A new type of natural fiber reinforced composite was prepared and characterized. The reinforcement was bamboo fiber and the polymer matrix was polypropylene (PP). The bamboo tube was first machined into culms, then milled, and finally separated by Endecotts test sieves. In order to enhance the bonding between the bamboo fiber and the matrix, maleated polypropylene (MAPP) was prepared by a grafting reaction between maleic anhydride and PP in solution. The composites were prepared with the dried bamboo fiber, the control PP, and MAPP. The composition of MAPP varied from 10-50 wt.% while the total ratio of bamboo and polymer, both control PP and MAPP, was kept to about 50:50. It was found that the tensile strength of MAPP enhanced composites was about 26-36 MPa, whereas the tensile strengt...[ Read more ]

A new type of natural fiber reinforced composite was prepared and characterized. The reinforcement was bamboo fiber and the polymer matrix was polypropylene (PP). The bamboo tube was first machined into culms, then milled, and finally separated by Endecotts test sieves. In order to enhance the bonding between the bamboo fiber and the matrix, maleated polypropylene (MAPP) was prepared by a grafting reaction between maleic anhydride and PP in solution. The composites were prepared with the dried bamboo fiber, the control PP, and MAPP. The composition of MAPP varied from 10-50 wt.% while the total ratio of bamboo and polymer, both control PP and MAPP, was kept to about 50:50. It was found that the tensile strength of MAPP enhanced composites was about 26-36 MPa, whereas the tensile strength of the composites without MAPP was found around 15 MPa. Other effects on the mechanical properties were also discussed in this thesis, such effects are bamboo fraction, the size of bamboo fiber, the content of maleic anhydride, and the mixing condition.

It is always the most important factor to a successful design of any engineering composite materials that adhesion between the reinforcement and the polymer matrix should be enhanced. In this study, the maleated PP was adopted as the compatibilizer. In order to understand better the enhancement mechanism, the morphology of the bamboo fiber reinforced composite was also studied. The crystallization behavior of the control PP and MAPP on the bamboo fiber was studied by means of polarized optical microscope. The bamboo induced MAPP transcrystalline was found on the bamboo fiber surface, whereas such effect for pure PP is not significant. The interfacial morphology of the bamboo fiber reinforced polypropylene (BFRP) composites was studied by using scanning electron microscope, x-ray diffractometer, and optical microscrope. Furthermore, the crystallization kinetics was studied by DSC. β-crystalline phase was found in all the BFRP composites, however, such crystalline phase was not found in the pure PP and maleated PP. The crystallization temperature increased with the addition of bamboo fiber.

The composites were prepared by means of hot press. The BFRP composites were compared to the commercial wood pulp board produced by compounding, and it is found that the tensile strength of the new composites is four times higher than that of the commercial product, while other mechanical properties, such as the modulus, the yield strength, the impact strength are all comparable to those of commercial product.