分子结构对水解AM/DMDAAC聚合物流变性能的影响

Effects of Molecular Structure on Rheology of Hydrolyzed Poly(AM/DMDAAC)

摘要:

为研究分子结构对两性离子聚合物流变性能的影响方式，以丙烯酰胺（AM）和二甲基二烯丙基氯化铵（DMDAAC）为单体，进行自由基共聚，随后对共聚产物进行水解，制得了9个具有不同特性黏数、阴离子度和阳离子度的两性离子聚合物-部分水解聚AM/DMDAAC（HPAD-1，HPAD-2，HPAD-3，HPAD-4，HPAD-5，HPAD-6，HPAD-7，HPAD-8，HPAD-9）。通过IR、1HNMR、滴定法和乌氏黏度计表征了聚合物的结构参数。用旋转黏度计和流变仪分别考察了HPAD溶液表观黏度和剪切稀释行为。实验结果表明：HPAD的特性黏数与溶液表观黏度、剪切稀释性正相关。随着特性黏数由182.03 mL/g升至555.08 mL/g，质量分数0.75%的HPAD溶液表观黏度由12.1 mPa•s（HPAD-9）增至766.5 mPa•s （HPAD-7）。HPAD的阴离子度和阳离子度与溶液表观黏度负相关，对剪切稀释性影响较小。当阴离子度从29.98 mol%增至51.75 mol%，质量分数0.2%的HPAD溶液表观黏度从111.1 mPa•s（HPAD-1）降至21.5 mPa•s（HPAD-4）。阳离子度为10.31 mol%的HPAD-2和阳离子度为6.88 mol%的HPAD-8在5 s-1至100 s-1范围内的剪切稀释曲线几乎重合。

Abstract:

To study the influence of polyampholyte’s molecular structure on its rheology, the copolymers of acrylamide (AM) and diallyl dimethyl ammonium chloride (DMDAAC) were synthesized via free radical copolymerization, and then were hydrolyzed with NaOH to produce nine polyampholyte-hydrolyzed poly(AM/DMDAAC) (abbreviated by HPAD-1, HPAD-2, HPAD-3, HPAD-4, HPAD-5, HPAD-6, HPAD-7, HPAD-8 and HPAD-9) with varied intrinsic viscosity, anionicity and cationicity. These polymers were characterized by IR, 1H NMR, titration and Ubbelohde capillary viscometer. The apparent viscosity and shear thinning behavior of HPAD solution were studied by using rotational viscometer and rheometer, respectively. The results revealed that HPAD’s intrinsic viscosity was in a positive correlation with both its solution viscosity and shear thinning effect. The apparent viscosity of 0.75% HPAD solution (mass fraction) increased from 12.1 mPa•s (HPAD-9) to 766.5 mPa•s (HPAD-7) when the intrinsic viscosity grew from 182.03 mL/g to 555.08 mL/g. The anionicity and cationicity of HPAD were negatively correlated with solution viscosity, and had little influence on shear thinning behavior. The apparent viscosity of 0.2% HPAD solution (mass fraction) decreased from 111.1 mPa•s (HPAD-1) to 21.5 mPa•s (HPAD-4) when the anionicity enhanced from 29.98 mol% to 51.75 mol%. HPAD-2 and HPAD-8 with cationicity of 10.31 mol% and 6.88 mol% respectively, had almost coincided shear thinning curves in the range of 5 s-1 to 100 s-1.