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采用控制应力流变仪研究了聚合物分散剂苯乙烯丙烯酸无规共聚物(MOTAS)用量、分子量及氟铃脲质量分数等对氟铃脲水悬浮剂流变性质的影响.结果表明,以聚合物MOTAS为分散剂制备的氟铃脲水悬浮剂的流变行为符合Herschel-Bulkley模型.在固定氟铃脲质量分数为20%时,当分散剂质量分数≤3.0%时,流动行为指数n≤1.0,悬浮体系表现为假塑性流体,当分散剂质量分数≥3.5%时,流动行为指数n≥1.0,悬浮体系具有胀塑性流体特征.氟铃脲水悬浮剂的流变参数屈服值τ_H与分散剂MOTAS和氟铃脲的加入量有关.分散剂MOTAS质量分数≤2.5%时,分散剂在氟铃脲颗粒界面吸附很少,裸露的氟铃脲颗粒界面间相互搭接,具有较大的屈服值τ_H;当分散剂加入质量分数为3.0%时,分散剂可在氟铃脲颗粒界面形成饱和吸附,若再增加分散剂用量,多余分散剂在悬浮的氟铃脲颗粒间形成搭接,使其屈服值τ_H增大.在MOTAS分散剂的分子量在10 000～30 000范围内时,MOTAS分子量愈大,所制得的氟铃脲水悬浮剂的表观粘度和屈服值τ_H愈小,流变行为指数n虽略有增加,但均小于1,没有改变"剪切变稀"的假塑性特征.

The rheology of hexaflumuron in the form of aqueous suspension concentrate(SC) was studied by means of controlled stress rheometer, with the particular emphasis on the effects of polymer dispersant MOTAS(Styrene-acrylic acid random copolymer)mass concentrations, molecular mass and hexaflumuron mass concentrations. It was found that the rheological behavior of hexaflumuron SC, which contained MOTAS, coincided with the Herschel-Bulkley rheological model. For a hexaflumuron mass concentration of 20%, the SC was pseudoplastic fluid and the flow behavior index n≤1.0 when the MOTAS mass fraction was less than 3.0%; the SC was bulging plastic fluid and the flow behavior index n≥1.0 while the MOTAS mass fraction was more than 3.0%. The yield value τ_H of hexaflumuron SC was correlated with the relative mass fractions of MOTAS and hexaflumuron. Little MOTAS was adsorbed on the hexaflumuron granule surface in its concentration≤2.5%, and the uncoverd granules were connected with each other in some structures, which resulted in the biggist τ_H. When MOTAS mass fraction was 3.0%, saturated adsorption was achieved on the granule surfaces. The excessive MOTAS connected with each other in some structures, which produced the biggist τ_H likewise. Between dispersant MOTAS molecular mass 10 000 and 30 000, with the increase of MOTAS molecular mass, the viscidity and yield value τ_H of hexaflumuron SC decreased, while the flow behavior index n increased slightly .The n values were all less than 1, and the property of "shear thinning" of the pseudo-plasticity was not changed.