以羧甲基淀粉（CMS）为原料，丙烯酰胺（AM）为接枝单体，制备了羧甲基淀粉丙烯酰胺接枝共聚物（CMSGAM），并以粘度为测试指标，通过单因素实验和正交实验优化制备工艺。研究过程中采用傅里叶红外光谱（FT-IR）、扫描电镜（SEM）和热重分析仪（TG）对CMSGAM进行表征，对CMSGAM的粘度、透明度、抗盐性、凝沉性和保水性等理化性质进行了测试。结果表明：制备的最佳工艺条件为pH=7.5，反应温度50 ℃，反应时间3 h，在此条件下制备得到的CMSGAM糊液最大粘度为26000 MPa·s；红外光谱图谱显示1667 cm-1处出现酰胺基团中羰基伸缩振动吸收峰，1455 cm-1处出现酰胺基C-N键的伸缩振动吸收峰，热重分析图谱显示350~450 ℃出现了丙烯酰胺基团的热分解阶段，证明羧甲基淀粉中已成功接入了丙烯酰胺基团；扫描电镜照片显示CMS颗粒出现了大量孔洞和破碎现象，说明接枝共聚反应剧烈，破坏了淀粉颗粒结构；CMSGAM糊液的粘度和透明度均提升至CMS的4倍以上，抗凝沉性和热稳定性均比CMS高，但抗盐性的提升不明显。

Carboxymethyl starch-graft-acrylamide copolymer (CMSGAM) was prepared by using carboxymethyl starch (CMS) as the raw material and acrylamide (AM) as the monomer for grafting. The preparation process was optimized through single factor and orthogonal experiments by using the viscosity of the CMSGAM paste as the index. Characterization of the CMSGAM was performed using fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermogravimetric analyzer (TG). The physical and chemical properties of CMSGAM such as viscosity, transparency, salt resistance, coagulation and water retention were determined. The results showed that the optimum conditions for the preparation were: pH 7.5, reaction temperature 50 ℃, and reaction time 3 h. Under such conditions, the viscosity of CMSGAM paste was the highest (26000 MPa·s). In the FT-IR spectra, a absorption peak near 1667 cm-1 was found (which reflected the characteristic stretching vibration of carbonyl residue in the amide group), along with the absorption peak near 1455 cm-1 (which corresponded to the characteristic vibration of C-N bond in the amide group). The thermalgravimetric analysis revealed the thermal decomposition of the acrylamide group from 350 ℃ to 450 ℃, which proved the success of grafting the acrylamide group into the carboxymethyl starch. The SEM images showed a large number of pores and fractures on the CMS particles, indicating that the graft copolymerization reaction was severe and the structure of starch granule was destroyed. The viscosity and transparency of the CMSGAM paste increased more than 4 times, along with higher anticoagulation effect and thermal stability and minimally improved salt resistance, compared to the CMS paste.

广州市对外科技合作项目（201508030020）