A polypyrrole-modified Fe3O4/SiO2/TiO2 composite material was successfully synthesized on the FST surface by in situ polymerization of pyrrole. Structural, morphological and magnetic response of Fe3O4/SiO2/TiO2/PPy(FST/PPy) were characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction pattern, Fourier transform infrared spectroscopy and energy-dispersive X-ray spectroscopy, etc. Through SEM images, the crystal sizes of the prepared FST/PPy nanoparticles were determined to be about 110 nm. The catalytic activity of FST/PPy was evaluated by the degree of decomposition of rhodamine B under ultraviolet and visible light, respectively. FST/PPy had the photocatalytic activity under the action of the light: the degradation rate of rhodamine B reached 92.8% and 63.5% after 3 h of UV and Vis light irradiation, respectively. Especially, compared with FST, the degradation rate has shown obvious improvement under the action of Vis light. Furthermore, FST/PPy photocatalyst could be easily recycled using a magnet.

Recycling the polymer material from the waste has a great advantage in reducing the cost of the biodegradable hot melt adhesive and solving environmental problems. Cellulose diacetate obtained from the acid hydrolysis of discarded cellulose triacetate‐based cinematographic films was blended with low molecular weight partially saponified polyvinyl acetate. The degree of substitution of cellulose diacetate and the degree of saponification of partially saponified polyvinyl acetate to obtain the binary blends having excellent compatibility were determined by FTIR and DSC. TGA showed that these blends have sufficient thermal stability for hot melt adhesive applications. The viscoelastic properties of the blends were evaluated by DMA and melt viscosity. The shear strength and the biodegradability of the final hot melt adhesive were examined according to the amount of cellulose diacetate in the blends. The results indicate that adding 20% of cellulose diacetate can reduce the cost of partially saponified polyvinyl acetate ‐based hot melt adhesive while improving the adhesive strength.

Cigarette butts are one of the toxic residues and have a very serious impact on the environment. Recycling cigarette butts has a great advantage in saving the natural source and solving environmental problems. Cellulose diacetate obtained from extraction, purification and acid hydrolysis of cigarette butts and then was blended with low molecular weight partially hydrolyzed polyvinyl alcohol. The blend of cellulose diacetate and partially hydrolyzed polyvinyl alcohol was characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. To evaluate the viscoelastic properties of the blends dynamic mechanical analysis was performed. The lap shear strength and the 180° peel strength of the adhesive were estimated according to the content of the blends and the biodegradability in water was confirmed. The experimental results showed that the use of cellulose diacetate obtained from cigarette butts in the composition of biodegradable hot melt adhesives can be of great help in solving environmental problems caused by petroleum-based polymers and waste.

Partially saponified low molecular weight (LMW) PVAc was synthesized and blended with a tackifier for use as hot-melt adhesive with water-solubility and biodegradibility. The water-solubility of the partially saponified LMW PVAc was determined as a function of the degree of saponification. PVAc prepared in this study had good water-solubility because its molecular weight was very small and it had lots of hydroxy groups in the polymer chain. As the degree of saponification increased, the solubility of PVAc in water increased. The glass transition temperature and viscoelastic properties of partially saponified PVAc were measured and analyzed by using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). As the temperature increased and the degree of saponification decreased, melt viscosity decreased. The single lap-shear strength and biodegradability of the hot-melt adhesive on based PVAc were systematically evaluated. As the degree of saponification of the polymer increased, the single lap-shear strength of the hot-melt adhesive and the tendency for cohesive failure to occur decreased. The higher the degree of saponification, the faster the rate of biodegradation of the adhesive in natural water.