| Wettable powder （WP） and water dispersible granules （WG） are kind of solidformulations of pesticides which could form a stable dispersion for spray use. WP and WGhave the advantages of nonsolvent pollution, security, convenient packaging andtransportation. And WP is cheap to use and WG is dustless. All of these make them widelyutilizied. WG is one of the most popolar pesticide formulations in21thcentury. Especially itssolvent-free advantage, WP and WG used as a substitute of emulsion formulations, highconcentrations of WG and WP must be pesticide research trends.Industrial lignin is mainly from papermaking waste, which is abundant sources,inexpensive, non-toxic. Due to its general application performance, it is difficult to meet therequirements of the high quality of WG and WP formulations of dispersant, so appropriatechemical modification should be made to improve its application performance. Industriallignin modification as the dispersing agent of pesticide can not only improve the use value ofthe paper waste and reduce environmental pollution, but promote the development andapplication of green pesticide additives and solvent-free pesticide formulations. However, dueto the diversity of pesticide, effects of modified lignin dispersant in the different pesticides aredifferent. Therefore it requires in-depth study of matching law between the modified methodand the molecular structure of the modified lignin and pesticide varieties, but the present lackof such basic research.In this thesis, influence of single oxidation, hydroxymethylation and sulfonation on theregular of structural properites of black liquid, and application performance of modification ofthe black liquid of40%myclobutanil WP,80%dimethomorph WG and40%isopropyl WPare researched systematically. Based on this research, an efficient pesticide dispersants wasdeveloped from industrial lignin as raw material through chemical modificatio, and comparedthe dispersion properties of the dispersant in the different pesticide formulations. Ultrafiltration of black liquid （UBL） of single oxidation reaction, singlehydroxymethylation reaction and single sulfonation can increase the content of carboxylicacid from1.92mL·g-1respectively to the largest3.19mL·g-1,2.86mL·g-1,3.76mL·g-1. Afteroxdidation and sulfonation, the content of phenolic hydroxyl group of UBL rised from1.09mL·g-1respectively to the largest1.80mL·g-1and2.10mL·g-1, water-soluble rate increasedfrom42.5%of UBL to a maximum of78.89%（reaction temperature90℃） and99.27%（reaction temperature75℃）. The products of sulfonation appeared sulfonic acid groups.Phenolic hydroxyl content of UBL and water-soluble rate of the hydroxymethylationmodified products no changed significantly. Oxidation and hydroxymethyl modificationrespectively can increase the intrinsic viscosity of black liquid to a maximum of9.85mL·g-1and21.02mL·g-1. But the sulfonated products reduce the intrinsic viscosity of UBL.Single sulfonated products are used better in the Myclobutanil WP （the suspension rate is82.53%）, Dimethomorph WG （95.29%） and Isoprocarb WP （91.73%）, because of highquantity of total hydrophilic group and a certain amount of sulfonic group. Single-hydroxymethyl products can be better used in more hydrophobic pesticides, the stronghydrophobic ability of its large molecular weight may have played a role. The performance ofoxidation products used in three pesticide formulations are worse than thosehydroxymethylation and sulfonation.Efficient lignin pesticides dispersant GCL4-UBL is developed by oxidation,condensation and sulfonation using industrial lignin as raw material. As a dispersantGCL4-UBL has a good performance in the WP and WG. Before the heat storage suspensionrate of Myclobutanil WP, Dimethomorph WG and Isoprocarb WP were86.21%,92.37%and87.70%, higher than the foreign commonly used dispersant BN （80.16%,68.45%and71.84%）.The analysis of IR, UV, intrinsic viscosity, elemental analysis, IC and so on indecatedthat it appeared sulfonic acid groups absorption peak at1194cm-1and1043cm-1in theGCL4-UBL which could prove that sulfonic acid group comed up in GCL4-UBL molecules.Intrinsic viscosity of GCL4-UBL is5.81mL·g-1, the contents of phenolic hydroxyl, carboxylic acid group and sulfonic acid group are1.49mmol·g-1,3.12mmol·g-1and0.32mmol·g-1.The effect of the Zeta potential and the contact angle of GCL4-UBL, BN, and UBLon different pesticides were studied. It is found that the GCL4-UBL has the best wettingproperties. The contact angles of GCL4-UBL on the Myclobutanil, Dimethomorph andIsoprocarb are37.5o,36.5oand44.5o. The maximum Zeta potentials of suspension of threepesticides are respectively30.6mV,71.73mV and48.96mV. |
PDF Full Text Request