Fabrication And Properties Of Biodegradable PBS Composite Reinforced By Jute Fiber

People constantly emphasize the environmental awareness and also make new demands for the degradation of fiber reinforced composites with the development of society. Therefore, the fully biodegradable composite, using environment-friendly and cheap natural fiber as the reinforcement and completely biodegradable polymer as the matrix, has not only an excellent cost-effective and also of great significance for the current environmental protection and sustainable development issues. Jute fibers which are low cost, high specific strength and modulus have potential industrial applications as reinforcement materials of the composite. Poly(butylene succinate) (PBS) entering the field of materials research in the 1990s rapidly become a research hotspot as a widely used general and completely biodegradable plastic.A jute/PBS biocomposites based on short jute fiber as the reinforcement and completely biodegradable PBS as the matrix were fabricated by the method of molding in this paper, and the effect of fiber retting degree, content and surface modification on the properties of the biocomposites, as well as their biodegradability were also studied.The original jute fibers (the residual glue rate is 14.37%) were alkali scoured to obtain jute fibers of different residual glue rate of 4.73% and 2.60%. In order to study the effect of fiber retting degree on the properties of jute/PBS composite, the biocomposites reinforced by the above three types of jute fibers were prepared and experimented to compare their properties. The results show that compared with pure PBS, the jute/PBS composites have improved strength and modulus. And the improved degree is more obviously for the composite reinforced by jute fibers of residual glue rate of 4.73% and 2.60% than that by original jute fibers. However, it has no obvious difference between the composite reinforced by jute fibers of residual glue rate of 4.73% and 2.60%. The elongation at break and toughness of jute/PBS composites decreases than pure PBS, with slightly difference among the composites reinforced by different jute fibers.The effects of fiber content, 10%, 20% and 30%, on the properties of composites were researched. The experimental results show that a certain content of jute fiber can significantly improve the mechanical properties of composites. With the increase of jute fiber content, the tensile strength of composites firstly increases and then decreases, reaching the maximum at the fiber content of 10%, which increase by 30.1% than that of pure PBS; the flexural strength and modulus gradually improve, the flexural modulus increase by two times than that of pure PBS at the fiber content of 30%; and the elongation at break gradually decreases.Effects of surface modification by alkali and silane coupling agent KH-570 on the properties of composites were studied by mechanical properties tests, FTIR and SEM, respectively. Experimental results show that, the surface modification by alkali and silane coupling agent KH-570 can both increase the surface rough of jute fibers, so as to improve the cohesive strength between jute fiber and PBS, and furthermore to improve the mechanical properties of jute/PBS composites, especially their flexural modulus, which are enhanced by 59.4% and 90.2% respectively. And the studies also show that the effects of silane coupling agent KH-570 are more obvious than those of alkali.The biodegradability of the jute/PBS composites was evaluated by the soil-burial test, and their surface morphology after degradation was observed. According to the results, it could be observed that the jute/PBS composites have more significant degradation rate than pure PBS, which reach the maximal weight-loss of 8.69% after 30 days at the fiber content of 10%. And among the fiber content of 10% and 30%, the composites have gradually decreasing weight-loss with the increase of fiber content. Experimental results also show that surface treatments have slightly effects on the weight-loss of composites. Surface-morphology observation shows that, the surface of degraded materials become uneven and emerge holes because of the dissolution of degradation products.