Carboxymethyl starch (CMS) was produced from sago starch via carboxymethylation. The CMS with different degree of substitution (DS) ranges from 0.4 to 0.8 were mixed with polyethylene glycol (PEG) of different molecular weight and distilled water and the hydrogel was cured by electron beam irradiation with doses ranging from 25 to 35 kGy. The results revealed that CMS-PEG hydrogels with DS 0.4 give the optimum gel content when radiated at 30 kGy and with PEG 600. Thermogravimetric analysis (TGA) revealed that there are two phases exist in CMS with DS 0.4 in contrast to the three steps decomposition occurs in DS 0.6 and 0.8. It shows that the CMS with DS 0.4 is more thermally stable. Surface morphology revealed crosslinking among the blends when subjected into the radiation dose. The study shows both radiation and PEG addition improved most of the properties of CMS irrespective of the DS value.

羧甲基淀粉（CMS）是由西米淀粉经羧甲基化制得的。将具有0.4至0.8的不同取代度（DS）的CMS与具有不同分子量的聚乙二醇（PEG）和蒸馏水混合，并通过电子束辐照以25至35 kGy的剂量固化水凝胶。结果表明，当以30 kGy和PEG 600辐射时，DS 0.4的CMS-PEG水凝胶具有最佳的凝胶含量。热重分析（TGA）表明，DS 0.4的CMS中存在两相，而三步分解则相反在DS 0.6和0.8中出现。结果表明，DS 0.4的CMS具有更高的热稳定性。当经受辐射剂量时，表面形态显示共混物之间发生交联。