The Characteristicsin Fiber Cell Wallduring Stem Lignification Of Bambusa Pervariabilis

Bamboo is a kind of natural growth organisms, the mainly composed is cellulose, hemicellulose, lignin. Therefore, development of bamboo products, and gives high additional value is an important approach to alleviate the shortage of wood resources to establish research system of microcosmic mechanics for bamboo industrial utilization and bamboo building composite materials has important significance.Based on bambusa pervariabilisas the research object in this paper, adopts the X-ray diffractometer, single fiber tensile technology, nano-indentation methods systematic studied the microscopic characteristics and micro-mechanical properties of bambusa pervariabilis. Revealed the bamboo anatomical features and micro-mechanical properties variation rule affected by the age and positionof bamboo. Comprehensive increase the use value and provide certain theoretical basis for bambusa pervariabilis through micro-mechanical behavior and the nature of scientific. The results of the study are as follows:(1) Based on the research of bambusa pervariabilis anatomical features, and reveals thebambusa pervariabilis fiber cells and parenchyma cells, vascular bundle, tissueproportion(Fiber tissue, Parenchyma tissue, Conducting tissue) and the variation rule of microfibril angle. Fiber length, width and length-widthratiothe average value is 1.86pm,14.41μm,129.97, respectively. Fiber double wall thick, Parenchyma, microfibril angle is influenced by age of bamboo significantly; Radial, the size of fiber length, width, length-widthratio, double wall thickness, cavity diameter order is:the central> external> internal, vascular density increased gradually from inner to outer, microfibril angle variation regularity is not obvious; Longitudinal, fiber length and length-widthratio continuously rises from the base to upper, Fiber tissue proportion and conducting tissue proportion are increase, on the contrary, parenchyma tissue proportion is decrease, microfibril angle variation regularity is not obvious.(2) Based on the research of bambusa pervariabilis lignin distribution,and find out the lignin distribution characteristic of bambusa pervariabilis, thelignin main focus on the cell corner area (CCML) and middlelamella (CML) in the fiber cells, relatively few in secondary wall (SW), through quantitative analysis the content of lignin, the order of lignin content is:cell corner area(CCML)>cell middlelamella (CML)> secondary wall (SW). The lignin content increases with the age in cell corner area and cell middlelamella. Secondary wall lignin content is slightly different,the order is 2 years> 3 years> 1 year> that year was born, lignin content.overall decline along the fiber cap from vessels of protoxylem to the primary phloem sieve tube.(3) Based on the research of the bambusa pervariabilis single fiber mechanical properties, proved the variation of bamboo fiber mechanical properties along with the age, location. The average of bamboo fibre elastic modulus, tensile strength, elongation at break are 22.41 GPa,0.97 GPa and 4.52% respectively. Bamboo fiber mechanical properties variation regularity is not obvious with the age increase, variance analysis also shows that fiber mechanical properties affected by the age of bamboo was no significant; The radial, bamboo fiber elastic modulus increased from outside to inside, oppositely,elongation at break decreased, analysis of variance shows that the the relationship between radial position and the fiber tensile strength was significantly; On the longitudinal, bamboo fiber elastic modulus, tensile strength, elongation at break, elongation at break of the range of 21.58 to 23.61 GPa,0.92 to 1.03 GPa,4.16 to 5.01% along with the change of height respectively, According to the analysis of variance shows that the longitudinal position effect on bamboo fiber tensile properties was not significant.(4) Based on the research of the bambusa pervariabilis fiber cell wall mechanical properties, has proven the variation rule ofbamboo fiber cell walls mechanical properties. The hardness and elastic modulus of bambusa pervariabilis fiber cell walls were 17.97 GPa,475.69 GPa.2 years of cell wall elastic modulus, hardness were largest, bamboo ages had a great effect on the cell wall mechanical properties; Along the radial position different, middle position of the cell wall elastic modulus, hardness is minimum, and the largest of outside, meanwhile, The variance results also show that radial position for the cell wall elastic modulus, hardness impact were significantly; On the longitudinal, the fiber cell wall elastic modulus, hardness present growth trend with the increase of height, but the difference is not obvious, coefficient of variation were 25.48%,16.7%, respectively.(5) Through to analysis the bambusa pervariabilisanatomical properties and mechanical properties in the process of lignin. TheBambusa pervariabilis fiber length, width and length width ratio is not mainfactors to affectthe tensile strength of bamboo fiber,The fiber wall thickness, the cavity diameter and the cavity diameter ratio influence the tensile strength of the bamboo fiber.The relationship close between microfibril angle and tensile strength and tensile modulus.Lignin had significant influence on the tensilemodulus and hardness of cell wall, and it showed a positive correlation.The tensile modulus of single fiber tensile is greater than the cell wall tensile modulus.