Adsorption of sodium polyacrylate at interface of dicalcium silicate-sodium aluminate solution

The adsorption isotherm of sodium polyacrylate on dicalcium silicate（2CaO-SiO2） in sodium aluminate solution at 80 ℃ was studied.The type of surface adsorption of sodium polyacrylate is saturated adsorption,and the adsorption behavior belongs to L-type,according with the monolayer adsorption model of Langmuir equation.The surface coverage of sodium polyacrylate is 1.06 mol/μm2.The relation curve between the surface pressure and the molecular area of adsorption film was obtained by Gibbs formula.The variation of interfacial energy caused by adsorption as well as the relationship between the relation curve and the type of adsorption was discussed.

SYNTHESIS AND APPLICATION OF NEW DETERGENT BUILDER POLYACRYLATE SODIUM

The low molecular weight polyacrylate sodium (PAA Na) detergent builder was synthesized with K 2S 2O 8 as initiator in a neutral aqueous medium. The influences of reaction conditions on the viscosity average molecular weight were studied. The critical value of synthetic PAA Na inhibiting the precipitation of CaCO 3 was determined and compared with that of other common builders. It is confirmed from SEM graphs that PAA Na can make CaCO 3 crystal defective. Washing tests show synthetic PAA Na can partially replace sodium tripolyphosphate (STPP) and is a potential polymeric detergent builder in low phosphate powder detergents.

Determination of Ni^(2+) in Waters with Sodium Polyacrylate as a Binding Phase in Diffusive Gradients in Thin-films

An aqueous solution containing sodium polyacrylate（PAAS） was used in diffusive gradient in thin-films technique（DGT） to measure DGT-labile Ni2＋ concentrations.The DGT devices（PAAS DGT） were validated in four types of solutions,including synthetic river water containing metal ions with complexing EDTA or that without complexing EDTA,natural river water（Ling River,Jinzhou,China） spiked with Ni2＋,and an industrial wastewater （Jinzhou,China）.Results show that only free metal ions were measured by PAAS DGT,recovery=97.36% in the solutions containing only free metal ions,recovery=49.62% in a solution with metal/EDTA molar ratio of 2：1 and recovery=0 in the solutions with metal/EDTA molar ratios of 1：1 and 1：2.These indicated that the complexes of Ni-EDTA were DGT-inert.The DGT performance in spiked river water（recovery=18.24%） and in industrial wastewater（recovery=12.25%） were investigated,which indicated that the measurement of metals by this DGT device did not include the humic substances complexed fractions of metals.The binding properties of PAAS DGT for Ni2＋ were investigated under different conditions of pH value and ionic strength.Conditional stability constants（lgK） of PAAS-Ni complexes were also evaluated.

High-strength and self-degradable sodium alginate/polyacrylamide preformed particle gels for conformance control to enhance oil recovery

Excess water production has become an important issue in the oil and gas extraction process.Preformed particle gels(PPGs),show the capability to control the conformance and reduce excess water cut.However,conventional PPGs have poor mechanical properties and their swollen particles are easily damaged by shearing force when passing through the fractures in formations,meanwhile PPGs can be also degraded into various byproducts,leading to permanent damage to the reservoir permeability after temporary plugging.Herein,a novel type of dual cross-linked PPGs(dPPGs)was designed and synthesized using sodium alginate(SA)and acrylamide(AAm),cross-linked with N,N’-methylenebisacrylamide(MBA)and Fe^(3+).Results show that dPPGs have excellent mechanical properties with a storage modulus up to 86,445 Pa,which is almost 20 times higher than other reported PPGs.Meanwhile,dPPGs can be completely degraded into liquid without any solid residues or byproducts and the viscosity of dPPGs degraded liquid was found to be lower than 5 mPa·s.A laboratory coreflooding test showed that the plugging efficiency of dPPGs was up to 99.83%on open fractures.The obtained results demonstrated that dPPGs could be used as economical and environment-friendly temporary plugging agent with high-strength,self-degradation,thermal stability,and salt stability,thus making it applicable to a wide range of conformance control to enhance oil recovery.

