共查询到18条相似文献,搜索用时 78 毫秒
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田菁胶-水解聚丙烯酰胺体系的切稠特性吴启荣唐季安江龙(中国科学院感光化学研究所北京100101)田菁胶(SesbaniaGum)是由盛产于我国的一种豆科植物的种子提炼出来的一种非离子型半乳甘露聚糖胶,与国外报道的古尔胶(Guargum)的化学成分基本... 相似文献
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本文研究了黄原胶(XG)和瓜尔胶(GG)的混合溶液及其硼砂(B)交联体系的流变性,考察了XG/GG间的“协同增效作用”以及溶液组成、pH和电解质(NaCl和CaCl 2)对其流变性的影响。结果表明,所有溶液体系均为假塑型流体,其流变曲线可用Herschel-Bulkley和Casson模型描述。XG和GG复配具有明显的“协同增粘效应”,在XG占两聚合物的质量分数w(XG)为20%和90%时协同增粘效应最强,其“协同增粘率”(R m)分别约为42%和34%。硼砂(B)可交联XG/GG混合溶液,其交联增粘效果随w(XG)的减小和硼砂质量浓度ρ(B)的增大而增大;在w(XG)=50%和ρ(B)=1.00 g/L时,“交联增粘率”可达85%。在所研究的pH值范围(6.2~10.0)内,XG/GG混合溶液的流变性基本无变化,而XG/GG/B交联体系(w(XG)=50%和ρ(B)=0.75~1.00 g/L)的表观粘度随pH值增大先升高后降低,pH=9.0时出现最大值,交联增粘率达107%。电解质可使XG/GG/B交联溶液(w(XG)=10%和ρ(B)=0.50 g/L)体系的粘度大幅下降,且CaCl 2的影响明显高于NaCl,表明交联结构的耐盐能力较差。这些结果加深了对XG/GG混合溶液流变性的认识,可为其实际应用(如在强化采油中的应用)提供依据。 相似文献
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以钛酸四异丙酯、乳酸、甘油、三乙醇胺、硼酸、氢氧化钠为原料,合成了硼钛复合交联剂,表征了交联剂结构,制备了瓜尔胶压裂液,考察了中性条件下硼钛复合交联剂与压裂液形成冻胶的耐温耐剪切性能以及粘弹性,研究了冻胶的微观结构。室内实验结果表明:从核磁共振波谱推断出了硼钛复合交联剂的结构,通过交联剂粒径分布确定了硼钛复合交联剂的最佳合成工艺,该交联剂与瓜尔胶交联形成的冻胶,既有硼交联的粘弹性,又有钛交联的耐高温耐剪切性能,可在中性条件下实现有效的交联,为压裂返排液的再利用提供了有效的技术支撑。 相似文献
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利用环境扫描电子显微镜(ESEM)对粘度在5000mpa.s的高取代度羧甲基瓜尔胶及其降解产物的胶液微观结构进行了表征,并且与海藻酸钠胶液的微观结构相比,显示出不同程度的结构差异。这种结构差异导致其流变行为的差异。结果显示降解高取代度羧甲基瓜尔胶与海藻酸钠胶液的微观结构及流变性能接近,在物理性能和化学性能上较为符合活性染料印花糊料的要求。 相似文献
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以环氧氯丙烷和NaHSO_3为原料,Na_2SO_3为引发剂,乙二胺四乙酸二钠(EDTA-2Na)为络合增效剂,经酸催化开环反应合成了磺酸型两性表面活性剂中间体3-氯-2-羟基丙磺酸钠,然后在弱酸性条件下与胍胶通过醚化反应制备了磺酸基羟丙基胍胶,其结构经IR表征。通过正交实验确定了合成配方和条件的最优结果,研究了反应温度、pH、改性胍胶浓度对成胶后凝胶的表观粘度影响,并测试了最佳条件下制备的凝胶和对应稀溶液的流变性能。结果表明:氧氯化锆可有效交联改性胍胶,在pH为6、温度为70℃、改性胍胶浓度为0.6%的条件下制备的凝胶具有剪切变稀性质以及较好的粘弹性。 相似文献
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一种古老而又年轻的天然高分子—杜仲胶 总被引:12,自引:0,他引:12
本文简述了杜仲胶的开发史及资源情况。指出,杜仲胶高弹性体的出现,是其研究开发进入新阶段的标志。指出临界交联度是杜仲胶获得高弹性的关键概念。这种由有序柔性链组成的大分子网络,其高弹性不宜用分子链无规线团的贡献来解释,而是由于大分子网络的整体无序性。 相似文献
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Synthesis of Hydroxypropyl Guar Gum by Phase Transfer Catalysis 总被引:1,自引:0,他引:1
RongChunXIONG MingZhuCHANC JianMingCHEN NanZHOU GangWEI 《中国化学快报》2005,16(4):545-546
HGG (Hydroxypropyl guar gum) was synthesized by phase transfer catalysis for the first time. The effects of alkalinity, phase transfer catalyst, etherification, pH value, temperature,reaction time and stirring speed were investigated. An optimal synthetic reaction technology was established, namely, dose of guar gum is 100 g, propylene oxide 40-50 g, HTAC (hexadecyl trimethyl ammonium chloride ) 1.3-1.7 g, pH value 10-10.5, temperature 45-50~C, and reaction time 3-4 hours. The result shows that the improved HGG has high viscosity. Its dissolution speed, content of insoluble residue, colloid light transparency and stability are apparently superior to guar flour. 相似文献
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Pablyana L. R. Cunha Rondinelle R. Castro Francisco A. C. Rocha Judith P. A. Feitosa 《Macromolecular Symposia》2008,266(1):48-52
Summary: Commercial Guar Gum, a galactomannan polysaccharide, was purified by the use of two subsequent methods, including precipitation with Fehling solution in order to eliminate protein impurities. The protein content (3.6%) was totally removed. Glutaraldehyde cross-linked gels were prepared with purified (GGP) and unpurified gum (GGU). The viscosity of the gels is similar to that of Hylan G-F 20, a commercial substitute of hyaluronic acid, used in viscosupplementation in human osteoarthritis. Guar Gums (gel and solution) were injected intra-articularly into the knee joints of rats subjected to experimental OA and the effect in hypernociception and cells influx measured. GGU promoted hypernociception and cell influx in naïve rats. GGP was innocuous to naïve rats and inhibited hypernociception, both as a gel or solution, to the same extent as Hylan G-F20. GGP promotes analgesia in OA due to its carbohydrate component. 相似文献
