Abstract: The thickening agent of graft copolymer was synthesized by carboxymethyl starch (CMS) and acrylamide (AM) under the condition of initiator. The optimum synthesis conditions were investigated by orthogonal experiment design. The structure of the product which was obtained under the best reaction conditions was characterized by FT-IR, and the salt sensitivity and temperature stability, shear stability and anti-ageing of the graft copolymer solution in different slurry were measured by rotational viscometer. The results show that the viscosity can reach 280 mPa·s under the reaction conditions as follows: the reaction temperature 60 ℃, the reaction time 7 h, the mass ratio of CMS to AM 1∶6 and the initiator addition amount 0.9%. The CMS-AM graft copolymer in different slurry shows excellent the salt sensitivity and temperature stability, shear stability and anti-ageing, which can satisfy the needs of oil field fracturing fluid for thickening agent.

Key words: Graft starch , Graft polymers , Thickening properties , Fracturing fluid

摘要：  以羧甲基淀粉（ＣＭＳ）与丙烯酰胺（ＡＭ）为原料，在使用引发剂的条件下合成聚合物增稠剂。通过正交实验设计确定了最佳合成工艺条件，利用傅里叶转换红外光谱（ＦＴ－ＩＲ）测定产物结构，采用旋转粘度计测定了接枝聚合物在不同泥浆中的耐温耐盐性、抗剪切性、抗老化性。结果表明：在反应温度６０℃、反应时间７ｈ、ＣＭＳ与ＡＭ 质量比１∶６、引发剂质量分数为０．９％的条件下，ＣＭＳ－ＡＭ 接枝聚合物的粘度可达２８０ｍＰａ·ｓ以上；ＣＭＳＡＭ接枝聚合物在不同泥浆中的耐温耐盐性、抗剪切性、抗老化性达到良好的结果，可以满足油田水基压裂液对增稠剂的需求。

关键词: 接枝淀粉 , 　接枝聚合物 , 　增稠性 , 　压裂液