瓜胶及其衍生物在药物控制释放领域的研究进展

介绍了官能团衍生化、接枝共聚、交联等瓜胶衍生物的制备方法及影响因素、瓜胶及其衍生物在药物控制释放领域的应用现状,并指出改性瓜胶具有比原粉更好的药物控制释放效果,因此经过配方设计,瓜胶及其衍生物有望成为药物控制释放尤其是靶向结肠给药领域的理想载体。     

羟丙基瓜儿胶

羟丙基瓜儿胶属高分子非离子表面活性剂,是由天然瓜儿胶经环氧丙烷改性的产品。本产品具有良好的交联性,充分考虑了分子量、取代度、交联性之间的关系,具有良好的性能。可用作化妆品及油田助剂,也可用作纺织印染助剂等。     

改性瓜胶压裂液的制备及性能研究

分别以十二烷基和磺酸盐甜菜碱为修饰基团,以瓜胶原粉为主剂,制备了2种改性瓜胶增稠剂:疏水改性羟丙基瓜胶和磺酸盐甜菜碱型瓜胶。模拟现场配方,对其配制的压裂液的抗剪切性能和耐温性能进行评价。通过对比发现磺酸盐甜菜碱型胍胶比油田提供CJ2-6胍胶耐温抗剪切能力有所下降,疏水改性羟丙基胍胶比油田提供CJ2-6胍胶耐温抗剪切能力有明显改善。其中,疏水改性羟丙基瓜胶80℃下剪切60 min后,表观粘度为93.4 m Pa·s,比油田提供CJ2-6瓜胶耐温抗剪切能力有明显改善。可以考虑疏水改性羟丙基瓜胶在压裂液体系的进一步应用。     

改性瓜胶压裂液的制备及性能研究

分别以十二烷基和磺酸盐甜菜碱为修饰基团,以瓜胶原粉为主剂,制备了2种改性瓜胶增稠剂:疏水改性羟丙基瓜胶和磺酸盐甜菜碱型瓜胶。模拟现场配方,对其配制的压裂液的抗剪切性能和耐温性能进行评价。通过对比发现磺酸盐甜菜碱型胍胶比油田提供CJ2-6胍胶耐温抗剪切能力有所下降,疏水改性羟丙基胍胶比油田提供CJ2-6胍胶耐温抗剪切能力有明显改善。其中,疏水改性羟丙基瓜胶80℃下剪切60 min后,表观粘度为93.4 m Pa·s,比油田提供CJ2-6瓜胶耐温抗剪切能力有明显改善。可以考虑疏水改性羟丙基瓜胶在压裂液体系的进一步应用。     

戊二醛接枝共聚改性骨胶粘合剂的研究

以戊二醛作为接枝改性剂制备改性骨胶粘合剂。研究了醛胶比、接枝温度和接枝时间等对改性骨胶粘合剂性能的影响,并采用红外光谱(FT-IR)和热失重分析(TGA)法对产物的结构与热稳定性进行了表征。结果表明:当醛胶比为0.2∶100、接枝温度为30℃和接枝时间为60 min时,所得改性骨胶粘合剂的剪切强度为10.7 MPa、凝胶温度为-2℃;此时产物的接枝效果明显,并具有良好的热稳定性能。     

瓜胶的疏水化改性研究

应用大分子反应法,用溴代十六烷作为疏水改性单体对天然瓜胶进行疏水化改性,制备疏水缔合瓜胶.研究了合成工艺条件对疏水缔合瓜胶粘度的影响.结果表明,用无水乙醇作分散剂,n(NaOH):n(C16H33Br):n(Guar)=0.506:0.05:1,反应温度60℃、反应时间8h制得疏水瓜胶综合性能较佳;疏水瓜胶与瓜胶水溶液的稳定性的比较结果表明疏水改性后样品溶液的稳定性大大提高.     

