基于动态硼酸酯键改性黄原胶的性能

基于苯硼酸聚合物可以与存在于黄原胶糖环单元结构中的伯、仲醇羟基通过硼酸酯键形成动态共价微交联结构的性质对黄原胶进行改性。以偶氮二异丁基脒二盐酸盐（AIBA）为引发剂，通过水相自由基聚合，制备了不同共聚比的丙烯酰胺（AM）、N-(3-二甲氨基丙基)丙烯酰胺（DMAPAM）和3-丙烯酰胺基苯硼酸（AMBB）的三元共聚物P(AM-co-DMAPAM-co-AMBB)。通过1H NMR、FTIR、元素分析和光散射对聚合物结构及相对分子质量进行了表征，并对其与黄原胶复配体系的增黏性、流变性、抗老化性及抗干扰性进行了评价。结果表明：P(AM-co-DMAPAM-co-AMBB)与黄原胶复配后对黄原胶溶液具有明显的增黏性，其中苯硼酸单体的摩尔比为1.0 mol%的聚合物对黄原胶溶液的增黏幅度达43.8%，在8074 mg/L的矿化水中增黏幅度高达56.4%，且复配体系具有良好的抗老化降解性，对乙二醇和1,3-丙二醇具有较强的抗干扰性。

Properties of modified xanthan gum based on dynamic borate ester bond

Benzeneboronic acid polymer can form micro-crosslink net with xanthan gum through dynamic borate ester bond between benzeneboronic acid and diol of xanthan gum, and the ability can be applied in the chemical modification of xanthan gum. Ternary copolymers P(AM-co-DMAPAM-co-AMBB) with various copolymerization ratios were synthesized via aqueous free radical polymerization of acrylamide (AM), N-(3-dimethylaminopropyl)acrylamide (DMAPAM) and 3-acrylamide benzene boric acid (AMBB) using 2,2''-azobis2-methylpropionamidine] dihydrochloride (AIBA) as initiator. The structure and molecular weight of ternary copolymers were characterized by 1H NMR, FTIR, elemental analysis and light scattering technique, and the thickening, rheology, aging resistance and anti-interference properties of the composite system of ternary copolymers and xanthan gum were evaluated. The composite system of P(AM-co-DMAPAM-co-AMBB) and xanthan gum exhibited good tackify performance: the viscosity of the composite solution of the ternary copolymer with the molar ratio of AMBB equal to 1.0 mol% and xanthan gum increased by 43.8% in pure water and 56.4% in mineralized water (8074 mg/L). Besides, the composite system exhibited good aging resistance in pure water and mineralized water and good anti-interference to glycol and 1,3-propanediol.