阳离子化羟乙基纤维素醚的合成与溶液性质

以工业羟乙基纤维素(HEC)和N-(2,3-环氧丙基)三甲基氯化铵(GTA)为原料,在碱催化剂下干法制备不同取代度季铵盐型阳离子羟乙基纤维素醚。用均匀设计法优化合成条件,并通过蒙特卡罗模拟得到优化工艺条件,通过实验验证得到阳离子醚化试剂的反应效率达到85%以上,取代度达到0.49。同时探讨了阳离子羟乙基纤维素醚(QHEC)在不同介质中的黏性行为。结果表明,阳离子羟乙基纤维素醚在纯水中具有典型的聚电解质黏性行为,随着QHEC浓度减小,比浓黏度增大。同一QHEC质量浓度下,NaCl溶液中QHEC的比浓黏度总大于KCl溶液中QHEC的比浓黏度;随着外加盐NaCl溶液浓度的增大,其比浓黏度减小。     

阳离子纤维素醚的合成及流变性能研究

在自制碱催化剂存在下,工业羟乙基纤维素与N-(2,3-环氧丙基)三甲基氯化铵(GTA)阳离子化试剂反应,干法制备高取代度季铵盐型阳离子纤维素醚(CHEC)。用均匀实验方案考察了GTA与羟乙基纤维素(HEC)用量比、NaOH与HEC用量比、反应温度、反应时间对反应效率的影响,并通过蒙特卡洛蒙特卡罗模拟得到优化工艺条件,并通过实验验证得到阳离子醚化试剂的反应效率达到95%。同时探讨了其的流变性能。结果表明,CHEC的溶液呈现非牛顿流体特征,随着溶液质量浓度增大其表观粘度增大;在一定浓度的盐溶液中,CHEC表观粘度随着外加盐浓度的增大而减小。同一剪切速率下,CaCl2溶液体系中CHEC的表观粘度比NaCl溶液体系中CHEC的表观粘度大。     

取代均匀程度对羟乙基系列纤维素醚性能的影响

详细阐述了羟乙基系纤维素醚的取代均匀程度对纤维素醚自身(包括生物稳定性和稳泡性)和在乳胶漆中的应用(包括展色性荧光增白剂相容性)的影响,并介绍新一代甲基乙基羟乙基纤维素醚由于取代均匀而带来优越的性能表现。研究证明羟乙基系列纤维素中取代均匀程度的重要性并可帮助认识和选择合适的纤维素醚增稠剂。     

阳离子羟乙基纤维素溶液黏度性能的研究

以羟乙基纤维素（HEC）为原料,2-氯-4,6-二（N,N-二甲基-N-苄基1,3-丙二胺）1,3,5-均三嗪为改性剂,制备出不同取代度阳离子羟乙基纤维素。同时探讨了取代度及其浓度、阳离子及其浓度、转子转速、温度、pH值对阳离子羟乙基纤维素（CHEC）的黏性行为的影响。结果表明,阳离子羟乙基纤维素溶液黏度随着CHEC浓度增大、温度的升高、pH值的增加而减小。同一CHEC质量浓度下,取代度越高,转子的转速降低,黏度增大。CHEC在K₂SO₄溶液中的黏度总低于MgSO₄溶液中黏度;随着阳离子浓度的增加,CHEC溶液的黏度降低。     

羧甲基纤维素钠和羟乙基纤维素在日化产品中的应用

羧甲基纤维素钠(CMC)和羟乙基纤维素(HEC)是纤维素醚类产品中使用范围最广的产品,它们是纤维素链上葡萄酐单元的羟基与醚化基团(氯乙酸或环氧乙烷)反应而成的。其水溶液是非牛顿性流体,黏度随剪切速率变化而与时间无关。溶液的黏度随浓度增大迅速增加,是使用范围最广的增稠剂和流变助剂。介绍了CMC和HEC的分子结构、合成制备、溶液特性和在日化产品应用的配方。     

羟丙基纤维素的生产及应用

纤维素是自然界最丰富的可更新资源,自1973年世界上出现了石油涨价之后,再一次引起了人们的重视。 纤维素衍生物种类很多,一般可分为纤维素酯和纤维素醚两大类,纤维素醚又可分为离子型和非离子型。羟丙基纤维素(HPC)是国外继乙基纤维素(EC)、羟乙基纤维素(HEC)、羟乙基甲基纤维素(HEMC)之后工业化生产较早的非离子型纤维素醚之一。国外非离子型纤维素醚的生产和用量都很大,可广泛应用于建筑、石油开采、涂料、食品及食品包装,高分子合成、医药辅料等各个行业,其生产量约占纤维素醚总产量的一半左右,发展速度远远超过离子型纤     

N-月桂酰基-N′-羟乙基乙二胺乙酸盐的合成与性能研究

以月桂酸、羟乙基乙二胺和氯乙酸钠为原料合成N-月桂酰基-N′-羟乙基乙二胺乙酸盐(简称两性乙酸钠)表面活性剂,考察了其水溶液的表面化学性能和应用性能。得到两性乙酸钠的临界胶束浓度(cmc)为1.015×10-3mol/L,最低表面张力(γcmc)为26.34 mN/m,等电点为pH 4.21~7.88;以二苯甲酮为猝灭剂,用稳态荧光法测定体系的胶束聚集数(N),得8cmc时N为18。     

