Comparation of different environment-friendly anti-mildew agents on bamboo

Four kinds of environmental anti-mildew agents (boric acid/borax, 3-iodo-2-propynyl-butyl-carbamate (IPBC), sodium tetrafluoroborate/didecyl dimethyl ammonium chloride (NaBF4/DDAC), tebuconazole) were used to treat bamboo with different concentrations respectively. The optimal concentration of each anti-mildew agent and the comparison of the anti-mildew capacity were evaluated with Aspergillus niger, Trichoderma viride and Penicillium citrinum, respectively. The results showed that the optimal anti-mildew agent concentrations of boric acid/borax (F1), IPBC (F2), NaBF4/DDAC (F3) and tebuconazole (F4) were 3.0%, 1.5%, 0.5% and 0.4%, respectively, and the average control efficacy of the three test molds was 73.15%, 92.03%, 88.43% and 98.67%, respectively. The order of anti-mildew capability of these four anti-mildew agents with their optimal concentrations was F4 > F2 > F3 > F1.

Effects of differrent boron-based flame retardants on the combustibility of bamboo filaments

In this study, eight types of boron-based flame retardants were performed to evaluate the effects of different boron components on the combustibility of the bamboo filaments. Disodium octaborate tetrahydrate, boric acid/borax, and nano-ZnBO4 were used as the active flame retardant components. Besides, other inorganic flame retardants including nano-SiO2 and ammonium polyphosphate (APP) were also introduced in order to increase the flame retardant of these boron-based components. The combustibility of the bamboo filaments treated with different flame retardants were evaluated by cone calorimeter analysis. The results showed that the flame retardants including the heat release and smoke release resistance of the bamboo filaments with different boron-based components and nano-SiO2 or APP, could be significantly improved, especially, in the samples treated with the compound flame retardant composed of boric acid, borax and nano-SiO2, which was attributed to the synergistic effect of these flame retardant components.

Effect of different pre-treatments on the permeability of glue-laminated bamboo

In this study, hydrothermal treatments (duration: 2 h, 5 h, 8 h; temperature: 60°C, 80°C, 100°C), ultrasonic treatments (duration: 60 min, 90 min, 120 min; temperature: 40°C, 50°C, 60°C; ultrasonic power: 400 W, 600 W, 800 W) and freeze-drying treatments (vacuum degree: 0.05 mbar, 0.1 mbar, 0.5 mbar, 1.0 mbar, 1.7 mbar) were performed respectively to improve the permeability of glue-laminated bamboo. The effects of different pre-treatments on the permeability were compared according to the water absorption test and the mercury intrusion porosimetry test. The microstructure change of the samples was observed by scanning electron microscope (SEM). The results showed that freeze-drying treatment was an effective way to increase the permeability of the samples, in which the water absorption rate can be increased by 47%, and the porosity can be increased by 10% at 0.5 mbar vacuum. From SEM analysis, some small holes appeared in the cell wall of the freeze-dried samples, because he free water inside the samples was changed into ice, and the volume became larger, and the pore diameter of the bamboo was enlarged.