| In this paper,we synthesized the organosilane-modified polycarboxylate dispersants（P（AA3-APEG1-Six））usingγ-（trimethoxysilyl）propyl methacrylate（MAPTMS）,allyl polythoxyether（APEG-1000）and acrylic acid（AA）as monomer,which included excellent wettability and dispersing properties.Herein,the reaction process were designed and explored mainly,and the influence on the performance of organosilane-modified polycarboxylate dispersants of different amount of MAPTMS were investigated.Moreover,the physicochemical properties of SC obtained by P（AA3-APEG1-Six）were investigated in detail.The main contents and results are as follows:（1）The organosilane-modified polycarboxylate dispersants were synthesized by radical copolymerization.Several key factors such as temperature,monomer ratio,initiator and chain transfer agent dosage,and the materials adding order were investigated and discussed.Meanwhile,the molecular weight,PDI and surface tension of different dispersants as the evaluation criteria,and the synthesis process of the target product was finally determined.The P（AA3-APEG1-Six）dispersants with different MAPTMS contents ranging from 0 to 0.5 mol were obtained by keeping the molar ratio of AA/APEG constant at 3:1,the initiator addition was 2 wt%and the chain transfer agent was 1.5 wt%,the polymerization reactions at the 70℃ for 2h after all materials were add separately.Finnally,FT-IR spectrum and 1H NMR spectra further prove that MAPTMS was present in P（AA3-APEG1-Six）.（2）By testing the properties of surface performance（such as CMC,γcmc,Γmax,Amin,ΔGmic,ΔGads,etc.）,emulsification properties,HLB values,and wettability of the organosilane-modified polycarboxylate dispersants at the gas-liquid interface,the effects of different amount MAPTMS on physicochemical properties of P（AA3-APEG1-Six）were discussed.The results show that the surface tension of P(AA3-APEG1-Si0.5)is the lowest,and when the amount of MAPTMS is 0.14～0.5,itsγcmc,cmc and Amin decrease,andΓmax increases with the amount of MAPTMS increases;Especially Theγcmc and cmc of P（AA3-APEG1-Si0）are lower than those of P(AA3-APEG1-Si0.14)and P(AA3-APEG1-Si0.25).Secondly,compared with P（AA3-APEG1-Si0）,the HLB value and emulsification time increased of the P（AA3-APEG1-Six）modified by MAPTMS,the emulsification time of P(AA3-APEG1-Si0.5)was the largest,and the emulsification stability was the best.Finally,the wettability research of P（AA3-APEG1-Six）found that the four dispersants all have excellent wettability,and the contact angle of P（AA3-APEG1-Six）on the paraffin film were consistent with the surface tension.（3）The properties of 25%tebuconazole suspension concentrations obtained by P（AA3-APEG1-Six）,including the particle size,zeta potential,suspension rate,and rheological behavior,were investigated in detail.Moreover,The surface tension of the dilute solution of the SCs and the contact angle on the plant（rice,basil and green vegetables）were used to evaluate their wettability.The results showed that the polycarboxylate dispersants modified by MAPTMS improved the dispersion stability of the SC significantly.With the increase of MAPTMS amount of the P（AA3-APEG1-Six）,the surface tension of the SC dilute solution decreased and the contact angle on the plant leaf surface decreased,they Showed better wettability.（4）The dispersion mechanism of P（AA3-APEG1-Six）in the suspension concentration was discussed by the characterization of the dispersibility in the suspension concentrate system. |