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《高分子科学杂志,A辑:纯化学与应用化学》2013,50(8):1085-1094
Guar gum was chemically modified by sulphonation using chlorosulphonic acid (ClSO3H) as a reagent. Effects of molar ratio of ClSO3H to glucopyranosic unit (ClSO3H/GU), reaction time and reaction temperature on the degree of sulphonation (DS) and molecular weight (Mw) of products were studied. The structures of guar gum sulphate were investigated by GPC, FT‐IR and UV‐Visible spectroscopy. Activated partial thromboplastin time (APTT) assay showed that the guar gum sulphate could inhibit the intrinsic coagulant pathway. The anticoagulant activity strongly depended on the DS and Mw of polysaccharides. DS>0.56 was essential for anticoagulant activity. The guar gum sulphate with the DS of 0.85 and the Mw of 3.40×104 had the best blood anticoagulant activity. 相似文献
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建立了微波消解-石墨炉原子吸收法测定瓜尔豆胶中铅的方法。探讨了样品的称样量及前处理条件、基体改进剂的选择以及仪器工作条件的优化。铅的线性范围为0~40.0μg/L,相关系数r=0.9996,方法的检出限为0.63μg/L,测定结果的相对标准偏差为1.32%~2.16%(n=6),加标回收率为90.3%~99.4%。该法准确、简单、灵敏度高,重现性好。 相似文献
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The anionic, cationic and nonionic polymeric flocculants endowed with several distinguished characteristics are being increasingly applied for the treatment of industrial effluents, municipal and wastewater. For the treatment of highly negatively charged particle suspensions, cationic flocculants are more efficient. A new route to guar gum derivatives bearing cationic groups has been developed. A series of cationic guar gums (Cat GG) have been developed by incorporating a cationic moiety N- (3- Chloro-2- hydroxypropyl) trimethyl ammonium chloride (CHPTAC) onto the backbone of guar gum in presence of NaOH. The various grades of cationic guar gum have been characterized by elemental analysis, FTIR spectroscopy and intrinsic viscosity measurement. The flocculation characteristics of these cationic guar gums have been evaluated in silica suspension by jar test. It has been found that among the various grades of cationic guar gums, the one with longer CHPTAC chains shows better performance. The flocculation characteristics of this best performing cationic guar are compared with those of various commercially available flocculants in silica suspension. Their rheological investigations have also been undertaken. 相似文献
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G. Panariello R. Favaloro M. Forbicioni E. Caputo R. Barbucci 《Macromolecular Symposia》2008,266(1):68-73
Summary: Guar gum (GG) polymer was crosslinked in order to obtain a new hydrogel. The GG hydrogel has been characterized by means of FT-IR spectroscopy, the determination of the water content, at different pH values, rheological measurements and in vitro release studies. The GG hydrogel shows a maximum water uptake at acid and basic pH values. The mechanical properties are investigated in order to verify the thixotropic behaviour of the material. In vitro release studies are conducted to evaluate the application of the GG hydrogel as a matrix for controlled drug release. 相似文献