Water resistance of rare earth fluorescent bamboo plastic composites modified with hydrogen silicone oil
To improve the water resistance of rare earth fluorescent bamboo plastic composites and broaden the scope of application, the surface of bamboo powder and strontium aluminate phosphor were modified by hydrogen-containing silicone oil. Rare earth fluorescent bamboo plastic composites modified with hydrogen-containing silicone oil were manufactured by melt blending and injection molding process. In the composites, the contents of bamboo powder and strontium aluminate phosphor were both 13.89%. The effects of hydrogen-containing silicone oil on the contact angle, water absorption, thickness swelling, emission spectrum, bending strength, bending modulus, tensile strength and impact strength of rare earth fluorescent bamboo plastic composites were investigated by using contact angle meter, fluorescence spectrophotometer, electronic universal testing machine, pendulum impact tester and so on. The tensile fracture microstructure of rare earth fluorescent bamboo plastic composites was observed by field emission scanning electron microscopy. The results from water contact angle test showed that the water contact angles of composites unmodified and modified by hydrogen-containing silicone oil were 83° and 100°, respectively, which indicated that the unmodified composite was hydrophilic and the modified composite was hydrophobic. Analysis showed that the water absorption and thickness swelling of composites increased with the increasing of soak time and then leveled off. The water absorption and thickness swelling of modified composites were smaller than those of unmodified composites. Emission spectra showed that the relative luminous intensity peak of modified composites was 67.84% higher than that of unmodified composites before being soaked in water. The relative luminous intensity of them decreased with the increasing of soak time. After being soaked in water for 11 d, the relative luminous intensity of unmodified and modified composites was decreased by 46.40% and 28.82%, respectively, indicating that the modified composites possessed better luminous stability in water. Mechanical properties showed that the mechanical properties of modified composites were superior to unmodified composites before being soaked in water. With the increasing of immersion time, the flexural strength, flexural modulus and tensile strength of composites decreased and then leveled off, and the impact strength of composites increased at first, then decreased and finally leveled off. Compared with the unmodified composites, the modified composites had better mechanical properties after being soaked in water. For modified composites, the decreasing rates of bending strength, flexural modulus and tensile strength were smaller, while the decreasing rate of the impact strength was larger. However, the impact strength of modified composites was still bigger than that of unmodified composites after being soaked in water for 11 d. Field emission scanning electron microscopy showed that in the modified composites, strontium aluminate phosphors and bamboo powder dispersed very well, the agglomeration decreased, and the interfacial adhesion strength improved. Fourier transform infrared spectroscopy results showed that after the composites were modified by hydrogen-containing silicone oil, the number of free hydroxyl groups was decreased and hydroxyl absorption peak shifted to lower wavenumber. After modification, there was a new characteristic absorption peak attributed to the Si-CH3 groups appeared in 1387.75 cm-1, which indicated that chemical reactions happened between the hydrogen-containing silicone oil and the hydroxyl of bamboo fiber and strontium aluminate phosphor surface. The research results in this paper have great practical significance on improving water resistance of rare earth fluorescent bamboo plastic composites.
国家科技期刊平台
NSTL
万方数据
维普