甜菜碱接枝共聚羟丙基瓜胶的制备

以羟丙基瓜胶和甜菜碱单体为原料,硝酸铈铵为引发剂,采用溶液聚合法制备甜菜碱接枝羟丙基瓜胶,对目标物结构进行了IR、质谱表征。考察了接枝反应温度、接枝反应时间、引发剂浓度、原料配比对目标产物增稠性能的影响,结果表明,当反应温度为20℃,引发剂浓度为5 mmol/L,反应时间为24 h,m(甜菜碱单体)∶m(羟丙基瓜胶)=1∶1时,单体转化率为36.5%,相对分子质量为1.28×10~6;常温下,配制目标产物质量分数0.5%的水溶液,20 min内充分溶解,初始黏度为75 m Pa·s;目标产物耐盐性优于羟丙基瓜胶,水溶性和增稠性良好。     

原位接枝改性炭黑补强NR结构与性能的研究

研究原位接枝改性炭黑补强NR的物理性能和动态力学性能,并分别采用热重分析仪、傅立叶红外光谱仪及转矩流变仪对原位接枝改性炭黑补强NR的结构进行表征和研究。结果表明,炭黑原位接枝改性后与橡胶界面的相互作用增强,硫化胶的性能提高,改性剂用量为4.5份时硫化胶的综合性能最好;改性剂与橡胶和炭黑发生了接枝反应,并参与了硫化。     

甲基丙烯酸固态原位接枝改性炭黑对天然橡胶和顺丁橡胶性能的影响

考察了固态原位接枝改性制备的甲基丙烯酸接枝改性炭黑对天然橡胶(NR)和顺丁橡胶。(BR)静态力学性能、动态力学性能的影响。结果表明。甲基丙烯酸改性炭黑比普通商品炭黑填充的NR硫化胶具有更好的静态力学性能;甲基丙烯酸改性炭黑曼有利于降低NR和BR硫化胶的滚动阻力。同时,有利于提高NR硫化胶的抗湿滑性。     

聚氨酯改性氯丁接枝低毒溶剂型鞋用胶粘剂的研制

研究了一种能粘多种材质的溶剂型鞋用大底胶。该胶为一种聚氨酯改性氯丁、SBS接枝胶,粘接范围广,对PU、TPR、SBS等材质粘接性能比氯丁接枝胶好,适合鞋厂流水生产线;所用溶剂毒性相当低,对人无害,有利于劳动保护和环境保护。     

干法制阳离子瓜尔胶

目前我国阳离子瓜儿胶工业化生产大都采用传统的湿法生产,湿法生产瓜尔胶存在需大量的有机溶剂,劳动强度大、能耗高、安全风险高、生产成本高等问题。本实验采用干法研制瓜尔胶,改变传统工艺,确定干法生产瓜尔胶最佳工艺配方及工艺条件,以确定产品最优成本,达到最大经济利益。     

瓜尔胶的化学改性

简要介绍了瓜尔胶的结构及其化学改性的原理和方法;综述了国内外瓜尔胶化学改性的研究工作;详细介绍了非离子瓜尔胶、阳离子瓜尔胶、阴离子瓜尔胶、羟烷基阴离子瓜尔胶和羟烷基阳离子瓜尔胶以及两性瓜尔胶的合成方法。瓜尔胶通过改性改善了水溶性、大大降低了水不溶物的含量、提高了电解质的兼容性、增加了黏度的稳定性、从而扩大了瓜尔胶的应用领域,使得改性瓜尔胶广泛应用于化妆品、个人护理品、造纸、油田和增稠剂等众多领域。     

Pentaerythritol encapsulated with boric acid: An efficient composite crosslinker for guar gum fracturing fluid

Commonly used crosslinker agents often have a low crosslinking efficiency with guar gum, the major component of fracturing fluid for crude oil recovery, and it often required a high loading of guar gum for achieving desired recovery from low-permeability reservoir. Nevertheless, a high-loading of guar gum might result in excessive residue and reduce the conductivity of the reservoir. Therefore, boric acid, a commonly used crosslinking agent, was introduced onto the surface of pentaerythritol to afford a composite crosslinking agent denoted as PB. The as-prepared PB crosslinker was characterized by Fourier-transform infrared spectrometry. The guar gum fracturing gel crosslinked with the PB had fantastic viscoelasticity and thermal stability and could reduce the guar gum loading by 16.7%, with boric acid as a control. Besides, the gel-broken liquid had good compatibility with the simulated water and caused reduced damage to rock core, showing potential for hydraulic fracturing of low-permeability reservoirs. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48528.     

Preparation and Sand-Fixing Property of a Novel and Eco-friendly Organic-Inorganic Composite

A novel guar gum/poly(acrylic acid)/loess (GG-g-PAA/loess) organic-inorganic composite used as chemical sand-fixing agent (CSFA) is successfully prepared in aqueous solution by polymerization guar gum (GG), neutralized acrylic acid (AA) and loess. The correlations between the content of prepared composite and the sand-fixing properties are investigated. The results show that the CSFA can significantly improve the compressive strength of the sand fixation specimens. Meanwhile, the sand fixation specimens have good thermal, freeze-thaw and UV-radiation aging stabilities to withstand the changes in temperature and strong UV radiation. Besides, the specimens treated with sand-fixing agent shows excellent water retention capacity.     