AM/AMPS/DMC聚两性电解质的合成、表征与溶液性能

以丙烯酰胺(AM)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)为原料,在0.5 mol/L NaC l溶液中,以2,2-偶氮二[2-(2-咪唑啉-2-代)丙烷]二氢氯化物(VA-044)为引发剂,合成了AM/AMPS/DMC系列聚两性电解质。利用13C NMR对共聚产物结构进行表征,结果表明,在高转化率情况下,共聚物组分与投料比基本一致。考察外加小分子电解质和温度对聚两性电解质溶液性能的影响,结果显示,阴、阳离子数量相近的聚两性电解质溶液的粘度随外加盐浓度增大而增大,在温度升高时,其表观粘度保留率高于聚丙烯酰胺,说明AM/AMPS/DMC系列聚两性电解质具有一定的抗温、耐盐能力。     

新发明

中国专利CN1087334A报道了一种新型两性表面活性剂及其合成方法。该表面活性剂的化学名称为;N-十二烷基-N-羟乙基-N-(甲酰胺基乙基)铵基乙酸盐。这种表面活性剂主要是从2-十一烷基-1-羟乙基-2-咪唑啉,经还原、甲酰化和季铵化制备而得。它在分子中引入了羟乙基,可使其水溶性得到改善;引入酰胺键,使其耐水解能力增强;同时,甲酰基还有抗静电、杀菌、防腐等性能。因而,这新型两性表面活性剂具有较好的综合性能。     

双(1-氯-N-羟乙基吗啉-2-羟丙基)正十八烷胺的缓蚀性能

采用失重法、极化曲线、电化学阻抗谱和原子力显微镜等分析方法研究了实验室自制的双(1-氯-N-羟乙基吗啉-2-羟丙基)正十八烷胺对A3钢的缓蚀性能,并探讨了其在钢片表面的吸附行为。失重法结果表明,双(1-氯-N-羟乙基吗啉-2-羟丙基)正十八烷胺在质量浓度为0.4g/L、温度为45℃时其缓蚀效果良好,缓蚀率达到91.32%,并且随着酸浓度的增大缓蚀率减小。极化曲线测试结果表明双(1-氯-N-羟乙基吗啉-2-羟丙基)正十八烷胺属于以抑制阴极为主的混合型缓蚀剂。双(1-氯-N-羟乙基吗啉-2-羟丙基)正十八烷胺分子在钢片表面的物理吸附行为符合Langmuir吸附等温式,是以化学吸附为主结合物理吸附的混合吸附;A3钢在盐酸溶液中的腐蚀反应过程是自发的、吸热的,并伴随着熵增。     

非电解质水溶液黏度的关联

许多化工过程的设计需要估算含水体系的黏度,但目前的黏度关联方法用于含水体系时误差较大.今以作者所在课题组近期提出的非水液体混合物黏度关联方程为基础,通过引入形状因子,得出了一个非电解质水溶液的黏度方程.该方程可用于二元非电解质水溶液黏度的关联,且能利用二元黏度得到的关联参数推算三元非电解质水溶液的黏度.该方程对54个二元非电解质水溶液体系黏度(总计2876个黏度数据点)关联的总平均相对偏差为4.60%;对7个三元非电解质水溶液体系黏度(总计352个黏度数据点)推算的总平均相对偏差为3.75%.结果表明,该方程具有较高的关联精度和推算精度.     

Polymeric and non-crosslinked acid self-thickening agent based on hydrophobically associating water-soluble polymer during the acid rock reaction

Different from traditional crosslinked polymer diverting agents, a polymeric and non-crosslinked acid self-thickening agent (ZPAM) based on hydrophobically associating water-soluble polymer of acrylamide (AM), [2-(methacryloyloxy)ethyl]trimethylammonium chloride (DMC) and N,N′-dimethyl octadecyl allyl ammonium chloride (DOAC) was synthesized. The apparent viscosity variation of ZPAM acid solutions in acid rock reaction and rheological properties of ZPAM spent acid solutions were studied. Results showed that ZPAM acid solutions demonstrated good uninterruptedly thickening ability from low apparent viscosity to high apparent viscosity during the acid rock reaction. Meanwhile, ZPAM spent acid solutions showed good shear resistance, viscoelasticity and high temperature resistance. The thickening mechanism of ZPAM acid solutions during the acid rock reaction was explained by apparent viscosity change, rheological properties of simulative ZPAM acid solutions, and ZPAM aqueous solutions with different concentrations of CaCl₂. The results showed increasing calcium chloride concentration enhanced the hydrophobic association strength of the thickener solution, resulting in increasing solution viscosity, in other words, the self-thickening agent showed excellent salt resistance and acid resistance. In addition, the change of association strength of ZPAM acid solutions during the acid rock reaction was further confirmed via environmental scanning electron micrographs and UV spectrum. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47907.     

