Preparation And Characterization Of Starch / PVA Composites Reinforced With Modified Bagasse Fiber

Bagasse fiber provides many characteristics, such as abundance, low cost and high specific strength. The utilization of modified bagasse fiber as reinforcement in starch/PVA degradable matrices can reduce the environmental pollution, but also can reduce the high cost of biodegradable materials and improve the utilization of bagasse fiber. It has great economic and social value.After Na OH treated bagasse fiber, infrared spectroscopy(IR) indicated the hemicellulose was removed and the lignin content was reduced. Compared with the untreated bagasse, thermogravimetry(TG) showed that the thermal stability of bagasse fiber with Na OH treatment showed improvement. X-ray diffractometery(XRD) indicated that the crystallinity of modified bagasse decreased. The occurrence of swelling, loose and porosity for surface modification on the bagasse fiber was observed by SEM. Mechanical properties of the composites made from Na OH treated bagasse fibre were superior to the untreated fiber.When the Na OH concentration was 3 %, the treatment time was 4 h and the modified bagasse content was 50 phr, the mechanical properties of bagasse fiber/starch/PVA composite showed best, the tensile strength and tensile modulus of composite were 8.98 MPa and 635 MPa, respectively. Approximately 71.05 % improvement in tensile strength,67.11 % in tensile modulus had been found, respectively.After KH550 treated bagasse fiber, the absorption peak at 1252 cm-1 assigned to the vibration of Si-O-cellulose, the absorption peak at 1122 cm-1 and 1037 cm-1 assigned to the vibration of Si-O-Si bond, indicating that KH550 was efficiently held on the fiber surface.TG showed that the thermal stability of bagasse fiber with KH550 treatment had improved.The occurrence of porosity for surface modification on the bagasse fiber was observed by SEM. Mechanical properties of the composites made from KH550 treated bagasse fibre were superior to the untreated fibre. When the KH550 concentration was 1% and the modified bagasse content was 50 phr, the mechanical properties of composite showed maximum improvement, the tensile strength and tensile modulus of composite were 9.89 MPa and 685 MPa, respectively. Approximately 88.39 % improvement in tensile strength, 80.27 % in tensile modulus had been found, respectively.After treatment with Na OH/KH550, IR indicated that the hemicellulose was removed,the absorption peak at 1126 cm-1 assigned to the vibration of Si-O-Si bond, indicating that KH550 was efficiently held on the fiber surface. TG showed that the thermal stability of modified bagasse fiber was more thermally stable than untreated bagasse fiber. Theoccurrence of porosity and loose for surface modification on the bagasse fiber was observed by SEM. Mechanical properties of the composites made from KH550/KH550 treated bagasse fibres were superior to the untreated fibre. When the KH550 concentration was1.5 % and the modified bagasse content was 50 phr, the mechanical properties of composite showed maximum improvement, the tensile strength and tensile modulus of composite were13.15 MPa and 957 MPa, respectively. Approximately 150 % improvement in tensile strength,152 % in tensile modulus had been found, respectively.The solid-phase grafting of maleic anhydride(MAH) onto sugarcane bagasse, The IR analysis showed that the carbonyl absorption peak at 1719 cm-1appeared, which can be a qualitative description of maleic anhydride was grafted onto bagasse fiber. TG analysis showed that the thermal stability of modified bagasse fiber was similar to the untreated fiber.XRD results showed that the crystallinity on the fracture surface of NSB-g-MAH showed a number of holes, fold curl and specific surface area increased.The results showed that graft copolymer with higher grafting ratio and grafting efficiency was obtained when MA mass is5 % of sugarcane bagasse, BPO mass is 6 %, the reaction temperature is 80 ℃, and the reaction time is about 2 h.