and PP matrix. Furthermore, according to the SSM-predicted creep behavior, the improvement in creep resistance (ICR) of WPCM5 reached 61% over a 20-year period compared to the WPC without MAPP. [ABSTRACT FROM AUTHOR]

A poly(lactic acid) (PLA)/polyamide 11 (PA11)/SiO2 composite was mixed from PLA, PA11, and nanosilica particles through twin-screw extrusion. The PLA/PA11/SiO2 composite was evaluated with tensile and Izod impact tests, light transmission and haze measurement, and isothermal and nonisothermal crystallization behavior determinations. The PLA/PA11/SiO2 (97.0/3.0) composite had approximately 10.8% less ultimate tensile strength than neat PLA, but it had greater ductility and approximately ninefold greater elongation at break. A dimple morphology was observed on the fractural surface of the PLA/PA11/SiO2 composite, indicating that the incorporation of PA11 and nanosilica particles increased the ductility of the PLA matrix. PLA with less than 3 wt% of PA11 and 0.5 phr of nanosilica particles had an Izod impact strength of 8.72 kJ/m2. PA11 and nanosilica particles effectively toughened this PLA polymer; they accelerated both isothermal and nonisothermal crystallization rates and increased the crystallinities of the resulting composites under isothermal and nonisothermal crystallization processes. [ABSTRACT FROM AUTHOR]

A series of hybrid materials composed of zirconia, silica, and thiazole dyes were synthesized from zirconium npropoxide (ZNP) and tetraethoxysilane (TEOS) using heteroaryl 2-amino-thiazole azo dyes, and prepared via the sol-gel process. The heterocyclic 2-amino-thiazole azo dyes underwent a hydrolysis-condensation reaction with an appropriate proportion of ZNP under a catalyst, using a constant ratio of vinyltriethoxysilane (VTES) and TEOS. The structures of these hybrid materials composed of zirconia/silica/thiazole dyes were characterized using Fourier transform infrared (FT-IR) analysis. The surface morphologies of the polyethylene terephthalate (PET) fabrics were evaluated using scanning electron microscopy (SEM). The SEM images demonstrated the uniform dyeing of the PET fabrics, which confirmed the reaction of the hybrid materials with the PET fabrics. The water contact angle, washing fastness, color uniformity, and warmth retention of the PET fabrics dyed with the hybrid materials composed of the zirconia/silica/thiazole dyes were evaluated. The evaluation results indicated that these fabrics offered enhanced warmth retention properties and good water repellency. [ABSTRACT FROM AUTHOR]

A hydrophilic copolymer, ethylene-vinyl alcohol (EVOH), was incorporated into the poly(lactic acid) (PLA) matrix to improve the barrier property of PLA through twin-screw extrusion rather than the typical coextrusion process. A chain extender, poly[(ethylene)-co-(methyl acrylate)-co-(glycidyl methacrylate)] (PEMG), was used to reduce the probability of the thermal degradation of PLA during melt compounding. Biaxial stretching was used to enhance the microstructure and barrier property of PLA-PEMG/EVOH films. Experimentally, PEMG considerably reduced the probability of the thermal degradation of the PLA-PEMG sample. Biaxial stretching increased the tensile strength and decreased the value of elongation at break of the PLA-PEMG/EVOH80 (PLA/EVOH 100/80) film. Because of the efficient blending of PLA/EVOH in the twin-screw extruder, the dispersion of EVOH in the PLA matrix revealed homogeneous dispersion with a domain size of 1-5 μm. EVOH effectively improved the water vapour transmission rate (WVTR) of PLA through melt blending. Blending PLA-PEMG with EVOH substantially decreased the WVTR from 250 cc-20 μm/m-day-atm for neat PLA to approximately 65 cc-20 μm/m-day-atm for the PLA-PEMG/EVOH80 film, a decrease of approximately 74 % compared with neat PLA. Moreover, the WVTR decreased further from 65 cc-20 μm/m-day-atm for the unstretched PLA-PEMG/EVOH80 film to 6.3 cc-20 μm/m-day-atm for the film stretched at a stretch ratio of 3.5 × 3.5 and at 100 %/s, a decrease of approximately 90 % compared with neat PLA. [ABSTRACT FROM AUTHOR]

In this work, an inorganic/organic hybrid material composed of tin dioxide, silica, and heteroaryl 2-aminothiazole was derived. Heteroaryl 2-aminothiazole, which acts as the coupling component, was synthesized based on a previously published method and coupled with p-nitroaniline, which is the diazonium component, to yield the heteroaryl thiazole azo dyes. Alternatively, tin dioxide/silica/thiazole dye hybrid materials were prepared by heating tetrahydrofuran solutions containing these thiazole dyes with various amounts of tin chloride and tetraethoxysilane to promote hydrolytic polycondensation via the sol-gel method. The structure of these hybrid tin dioxide/silica/thiazole dye materials was characterized by Fourier transform infrared (FT-IR) analysis. The uniform dyeing of the polyester fabric revealed by the scanning electron microscope images confirmed the reaction of the hybrid materials with the polyester fabrics. The results of the characterization of the warmth retention, color strength, water repellency, and air permeability of the polyester fabric dyed with the tin dioxide/silica/thiazole dye hybrid materials indicated that the sol-gel hybrid-material finishing agents significantly improve the properties of polyester fabric. [ABSTRACT FROM AUTHOR]