有机锆对羧甲基羟丙基瓜胶的交联性能研究

以氧氯化锆和柠檬酸等为原料,合成了适用于羧甲基羟丙基瓜胶在酸性条件下交联的有机锆交联剂,考察了pH值、温度、羧甲基羟丙基瓜胶和交联剂加量等对体系成胶时间的影响,评价了形成冻胶的抗温抗剪切性能、滤失性能和破胶性能.实验发现,在pH值为3.0时,羧甲基羟丙基瓜胶/有机锆体系具有可控的延缓交联特性,质量分数为0.5%和0.6...     

Synthesis of guar‐gum‐stabilized nanosized silver clusters with γ radiation

Gamma ray induced synthesis of Ag clusters in the aqueous medium has been carried out using natural polysaccharide guar gum as a stabilizer. The results showed that guar gum is very effective in binding the Ag clusters and restricts their size in the nano region. The surface plasmon resonance band in the wavelength range of 410–425 nm of visible region has confirmed the formation of Ag clusters. The size of the clusters is governed by the concentration of both, i.e. precursor Ag⁺ and guar gum. The clusters were characterized by TEM and XRD, which shows that the size of clusters is in the range of 10–30 nm. The results have shown that silver clusters stabilized by guar gum are stable in acid media and alkaline media is not a desired media for the synthesis. From thermogravimetric analysis it has been demonstrated that incorporation of nano sized Ag clusters within guar gum improves the thermal properties of irradiated guar gum. To the best of our knowledge, the use of guar gum as a stabilizer in the gamma ray induced synthesis of Ag nano clusters is being reported first time in the literature. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

羧甲基瓜尔胶絮凝剂的合成及其絮凝性能研究

以植物瓜尔胶为原料,采用半干法快速合成了羧甲基瓜尔胶,研究了合成反应温度、氯乙酸量、碱量等因素对其取代度的影响,得到了最佳合成工艺条件:瓜尔胶、氯乙酸、氢氧化钠的质量比为1.6∶1.2∶1,反应温度为70℃,反应时间为1h,室温搅拌20min。在最佳合成条件下,羧甲基瓜尔胶的取代度为0.51,黏度为3960mPa·s,采用红外光谱、热重分析等测试方法分析羧甲基瓜尔胶的结构及热稳定性,并将其应用于微污染水源水的强化处理工艺中,试验结果表明:羧甲基瓜尔胶对浊度的去除率可达90%以上。     

阳离子瓜尔胶粘度对头发梳理性的影响

以瓜尔胶为原料,3-氯-2-羟丙基三甲基氯化铵为醚化剂,氢氧化钠为催化剂,乙醇为溶剂,制备了阳离子瓜尔胶。利用头发梳理仪测定了洗发水中添加阳离子瓜尔胶前后,头发之间的摩擦力变化,考察了阳离子瓜尔胶对头发干、湿梳理性的影响,得出阳离子瓜尔胶能明显改善头发的梳理性:3300mPa.S以上粘度的阳离子瓜尔胶显示效果较佳。     

Preparation and evaluation of a cosmetic adhesive containing guar gum

Guar gum is an effective agent for use as a natural adhesive ingredient that can be used to replace the hazardous ingredients of spirit gum. This study describes the possibility of using guar gum as a renewable substituent for cosmetic adhesive. An adhesive base and cosmetic adhesive containing guar gum were prepared by a two-step process. The samples were tested for safety (cell toxicity test and patch test), stability (centrifugation, cycling and viscosity), and effectiveness (tensile strength). The results from the MTT assay show that the growth activity of human fibroblast skin cells was over 89% in all concentrations of cosmetic adhesive containing guar gum. In addition, no special skin reactions were reported in the patch test prepared adhesive containing guar gum. Moreover, the stability test demonstrated proper stability of all adhesive samples: the composition stability, heat stability, and viscosity of the adhesive samples maintained stable conditions. The efficacy test confirmed the superiority of the guar gum adhesive samples over spirit gum concerning the tensile strength. This study demonstrated that guar gum may be a viable replacement for synthetic rosins and also as a substituent in cosmetic.