Study On Chemical Composition And Properties Of Banana Fibers

With the development of economy and technology of textile,“green, environmentalprotection, nature”has become the target of textile industry. Because of the fact that naturalplant fibers are renewable, biodegradable and low price, people have begun to pay moreattention to it. Banana fiber is made of banana stalk, and it has the advantages of light weight,small elongation, high strength, fast moisture absorption and release, etc. At the same time,our country has abundant banana stems as raw materials. The development and utilization ofbanana fiber can not only solve the problem of waste straw pollution to environment, but alsobring economic benefits. Banana fiber has a great prospect for development.Through the quantitative analysis of chemical composition of banana fiber, we canunderstand the chemical composition of banana fiber. The composition: cellulose content of44.75%, hemicellulose content of27.53%, lignin content of15.65%, pectin content of2.59%,fat and wax content of1.93%, ash content of3.72%.By comparison with the hemp fiber, thisthesis holds the position that the gum content of banana fiber is higher than hemp fiber. Thelignin content is very high, and in the degumming process we should take into account theelement to the removal of lignin.This thesis adopts the evaluation indexes of residual gum content, whiteness andbreaking strength. Based on single factor experiment and orthogonal experiment, this thesisconcludes that the optimum process of banana fiber degumming is: density of sodiumhydroxide3.5g/L, density of hydrogen peroxide6.5g/L, reaction temperature100℃,reaction time105min, amount of sodium silicate3%, dosage of sodium sulfite2%, urea2%,dosage of JFC3%. Through the effect comparison of sodium carbonate degumming withsodium hydroxide degumming, this thesis reaches the conclusion that sodium hydroxide isbetter than sodium carbonate as alkali in degumming process. By investigating thedegumming effect in different proportion of sodium hydroxide and sodium carbonate, thisthesis concludes the optimum mixture ratio: sodium hydroxide: sodium carbonate is3:7. Bycomparing the effect of mixed alkali degumming with sodium hydroxide degumming, weconsider that using sodium hydroxide in degumming is better. Finally, through thecharacterization of IR and XRD between degumming and not degumming fibers, this thesisproves that the cellulose content of banana fiber increases after degumming.Using SEM to test the appearance of the banana fiber, this thesis finds many impuritieson the surface of banana fiber, single fiber conglutination and rough surface. By IR test of banana fiber, this thesis summarizes that it is the cellulose fiber that has good moistureabsorption, and the main groups of banana fiber is concluded. By means of XRD method, thisthesis calculates that the crystallization of banana fiber is72.65%and the degree oforientation is0.984.The average density of banana fiber measures77.4dtex by middleweighing method. Through the analysis of the mechanical properties of banana fiber, theaverage fracture strength of banana fiber is19.09cN/dT and the average initial modulus is54.43cN/dT. The average moisture content of banana fiber is7.45%.