三异丙醇胺改性黄原胶溶液流变特性

Rheology of Triisopropanolamine Modified Xanthan Water Solution

为改善黄原胶的流变性能,采用三异丙醇胺与环氧氯丙烷合成多羟基阳离子醚化试剂,以此阳离子醚化试剂对黄原胶(XG)进行改性制得高黏度的多羟基两性黄原胶(TIPA-XG)。对XG及TIPA-XG进行了红外谱图、元素分析及XRD表征,研究并比较了TIPA-XG和XG溶液的流变特性,包括稳态黏度、流动曲线、触变性及黏弹性,并进一步研究了其耐温耐剪切性。结果表明,TIPA-XG溶液的黏度较XG显著增加,0.6%TIPA-XG溶液的黏度(320.45mPa·s)比XG溶液黏度(74.12mPa·s)增大了332%;XG和TIPA-XG溶液的流动曲线可用非线性共转Jefferys本构方程描述;TIPAXG溶液的黏弹性及触变性较XG溶液均显著提高;TIPA-XG溶液的耐温性能提高,80℃恒温剪切90min后,0.6%TIPA-XG的保留黏度(142.88mPa·s)为0.6%XG保留黏度(63.27mPa·s)的2.26倍,表明改性后TIPA-XG的耐温性能较XG而言有显著提升。

To improve the rheology of xanthan solution, a high viscosity polyhydroxy amphoteric xanthan (TIPA-XG) was developed through the etherization of xanthan polymer (XG). The etherizing agent used was a cationic polyhydroxy agent developed with triisopropanolamine and epichlorohydrin. The XG and TIPA-XG were characterized with IR spectroscopy, element analysis and XRD spectroscopy. The rheological characteristics of the TIPA-XG solution and the XG solution, including steady state viscosity, flow curve,thixotropy, viscoelasticity as well as the high temperature tolerance and shear resistance of the two solutions were studied and compared. It was found that TIPA-XG has higher viscosity than XG;the viscosity of a 0.6% TIPA-XG solution was 320.45 mPa·s, 332% higher than that of the XG solution, which was 74.12 mPa·s. The flow curves of the XG and the TIPA-XG solutions can all be described by the non-linear co-rotational Jeffreys constitutive equation. The viscoelasticity and thixotropy of the TIPA-XG solution were all greater than those of the XG solution. When sheared at 80 ℃ for 90 min, 0.6% TIPA-XG solution had a remaining viscosity of 142.88 mPa·s, which was 2.26 times of the remaining viscosity of the 0.6% XG solution (63.27 mPa·s) under the same conditions, indicating that TIPA-XG has better high temperature stability that XG.