Preparation And Characterization Of PBS/Bamboo Fiber And PBS/Bamboo Powder Composites

Waste plastics attract more and more attention from people since the serious "white pollution" problem with the Plastics industry flourishing development, Research and Development of biodegradable materials is regarded as the ideal approach to solve this problem. Poly(butylene succinate)(PBS) is one of the research focus in biodegradable polymers, which possesses excellent biodegradability and processability. Our country are rich in bamboo fiber (BF) and bamboo powder(BP) which are biodegradable and renewable materials. In this paper, PBS/bamboo fiber and PBS/bamboo powder composites were prepared by means of melt extrusion and injection moulding process. In order to prepare good performance biodegradable material as well as reduce production cost, full develop and use bamboo fiber and bamboo powder resources. The main content of this thesis includes:(1) The properties of short bamboo fiber reinforced PBS were investigated, Effect of bamboo fiber modified by silane coupling agent KH-560was better than titanate coupling agent and other silane coupling agents, an optimum dosage was obtained at KH-560content of5wt%. The best modification methods of bamboo fiber was mixed use of NaOH solution and KH-560, and the higher concentration of NaOH solution, the better properties; while the use of NaOH solution runs counter to the purpose of environmental protection, so it’s not suitable for industrial application. Flexural strength, impact strength and thermal distortion temperature of composites were improved by filled short bamboo fiber, however, the tensile strength reduced.(2) Our investigations show that the mechanical properties were significantly improved by addition of KH-560, the enhancement effect of long bamboo fiber was better than short bamboo fiber. The composites exhibit excellent performance when bamboo fiber treated by5wt%KH-560with the fiber content of35wt%, the tensile strength,flexural strength,impact strength and heat distortion temperature respectively increase by15.9%,122%,100%,36.8%compared to the neat PBS. Effect of injection pressure on the properties of composites was also investigated, the optimum injection pressure was found to at50MPa. The melting and crystallization of PBS and PBS/bamboo fiber composites was studied by DSC. The result show that the melting enthalpy, melting point and crystallization temperature of composites decreased compared with pure PBS resin, and a low crystallization temperature was observed in the.PBS/BF composites without coupling agent.(3) The thermal degradation behavior and tensile fracture morphology were observed by Thermogravimetric (TG) and Scanning electron microscope (SEM). PBS/BF composites showed an intermediate thermal stability between those of PBS and BF, the addition of KH-560also improved the thermal stability of the composite, which showed higher thermal degradation temperature than those without coupling agent. SEM showed that the fracture morphology of composites without KH-560was obvious brittle fracture behavior, significant fiber pull-out was observed; while there was no gap and hole were found in the composite which was surface modified by KH-560, those indicated that the interfacial bonding strength was improved by surface modification with KH-560.(4) The properties of PBS/bamboo powder were improved when bamboo powder surface modification by KH-560, and the optimum dosage was achieved at5wt%; Flexural strength and heat distortion temperature gradually increased with the increase of bamboo podwer. While impact strength and melt flow rate decreased with the increase of bamboo podwer content. The melting point and melting enthalpy of PBS/bamboo powder composites decreased compared with pure PBS resin, while the crystallization temperature increased, the result show that bamboo powder had the role of heterogeneous nucleation for composites.(5) Biodegradability of PBS/BF and PBS/BP was investigated by soil buried methods, tensile strength of composites gradually decreased and weight loss rate of composites gradually increased with the increase of degradation time. After a period of degradation, the surface of composites become coarse, but it was smooth for neat PBS, indicating that BF and BP improved the degradation of both polymers.