聚丙烯酸钠改性红黏土工程特性试验研究

为研究聚丙烯酸钠改性红黏土的工程特性,利用聚丙烯酸钠对柳州重塑红黏土进行固化处理,开展变水头渗透试验和三轴剪切试验,分析改性红黏土的渗透特性和力学性能,确定聚丙烯酸钠的最适掺量,并通过对最适改性土开展崩解试验和扫描电镜试验,确定改性红黏土的抗崩解性能,揭示聚丙烯酸钠改性红黏土的微观作用机理。结果表明:随聚丙烯酸钠掺量的增加,改性土的渗透系数呈现逐步下降的趋势,并在达到3%后逐渐趋于稳定,此时渗透系数为8.1379×10^(-7)cm/s,相对素红黏土降低了90.78%;而改性红黏土的抗剪强度呈现先增大后减小的趋势,并在2%时达到峰值,相对素红黏土提高了394.21%。综上确定聚丙烯酸钠的最适掺量为3%,此掺量下改性土的抗崩解性能提高了42.86%,土颗粒间的孔隙被聚合物链所填充,碎散的颗粒状红黏土变为连续状,排列结构与致密程度均优于素红黏土。经聚丙烯酸钠改性后,红黏土的防渗性能、力学性能与抗崩解性均存在明显提高,可以为实际工程提供理论指导。

沙蒿胶复配聚丙烯酸钠对马铃薯湿粉条品质的影响

以马铃薯淀粉为主要原料,添加沙蒿胶和聚丙烯酸钠制备无矾湿粉条。以感官评分、断条率、糊汤率、硬度和弹性为指标,通过正交试验确定最优配方,同时探究沙蒿胶和聚丙烯酸钠对湿粉条糊化、流变、热学特性和微观结构的影响。结果表明:以总淀粉质量为基准,添加0.7%沙蒿胶和0.3%聚丙烯酸钠复配制得的粉条品质接近对照组(明矾),与添加单一亲水胶体的粉条相比,其黏度增加,老化程度提高,凝胶网络结构增强,且具有均匀的片层孔状结构。

海藻酸钠包埋污泥颗粒的耐磨性能研究

为了探究海藻酸钠(SA)包埋颗粒耐磨性的影响因素,以SA包埋活性污泥颗粒为研究对象,探究了SA添加量以及不同包埋强化剂对颗粒耐磨性能的影响。结果表明:增加SA添加量制备颗粒污泥的耐磨性能也随之增强,但是当添加量高于2.0%(质量分数)时,耐磨性能增强效果不明显;颗粒耐磨性能增强对于水样的电导以及COD没有明显的影响;单独添加羧甲基纤维素(CMC)、卡拉胶等包埋强化剂不能增加颗粒的耐磨性,聚丙烯酸高吸水树脂(PA)、聚乙烯吡咯烷酮-K30/-K90会降低颗粒的耐磨性;CMC/PA、卡拉胶/PA的复合添加对颗粒耐磨性能有显著的增强作用,卡拉胶/PA的组合增强效果略优于CMC/PA,且增加卡拉胶的添加量对颗粒的耐磨性有增强作用。

聚丙烯酸钠的制备及性能研究

通过操作简便、应用广泛的水溶液聚合法,制备了粘均分子量约为1500~3000聚丙烯酸钠。研究表明,聚丙烯酸钠的相对分子量随着引发剂用量以及链转移剂用量的增加而减小。相应聚丙烯酸钠(分子量为2000)的减水率达到22.8%,高于市场常用萘系减水剂,表现出优异的应用潜力。

钠基蒙脱土改性聚丙烯酸树脂基吸附剂的制备与性能

以丙烯酸(AA)、丙烯酰胺(AM)为共聚单体,钠基蒙脱土(Na-MMT)为改性剂,采用反相悬浮聚合法,制备钠基蒙脱土改性聚丙烯酸树脂基吸附剂。在钠基蒙脱土用量为单体总质量的6%,温度75℃,单体比例AA∶AM为4∶1(质量比),搅拌速度350 rpm,引发剂(APS)用量为单体总质量的1%和交联剂(MBA)用量为单体总质量的0.25%的优化条件下,所制备的钠基蒙脱土改性聚丙烯酸树脂基吸附剂对重金属离子Pb^(2+)、Cu^(2+)的吸附量分别为292.6 mg/g和178.9 mg/g。

