| The bamboo resources is very rich but with low processing and comprehensive utilization in China,so the high using of bamboo resources(quantity,quality,economic)have been the key technology to improve the economic efficiency in the area of domestic bamboo.P.Pubescens which have the characteristics of large area,wide distribution,high economic value and huge production potential belongs to gramineae bambusoideae phyllostachys,monopodial,and also had the feature of high strength,good rigidity and wear resistance,however,the P.Pubescens researched by domestic scholars mainly concentrated in the stem part at present.With the development to the depth and the increasing demand for bamboo resources,the research field has gradually developed into the direction of efficient utilization in recent years.Bamboo in the upgrading process produced more leftovers,such as rhizome,which was the underground system,bamboo not only depended on the underground system to absorb water and nutrients from the soil for bamboo leaf photosynthesis to make organic material,but also relied on the rhizome bud to pregnancy bamboo into reproduction.As an important component of P.Pubescens,the rhizome with the quality of high strength and high tenacity come into the sight of people in the environmental protection today,because the resource which come from the renewal transformation processing of low yield forest was very rich,but low utilization,the rhizome was used to make the rod and root carving handicraft in folk custom,etc.In this paper,there was a comprehensive and systematic study on the chemical properties at different ages,and discussed the corresponding characteristics of changing rule not only to provide a theoretical reference to the bamboo forest management,but also have important significance in expanding the scope of bamboo utilization and enhancing the added value of the bamboo.Three parts including anatomical properties,chemical properties,thermal properties of rhizome were studied in this paper,and using modern instruments such as XRD,TG,DSC,analyzing the fiber morphological,chemical composition variation characteristics,the thermal properties parameters.The main results were as follows:(1)The fiber average length,fiber diameter,lumen diameter,double-wall thickness,double wall thickness lumen ratio,lumen diameter-diameter ratio and length-width ratio of coming rhizome were 698.555?m,21.710?m,11.375?m,10.335?m,0.967,0.52,0.522 and 34.723 respectively,and the going rhizome were 921.314 ?m,23.258 ?m,14.090 ?m,9.544 ?m,,0.747,0.585,40.129 respectively;(2)There was no significant difference both between fiber diameter and lumen diameter of the coming rhizome at different ages.However,for its fiber length and length-width ratio,the difference between different ages was extremely significant(1-year to 3-year,3-year to 5-year)and no significant(1-year to 5-year).While,the difference of double-wall thickness,double wall thickness lumen ratio and lumen diameter-fiber diameter ratio between different ages was significant(1-yearto 3-year),extremely significant(1-year to 5-year)and no significant(3-year to 5-year);(3)The difference of fiber length of going rhizome between different ages was extremely significant(1-year to 3-year,3-year to 5-year)and no significant(1-year to 5-year),there was no significant difference on both fiber diameter,double-wall thickness and double wall thickness lumen ratio.However,for its lumen diameter and length-width ratio,the difference between different ages was extremely significant(1-year to 5-year,3-year to 5-year)and no significant(1-year to 3-year).(4)The ash contents of the rhizome and culm of P.pubescens at different ages showed the largest coefficient of variation(CV),followed by alcohol benzene extractives.The CVs of acid-insoluble lignin,holocellulose,HNO3-C2H5 OH cellulose and pentosan were relatively small.(5)Analysis of T-tests indicated that significant differences were found in the contents of extractives(r< 0.04),ash and pentosan of rhizome and culm(r< 0.01).The differences in contents of acid-insoluble lignin,holocellulose,HNO3-C2H5 OH cellulose were not significant.(6)Multiplicity analysis found that there were no significant differences(p > 0.05)in the contents of HNO3-C2H5 OH cellulose,pentosan,and ash in bamboos between different ages.Also,other contents including lignin,alcohol benzene extractives,and holocellulose exhibited no significant difference between one-year-old and three-year-old bamboos.However,the differences in these parameters between five-year-old bamboos and one-year-old and three-year-old bamboos were all statistically significant.(7)Analysis of a variance found that the ash content of P.Pubescens between coming rhizome and going rhizome was significant differences,while the extractives,acid-insoluble lignin,holocellulose,HNO3-C2H5 OH cellulose and pentosan contents showed no significant difference.(8)Both the cellulose relative crystallinity of rhizome and culm of P.Pubescens were all increased and then appreciably decreased with the increase of ages,and the contents of rhizome is lower(about 10%)than that of culm.(9)The glass transition temperature(Tg)of rhizome was higher than that of culm in the temperature range 268.8 ?to 273.8 ?,while that of the culm was 213.9 ?to 219.4 ?,and there was no significant difference among rhizome or culm in the aspect of Tg at different ages.(10)The extrapolation initial decomposition temperature(Te)of 1-year,3-year and 5-year rhizome were respectively 263.7 ?,266.1 and 263.9 ?,meanwhile the Te of culm were respectively 289.7 ?,282.8 ?and 283.4 ?.The variance analysis showed that there was no significant differences in the aspect of Te among the same parts of its rhizome and culm at difference ages,but the Te of rhizome was lower than culm at the same age. |
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