三偏磷酸钠交联对羧甲基淀粉性能的影响

Effect of sodium trimethophosphate cross-linking on properties of carboxymethyl starch

以木薯淀粉为原料,三偏磷酸钠为交联剂,采用溶剂法“一步法”制备了交联羧甲基淀粉,研究了三偏磷酸钠交联对淀粉的溶胀性、特性黏度、分子量及其糊液的黏度、抗酸碱性能、耐温性能、抗剪切性能的影响。结果表明,交联改性降低了淀粉的溶胀性,提高了淀粉的特性黏度和分子量;适度交联能显著提高淀粉糊液的黏度、抗酸碱性能和耐温性能,抗剪切性能也得到有效改善。红外光谱分析(FTIR)证实了木薯淀粉发生了交联反应和羧甲基化反应;X-射线衍射分析(XRD)证实了木薯淀粉经羧甲基化后结晶度降低,交联羧甲基淀粉的结晶度略高于羧甲基淀粉;扫描电镜分析(SEM)证实了交联羧甲基化反应不仅发生在淀粉颗粒表面,也发生在淀粉颗粒内部。交联羧甲基淀粉综合性能优于羧甲基淀粉,可大大拓宽产品的应用范围。

Using cassava starch as raw material and sodium trimetaphosphate as crosslinking agent,cross-linked carboxymethyl starch was prepared by solvent method“one step”.The effects of sodium trimetaphosphate crosslinking on starch crosslinking degree,intrinsic viscosity,molecular weight,as well as the paste viscosity,acid-base resistance,temperature resistance and shear resistance were studied.The results showed that after cross-linking modification,the swelling property of starch was reduced and the intrinsic viscosity and molecular weight of starch were increased.After moderate cross-linking,the viscosity,acid-base resistance and temperature resistance of the starch paste can be significantly improved,and the shear resistance can also be effectively improved.The FTIR results showed that the crosslinking reaction and carboxymethylation reaction occurred in cassava starch.The XRD results showed confirmed that the crystallinity of cassava starch decreased after carboxymethylation,and the crystallinity of cross-linked carboxymethyl starch was slightly higher than that of carboxymethyl starch.The SEM results showed that the crosslinked carboxymethylation reaction not only occurred on the surface and inside of starch particles.The comprehensive performance of crosslinked carboxymethyl starch is better than carboxymethyl starch,which can greatly broaden the application range of the product.