| To make the full use of bamboo logging residues,actually realize the "zero" surplus of bamboo resources and high-value use of bamboo materials,this paper taked the moso bamboo logging residues as the research object,and studies on the basic properties of bamboo logging residues.,prepared good compatibility biodegradable films by pretreatment,etherification,cross-linking,blending,etc.The properties and degradation mechanism of the biodegradable films were tested and discussed through infrared spectroscopy(FT-IR),X-ray diffraction(XRD),thermogravimetric analyzer(TG),scanning electron microscope(SEM),which opens up new ways for the removal of the bamboo logging residues,which is important significance for improving the ecological environment and saving resources.The main results and conclusions of the paper are as follows:1)Moso bamboo residues,as well as bamboo stems,are composed of cellulose,hemicellulose,and lignin.Among them,the content of ?-cellulose is 43.12%,which is slightly lower than that of bamboo stems(43.44%);The total amount of non-cellulosic components such as lignin,hemicellulose,ash,and extractives of moso bamboo logging residues was higher than that of the moso bamboo stems;The fiber morphology of the residue of bamboo logging is similar to that of bamboo stems,and it is a kind of fiber with small wall thick cavity.2)Using bamboo residues as raw materials,preparation of carboxymethylcellulose sodium,an intermediate product of biodegradable films,with a series of chemical reactions such as cooking,delignification,bleaching,alkalization,and etherification.The degree was 0.886 and the viscosity was 78.9 m Pa.s,which was higher than the degree of substitution and viscosity of sodium carboxymethyl cellulose prepared by the moso bamboo stems(degree:0.733,viscosity:17.3 m Pa.s).3)Through the discussion of the effects of different thickeners,different cross-linking agents,and different plasticizers on the biodegradable film,the optimum formulation of the biodegradable films was as follows: the sodium carboxymethyl cellulose concentration is 2%,sodium carboxymethyl cellulose: sodium alginate:starch = 10:3:1(mass ratio),thickeners glutaraldehyde and boric acid are 3% by volume added to distilled water and added carboxymethyl cellulose At 3% of the sodium mass,the plasticizers glycerol and urea were 3% by volume of distilled water added and 2% by mass of sodium carboxymethylcellulose added,and the hydrophobicagent was 3% by volume of distilled water.4)The biodegradable films prepared by the moso bamboo logging residues showed good compatibility,smooth surface,compact structure,good water retention and moisture retention.The tensile strength was 7.437 MPa,the elongation at break was 54.792%,the tear strength is 14.894 k N/m,the light transmittance was 87.5%,and the performance was better than that of biodegradable film prepared from bamboo stems(strength: 4.814 MPa,elongation at break: 26.464%,the tear strength:10.432 k N/m).Degradation experiments found that biodegradable films prepared from the logging residues of moso bamboo had a lot of voids on the surface 80 days after the soil was buried.The edges of the biodegradable films appeared jagged and cracked into pieces.The mechanical properties were basically absent,whereas the biodegradable films degraded in the soil.The nutrient content increased,in which the content of N in the soil increased by 3%,the number of fungi increased by 154%,the organic matter increased by 5.4%,and there was little change before and after the degradation of the soil p H film.Using infrared spectroscopy to analyze the films before and after degradation,it was found that under the action of microorganisms and water molecules,the biodegradable films was cut off,the intermolecular forces were reduced,and the macromolecules were depolymerized into small molecules to achieve the purpose of degradation. |
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