This work prepared poly (lactic acid) (PLA)/single-walled carbon nanotubes (SWCNTs) composites using a solution blend method, and investigated the influence of the physical properties of PLA/SWCNTs composites. In order to enhanced interfacial interactions between PLA and SWCNTs, the purified SWCNTs were given functionalisation treatments with a nitric acid/sulfuric acid mixture. These acid-treated SWCNTs (A-SWCNTs) were then grafted with 3-isocyanatopropyl triethoxysilane (A-SWCNTs-Si). When these functionalized SWCNTs were used to fill the PLA matrix, the fractured surface of composite does not present the pullout phenomenon. The dimensional stability obviously increased by a factor of approximately 72. The storage modulus was also significantly improved. The surface resistivity of the PLA/SWCNTs composites decreased from 1 × 10 to 2.22 × 10 Ω/cm. [ABSTRACT FROM AUTHOR]

This study produced poly (lactic acid) sheets using a biaxial stretching process, to investigate the effects of biaxial stretching on thermal properties, crystallinity, shrinkage and mechanical properties of PLA films. The results of differential scanning calorimetry show that the glass temperature peak of PLA films, which weakened after stretching. The cold crystallization peak of PLA films nearly disappeared at stretch ratios of 4 × 4 with a stretching rate above 50 %/s. The orientation and strain crystallization of PLA films were suppressed at stretching temperatures of approximately 100-110 °C. The shrinkage of PLA decreased proportionally to the stretch rate and inversely proportional to the stretching temperature, suggesting that the internal stresses frozen in the amorphous phase were an indication of a decrease in the crystallinity of the films, implying that PLA films would be best suited to low-shrinkage applications. The stress-strain of the PLA films increased considerably following the biaxial stretching process. In addition, PLA films exposed to hot water treatment show a slight decrease in stress values, probably attributable to a relaxation of the molecules, which have undergone orientation but failed to crystallize. [ABSTRACT FROM AUTHOR]

This research explores the dispersion pattern, curing behavior and intermolecular interaction of liquid silicone, polypropylene oxide-polyethylene oxide copolymer and clay composites. It analyzes the curing behavior of each component composite by means of the rigid-body pendulum rheometer, and then it is followed by the exploration of the intermolecular interaction with the dynamic mechanical analysis. Results show that the polymer chains of polypropylene oxide-polyethylene oxide copolymer expand clay gallery distance from 1.21 nm to 1.84 nm. Clay, after it has been organically modified (Oc), is added to silicone/polypropylene oxide-polyethylene oxide copolymer (SP) blends and its gallery spacing shortens from 2 nm to 1.7 nm. In the curing behavior of SP/clay composites, ammonium salt ions affect the cross-linking reaction of SP blends. Also, the curing time of Oc is shorter and the reacting rate is increased. Furthermore, clay, Oc and the SP have intermolecular interaction with each other. In addition, the unmodified clay in SP blend enhanced their mechanical and thermal properties. [ABSTRACT FROM AUTHOR]

Calocedrus formosana Florin is a softwood tree species with high economic value in Taiwan. Several bioactivities of the extracts of C. formosana have been reported; however, only one study focused on the anti-non-small-cell lung cancer cells' (anti-NSCLC) effect of C. formosana extract and its active phytocompound. In the present study, the anti-lung cancer effects of C. formosana leaf extract and its active derivative yatein were evaluated. The results revealed that the n-hexane fraction of the crude extract exhibited the highest cytotoxicity potential against two non-small-cell lung cancer (NSCLC) cell lines, namely A549 and CL1-5. Yatein, isolated from the n-hexane fraction, exhibited the highest cytotoxicity in the A549 and CL1-5 cells. In addition, the CL1-5 cells were more sensitive than the A549 cells after yatein treatment. Flow cytometry results revealed that yatein induced apoptosis in the two cell lines. Furthermore, expression of regulatory proteins related to apoptosis, such as caspase 3, caspase 8, caspase 9, and poly (ADP-ribose) polymerase (PARP), increased in the A549 and CL1-5 cells after yatein treatment. These findings provide insight into the in vitro anti-lung tumor efficacy of yatein, thus rendering this phytocompound a potential anticancer lead compound for NSCLC treatment. [ABSTRACT FROM AUTHOR]