十二叔胺改性瓜尔胶交联过程的流变性质

Crosslinking of Dodecyl Dimethyl Tertiary Amine Modified Guar Gum and Its Rheological Properties

为提高瓜尔胶交联凝胶的强度和流变性能,用十二叔胺和环氧氯丙烷对羟丙基瓜尔胶进行疏水改性,制得羟丙基瓜尔胶衍生物(DA-HPG)。用有机锆交联剂与改性前后的瓜尔胶交联,研究了基液质量分数、p H值、温度、剪切速率对交联过程的影响。结果表明,在实验范围内,剪切交联过程的稳态黏度随基液质量分数增大、温度升高、pH值增大、剪切速率减小而增大;0.3%DA-HPG适宜的交联条件为基液pH=10.8数11.0、温度30℃、0.2%交联剂加量。流变动力学模型可较好地描述交联过程。对改性前后的0.3%的瓜尔胶溶液及交联凝胶进行流变学测试,改性后体系的黏弹性、黏温性均有大幅提升,分子分解温度提高,结构更加稳定。

In order to improve the strength and rheological properties of crosslinked guar gum gels,a hydrophobic modified guar gum was developed and synthesized. Hydroxypropyl guar gum was hydrophobically modified with dodecyl dimethyl tertiary amine and epichlorohydrin to obtain hydroxypropyl guar derivative(DA-HPG). After crosslinking with organic zirconium crosslinker,the influences of concentration of solution,pH value,shear rate and temperature on the cross-linking process were investigated. The results showed that in the experimental range,the steady-state viscosity of the shear-crosslinking process increased with increasing concentration,pH value and temperature and decreasing shear rate. The preferred crosslinking condition for 0.3% DA-HPG was obtained as follows:pH 10.8数11.0,30℃,0.2% crosslinker. The crosslinking rheokinetics equation could well fit the cross-linking process. In addition,the rheological properties of 0.3% guar gum solution and crosslinked gel before and after modification were compared. The viscoelasticity and viscosity-temperature relationship were greatly improved,the molecular decomposition temperature increased and the structure was more stable after modification.