Mulberry Fiber And Chemical Extraction Methods And Performance

The chemical ingredient of mulberry is tested according to GB5889-86 'Method of quantitative analysis of ramie chemical components' in this paper. The results indicated that the cellulose of mulberry bast is lower than others. It is 28.6%. But the pectin and water-soluble of mulberry bast is higher than the hemp. The hemi-cellulose is approximately 15.7% and the lignin is 9.6%.The chemical degumming process of mulberry bast is preparation - pretreatment -washing - soda boiling (the first boiling- washing- the second boiling) - washing -to hit the filament - neutral -washing - dewatering - to give oil - dewatering - drying. The treatment parameter of the first boiling is determined by the degumming method of hemp and the former experiments of mulberry. The result showed that alkali is 10g/L, time is 1 hours, temperature is 75℃, the liquor ratio is 1:10, open kier boiling. The optimum conditions of mulberry bast preparation and the secong degumming are determined by orthogonal test. The test result showed that hydrogen peroxide concentration was5g/L, Urea was concentration 8%owf, temperature was 75℃, Time was :90 min. The second boiling :alkali is 10g/L, sodium polyphosphate is 8%owf, sodium silicate is 8%owf, time is 3 hours, the liquor ratio is 1:10, temperature is 100℃. Degumming mechanism has been analysis.The two-step boiled samples were tested including length, fineness, breaking tenacity, breaking extension rate, moisture regain, Mass Specific Resistance, friction coefficirnt, morphological structure, X-ray, Differential Scanning Calorimetry(DSC) , Structural disruption was observed by X-ray measurement. The results indicated that the length of mulberry fiber is 23 mm, fineness is 3.2 dT, breaking tenacity is 73 cN/tex, breaking extension rate is 5%, moisture regain is 9%, Mass Specific Resistance is 10~7Ω·g/cm~2. The mulberry fiber belongs to the cellulose I by X-ray measurement. The treated mulberry fiber compared with untreated fiber represented an increase of crystallinity and the micrite size. Its characteristic spectrum line is consistent. The structure of cellulose has not been changed. The DSC results indicated the glass-transition temperature of mulberry fiber is not obvious. The mulberry fiber began endergicity, carbonization and decomposition when temperature is 316.00℃. There is without molten heat absorption peak.