Newtonian behaviour of sheared aqueous carboxymethylcellulose solution on aging

The effects of microbiological attack on the rheological properties of sodium carboxymethylcellulose (NaCMC) solutions are described. The effect of aging on the viscosity of aqueous NaCMC solution was studied by means of a Brookfield viscometer. An aqueous NaCMC solution was allowed to age and was subjected to shearing at different time intervals. Dilatant rheological properties were observed in contrast to the usually pseudoplastic behaviour of a normal NaCMC solution. This is attributed to the effect of shear-induced recombination of NaCMC macromolecular crystallites produced as a result of chain scission of NaCMC molecules during aging. The recombination of the crystallites gives higher values of viscosity at higher shear rates. A five months aged sample when subjected to shearing for a period of 20 h exhibits different behaviour. After prolonged post-shearing of this sample, the viscosity measured at shear speeds of 10 rpm and 20 rpm at 72 h and 102h approaches a common value for post-shearing period. The approach to the Newtonian character is attributed to the shear-stress-induced breakdown of the crystalline aggregates. These studies reveal that the aging effects on NaCMC solution have a drastic influence on the rheological properties.     

Aqueous solution properties of a poly(vinyl imidazolium sulphobetaine)

In this investigation the aqueous solution properties of an ampholytic poly(vinyl imidazolium sulphobetaine) are discussed. This class of polymer is water insoluble and its solubilization is related to the type and concentration of added salt. Cloud point determinations, intrinsic viscosity and light scattering studies are presented to illustrate the solution behaviour of this polyampholyte as a function of the type of cation and anion present. An explanation of its solubility in certain salt solutions is presented.     

Rheological properties of hydrophobically modified alkali-swellable acrysol emulsions

The rheological behaviour of aqueous solutions of two commercial anionic hydrophobically modified alkali-swellable emulsions (HASE), Acrysol TT615 and RM5, was studied. These polymeric systems, initially in the form of low-viscosity latices at low pH, tend to swell and increase their viscosity when neutralised with base. The steady-shear and dynamic properties of these polymers were measured over a wide range of concentration, at constant pH=9 and temperature of 20°C. The intrinsic and zero-shear viscosities were used to identify the concentration regimes of the polymer solutions. In the case of Acrysol TT615, the solution exhibited shear-thinning characteristics at a concentration above 500 ppm. The Carreau model described well the viscosity function of the 1000 and 2000 ppm solutions. Considerable viscosity enhancement and a change in the flow curve profile were observed at concentrations above 2000 ppm. At high polymer concentration. the zero-shear viscosity was not detectable, and the power law model was adequate to characterize these solutions. By contrast, the RM5 solutions exhibited nearly Newtonian behaviour over the whole concentration range considered. Elasticity measured from the first normal stress difference indicated that Acrysol TT615 was more elastic than Acrysol RM5. Dynamic measurements revealed that both storage (G′) and loss (G″) moduli increased with polymer concentration. In the higher frequency and concentration regions, G′ > G″ was obseved for TT615, whereas G″ > G′ for RM5.     

Viscometric study of aqueous poly(vinyl alcohol) (PVA) solutions as a binder in adhesive formulations

Commercial grade poly(vinyl alcohol) (PVA) is widely used in adhesive and textile industries. The density and viscosity of an aqueous PVA solution are important properties in the various processing stages in these industries. In this work, the density and viscosity of aqueous PVA solutions are measured and the average molecular weight of PVA is determined. The measured densities are expressed by a simple linear equation in terms of PVA weight fractions. The coefficients of the density equation are calculated and presented. The measured viscosities are fitted to the modified Eyring viscosity model developed by the authors and the parameters of the model are evaluated. The viscosity model with known parameters for aqueous PVA solutions has the added advantages that it can be used in practical applications in various industries for predicting viscosity of aqueous PVA solutions without recourse to expensive and time consuming experimental measurements.     

表面活性剂对十六烷基羟乙基纤维素溶液黏度的影响

通过流变仪研究了几种表面活性剂对十六烷基羟乙基纤维素(CHEC)溶液黏度的影响.结果表明,CHEC溶液的黏度随表面活性剂质量分数的增加先升高,达到最大值后逐渐下降;温度对表面活性剂和CHEC混合溶液黏度的影响与表面活性剂和CHEC形成的复合物有关;表面活性剂与CHEC的疏水缔合作用强弱顺序是AES>6501>CAB.     

Filler effect on the relaxation time of fibre suspensions in polymeric solutions

Viscosity measurements on suspensions of short glass fibres in aqueous solutions of poly(ethylene oxide) are presented. The volumetric filler fraction ranges between 0.01 and 0.07 and the shear rate from 0.1 to 1000 sec^?1. The results indicate that the filler enhances the non-Newtonian pseudoplastic behaviour of the suspending solution increasing its relaxation time. Furthermore, at low shear rate, in the region of Newtonian behaviour of the unfilled solutions, most of the suspensions show a viscosity increase with decreasing shear rate owing to fibre aggregate formation. These effects are compared with previously published results on glass bead suspensions in polymeric liquids.