基于统计分析筛选适用于凝胶贴膏的聚丙烯酸钠(部分中和)关键质量属性

目的:考察不同厂家聚丙烯酸钠(部分中和)的理化性质,分析其关键质量属性,并探讨这些属性与凝胶贴膏性能指标之间的关系,为筛选适用于凝胶贴膏的辅料提供参考。方法:对三个厂家六个型号样品进行理化性质表征,采用统计分析筛选关键质量属性。选择两个型号制备凝胶贴膏,评估其对黏附力和体外释放度的影响,并用随机森林模型验证关键质量属性的影响。结果:不同厂家样品理化性质存在差异。筛选了六个关键质量属性:黏度、粒径D90、pH值、低聚物、丙烯酸残留单体和干燥失重。随机森林模型验证这些属性对贴膏性能有显著影响。结论:已识别的六个关键质量属性是影响样品理化性质和凝胶贴膏性能的主要因素。通过优化这些关键属性,优化这些属性可提高贴膏的黏附性能和药物释放特性。本研究提供了一种基于统计分析的方法,识别聚丙烯酸钠(部分中和)关键质量属性,但由于样本量较小,存在一定的局限性,未来还需要在更大范围内进行验证。

Influence of Suspension Parameters on Water Absorbency of Starch-g-poly( sodium acrylate) Synthesized by Inverse Suspension Polymerization

Superabsorbents starch grafted sodium polyacrylate was prepared by inverse suspension polymerization, using toluene as the continuous phase, potassium persulfate as the initiator. The effect of suspension parameters, such as volume ratio of continuous phase and dispersed phase, type and dosage of suspending agents, on water absorbency of the starch grafted polymer was studied. Different starch derivatives were also investigated. Superabsorbents made of cationic starch has higher water absorbency than that made of native corn starch.

聚丙烯酸钠对聚丁二酸丁二醇酯水解性能的影响

采用熔融共混法制备了聚丁二酸丁二醇酯/聚丙烯酸钠(PBS/PAAS)共混物,探究PAAS对PBS水解性能的影响。通过吸水率和失重率分析了共混物的水解性能,利用拉力试验机、差示扫描量热、扫描电镜和X射线衍射仪等对共混物的力学性能及水解前后结晶性能、微观形貌和结晶结构进行表征。结果表明,随PAAS用量的增大,共混物基体孔洞增多,水解性能有较大提升。当PAAS用量为100份时,共混物的吸水率最高为110.1%,水解失重率为44.6%;加入PAAS后,共混物的拉伸强度、屈服强度和断裂伸长率降低,弹性模量升高。PAAS可以提高共混物的结晶温度,但对熔融温度影响不大,随水解时间的延长,共混物的熔融温度没有发生变化,但PBS组分的熔融焓变化明显。同时,水解过程中共混物中PBS的晶型没有变化。

膨润土与聚丙烯酸钠混合料改良湿陷性黄土试验研究

为进一步探究膨润土与有机材料聚丙烯酸钠改良湿陷性黄土力学特性,解决黄土不良特性等问题,将不同掺量的混合料掺入到黄土中进行无侧限抗压强度、湿陷性和渗透性试验,并利用SEM进一步分析膨润土与聚丙烯酸钠材料改良黄土机理。试验结果表明,无侧限抗压强度随混合料掺量呈先上升后下降趋势,最大无侧限抗压强度达到837kPa;膨润土与聚丙烯酸钠有机材料处理后的重塑黄土湿陷系数显著下降,且湿陷系数均小于0.015;随混合料掺量的增加,渗透系数呈先下降后上升趋势,不同掺量混合料黄土(w2、w3、w4、w5)较素黄土(w1)渗透系数分别下降19.5%、44.9%、57.5%、54.0%;SEM图像显示,过量混合料掺量将导致黄土内部孔隙变大,进一步降低黄土无侧限抗压强度、湿陷性和渗透性。试验结果可为黄土加固提供参考依据。

