| The research objects of this paper are fibers of 12 bamboo species, including M, Ma, L, C, CG, DS, FD, H, HM, QS, S, and YS, respectively representing Phyllostachys heterocycla cv. var. pubescens(Mazel) ohvoi, Dendrocalamus latiflorus Munro, Dendrocalamopsis oldhami(Munro) keng f., Neosinocalamus affins (Rendle) keng f., Bambusa pervariabilis McClure Dendrocalamopsis vario-striata(W.L.Lin) keng f., Bambusa chungii McClure, Bambusa albo-lineata (McClure) Chia, Bambusa longispiculata Gamble ex Brandis, Bambusa eutuldoides McClure var. viridi-vittata (W.T.Lin) Chia, Phyllostachys heterocyclada Oliver and Bambusa multiplex (Lour.) Raeuschel ex J. A. et J. H. Schult. var. multiplex cv. Silverstripe R.A.Young, which are main bamboo species in Fujian province. The development and utilization of bamboo fibers must be based on their properties. Analyzing on variance laws of bamboo fiber properties, such as fiber morphology, pit features in cell wall, chemical components, chemical group characteristics, DP of cellulose and mechanical properties with different impact factors in the hope that it could provide theoretic direction of optimizing selection on raw bamboo fibers and designing of high-performance bamboo products. Cluster analyzing on the above bamboo species according to these fiber properties in the hope that it could provide a new classify approach of bamboo species.1. The fibers of 12 bamboo species in Fujian province are long and thin but stiff, and their cell cavity are thin while the cell wall are thick. Both in tangential cell wall and in radial cell wall all rarely but uniformly distribute a small amount of single pits or boarded pits, the diameter of which are shorter than 1μm and these pit features are remarkably different from those of most wood fibers.2. In terms of fiber length lever, the fibers of 12 bamboo species in Fujian province are basically defined as medium or long fiber and they mostly distributed between 1000μm and 2500μm, which accounts for the rate of 70.16%~86.12%. On average, the fiber length, fiber width, ratio of fiber length to width, fiber wall thickness, fiber cavity diameter and ratio of fiber wall thickness to cavity diameter of these bamboo species are 1255.18~2330.88μm, 11.61~17.64μm, 96.27~196.96, 2.59~6.11μm, 1.17~3.49μm, 1.83~8.62 respectively. Both bamboo ages and positions of bamboo culm have significant or extremely significant influence on most indexes of fiber morphology for different bamboo species, but the variation laws are specify for different bamboo species and different indexes of fiber morphology. Generally, among different vertical positions in bamboo culm, fiber length and ratio of fiber length to width in 2.5m and 4.5m above ground were the maximum.Fiber wall thickness in 0.5m and 2.5m above ground were the maximum while in 4.5m was the minimum. Fiber cavity diameter in 2.5m above ground was the maximum while in 0.5m was the minimum. Ratio of fiber wall thickness to cavity diameter in 0.5m above ground was the maximum while in 4.5m was the minimum. When bamboo ages increases, on average, the fiber length in 0.5m, 2.5m and 4.5m of vertical positions in bamboo culm for M, Ma and L all increase or increase to four-year-old then decrease while ratio of fiber wall thickness to cavity diameter of those perform similarly to the latter, additionally, fiber wall thickness and fiber cavity diameter of these three bamboo fibers basically increase while ratio of fiber length to width of those perform irregularly.3. The content of nitric acid-ethanol cellulose and pentose of bamboo fiber vary with different dissociating methods and the dissociating method"30%H2O2: 95%HAC: H2O= 4:5:21"is relatively milder. The content of fiber nitric acid-ethanol cellulose for eight kinds of four-year-old bamboo species, including C, CG, DS, FD, M, L, Ma, and S, are between 80.49% and 87.89%, which are less than that of cotton fiber but higher than flax fiber and benne fiber while the fiber pentose content of those are between 13.33% and 87.89%, which are higher than that of cotton fiber, benne fiber and flax fiber. The fiber nitric acid-ethanol cellulose content of M, Ma and L increase with bamboo ages from one-year-old to four-year-old then decrease while fiber pentose content of those decrease all the time.4. DP of fiber cellulose for eight kinds of four-year-old bamboo species, including C, CG, DS, FD, M, L, Ma and S, are between 958 and 1141 , and the viscosity-average molecular weight of those are between 1.5×105 and 1.8×105.DP of fiber cellulose decreases when time prolongs.5. FTIR characteristic absorption peaks and their afflictions of different bamboo species in the same age perform similarly. Eight kinds of four-year-old bamboo fibers, including C, CG, DS, FD, M, L, Ma, and S, possess absorption peaks in 3421~3431cm-1, 2919~2924cm-1, 1733~1735cm-1, 1632~1634cm-1, 1375~1378cm-1, 1162~1165cm-1, 895~896 cm-1, which suggests that the main chemical components of bamboo fiber are cellulose, hemi-cellulose and lignin. However, other absorption peaks representing the three main chemical components are small or even don't appear at all, which suggests that the basic structure of lignin has been disintegrated to some degrees and it also inevitably degrades cellulose and hemi-cellulose while removing a great amount of lignin in disssciating bamboo fibers.6. Tensile strength of four-year-old M and Ma, on average, is 1.81 GPa and 2.58GPa respectively, while tensile modulus of the two bamboo species is 28.87 GPa and 46.61 GPa respectively. Judging by tensile strength and tensile modulus, the fiber of Ma is superior to that of M but they all obviously better than wood fiber.7. On the basis of seven properties, the paper cluster classifies eight bamboo species, including C, CG, DS, FD, M, L, Ma, and S, which indicates that M and Ma have the high similarity and are of the same class earlier, so are C and FD. Supposing they would be classified as two types, C, CG and FD would be classified as one type and the other six bamboo species as another type.
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