四种胶体在鱼肉丸中的应用性研究

以冷冻肉制品中的代表性产品鱼肉丸为研究对象,使用国产淡水鲢鱼糜,对比添加不同浓度卡拉胶、魔芋粉、海藻酸钠、聚丙烯酸钠后鱼肉丸肉馅的pH、出品率和速冻后鱼丸的白度、质地结构方面的差异。结果表明,添加聚丙烯酸钠可以提高肉馅的pH以及产品的白度;添加魔芋粉和海藻酸钠时,pH、质地结构、口感口味差异不明显;添加卡拉胶可以提升鱼丸的弹性。总体来说,同时使用0.30%卡拉胶、0.20%魔芋粉、0.20%聚丙烯酸钠可显著改善鱼丸的品质。对提升以国产淡水鱼糜为主要原料的鱼丸口感及中国淡水养殖行业发展有重要意义。

高黏度聚丙烯酸钠溶液的制备及应用

以丙烯酸为单体,过硫酸钾、亚硫酸氢钠为氧化还原引发剂,制备成聚丙烯酸钠溶液,再加入交联剂和催化剂制成整理液,用整理液浸轧聚丙烯织物,焙烘得到超吸水织物。结果表明,在反应温度70℃、丙烯酸质量分数15%、丙烯酸中和度40%、引发剂质量分数0.6%、反应时间6 h的条件下,所制备的聚丙烯酸钠溶液黏度达到210.156 Pa·s。在聚丙烯酸钠溶液质量浓度800 g/L、中和度75%、甘油质量浓度6.9 g/L、次亚磷酸钠质量浓度40 g/L、120℃预烘3 min、180℃焙烘90 s的条件下,制得的超吸水织物中的树脂吸水倍率为67 g/g。

聚丙烯酸和聚苯乙烯磺酸钠调控制备多孔碳酸钙

多孔碳酸钙微球是一种良好的新型缓释载体,在药物缓释、农药控释、涂层防护、橡胶抗老化等领域有广阔的应用前景,合成具有丰富纳米孔道的碳酸钙微球是实现缓释的关键。以氯化钙和碳酸钠为反应原料,选用聚丙烯酸(PAA)为表面活性剂、聚苯乙烯磺酸钠(PSS)为晶型调控剂,通过复分解法制备出球霰石型多孔碳酸钙微球。采用扫描电子显微镜、透射电子显微镜、红外光谱仪、粒度分析仪、比表面及孔隙度分析仪、热重分析仪等手段对获得产物进行表征分析,并研究PAA、PSS浓度对碳酸钙微球形貌和晶型的影响。结果表明,在反应温度为80℃、搅拌速率为600 r/min、PAA和PSS的质量浓度分别为3.0 g/L和3.6 g/L时,可制备出粒径均一、形貌良好、孔隙率较大的多孔碳酸钙微球。

服用聚苯硫醚纤维的制备及其性能

为提高聚苯硫醚(PPS)纤维的吸湿性能、染色性能和抗紫外线性能,利用双螺杆挤出机和熔融纺丝机将聚丙烯酸钠(PAAS)和纳米TiO_(2)与PPS共混制备复合纤维,并对PPS/PAAS/TiO_(2)复合纤维的结构、性能进行了分析。结果表明:PAAS和纳米TiO_(2)在PPS基体中的分散相容良好,纳米TiO_(2)可提高PPS的结晶度,而PAAS会降低PPS的结晶度;当PAAS质量分数为2%时,复合纤维的综合性能最优,断裂强度为3.06 cN/dtex,断裂伸长率为30.4%,水接触角达52.1°,标准回潮率提高到3.5%,上染率为90.9%,耐皂洗色牢度达到5级,耐光照色牢度达到7级,50℃加速紫外光老化120 h后强度保持率在85%以上。PAAS和纳米TiO_(2)附带的功能基团和在PPS基体中形成的多级网络结构提高了复合纤维吸湿性、染色性能和抗紫外线性能。

Research on various factors influencing the moisture absorption property of sodium polyacrylate

Sodium polyacrylate was synthesized with acrylic acid as the monomer, and sodium bisulfate and ammonium persulfate as the initiator, by means of aqueous solution polymerization. The factors influencing the properties of moisture absorption, such as monomer concentration, dosage of initiator, and reaction temperature were systematically investigated. The experimental results indicate that the moisture-absorbing property of this polymer was better than other traditional material, such as silica gel, and molecular sieve. The best reaction condition and formula are based on the orthogonal experiment design. The optimum moisture absorbency of sodium polyacrylate reaches 1.01 g/g. The mathematical correlation of this polymer with various factors and moisture absorbency is obtained based on the multiple regression analysis. The moisture content intuitive analysis table shows that neutralization degree has the most significant influence on moisture absorbency, followed by monomer concentration and reaction temperature, while other factors have less influence.

Flocculation Mechanism of Synthetic Goethite Suspension Using Hydroxamated Polymer and Sodium Polyacrylate

The flocculation effects of homemade hydroxamated flocculant(HPAA)and commercially available sodium polyacrylate(PAAS)on synthetic goethite suspensions with different solid contents were studied.The adsorption mechanism of HPAA or PAAS on the surfaces of goethite was investigated.The settling rate of 50 g/L goethite suspension with HPAA(1.74 m/h)was faster than that with PAAS(0.54 m/h),which indicated that HPAA exhibits better flocculation performance than PAAS does.It could be found that the stretching vibration of carbonyl band in hydroxamic acid groups of HPAA was downshifted from 1 654 cm^(-1) to 1 645 cm^(-1) and a new adsorption band appeared at 1 455 cm-1,which demonstrated that a five-membered ring chelate may be formed among iron atoms of goethite surfaces,the hydroxyl groups and the carbonyl groups in hydroxamic acid groups of HPAA.In the case of PAAS,the separation of the asymmetric and symmetric stretches of the carboxylate groups in adsorbed PAAS was 163 cm-1,which was greater than that of unadsorbed PAAS with 157 cm^(-1).There was no indication of a contribution from the monodentate adsorption between iron atoms of goethite surfaces and carboxylate groups of PAAS,but there may exist a bi-dentate bridging structure.Compared with synthetic goethite,XPS curve fittings of Fe 2p spectra showed that the binding energies of the main Fe 2p3/2 and Fe 2p1/2 resolved peaks on HPAA-treated goethite surfaces were correspondingly decreased by 0.9 and 0.7 e V,while those on PAAS-treated goethite surfaces were correspondingly decreased by 0.7 and 0.3 e V.The characteristic N 1s peak of HPAA and C 1s peak of PAAS were correspondingly detected on HPAA-treated and PAAS-treated goethites,and a binding energy change of N 1s spectrum of adsorbed HPAA was observed.The relative atomic ratios of C/Fe,N/Fe and O/Fe on HPAA-treated and PAAS-treated goethite surfaces were increased.All the results suggested that HPAA or PAAS was adsorbed on the goethite surfaces by the chemisorption,and a stronger adsorption of HPAA on the goethite surfaces happened than that of PAAS.

以聚丙烯酸钠为保护剂制备单分散纳米金粒子

以聚丙烯酸钠(PAAS)为保护剂,氯金酸溶液为前驱体,采用水合肼还原氯金酸的化学还原法成功地制备了单分散的纳米金粒子。利用X射线衍射(XRD),紫外分光光度计(UV-vis),透射电子显微镜(TEM)、红外光谱仪(FT-IR)和扫描电镜(SEM)等分析测试设备对样品进行了深入的研究与分析。讨论了反应条件对纳米金粒子粒径和形貌的影响。研究表明:所得到的纳米金粒径较小,分布较为均匀;氯金酸溶液用量、PAAS溶液用量和还原剂用量等对纳米金粒子的粒径影响较大。在本研究中,当PAAS溶液(0.1 g/L)用量为5 mL、氯金酸溶液(2 g/L)用量为1 mL、水合肼(85%)用量为4 mL时,所制备纳米金的粒径最小,平均粒径约为50 nm,均匀地分布在20~60 nm之间。