首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
高吸水性树脂是一种新型功能高分子材料,由于其优越的吸水保水性能,已在农林园艺和生理卫生用品等领域得到了应用,但它仍然存在抗盐性能差、吸水后凝胶强度低等不足.近年来,有机.无机复合高吸水性树脂因具有较高的吸水性能和低廉的生产成本而受到了广泛的关注,使用的无机粘土主要有高岭土、蒙脱土和凹凸棒土等.粘土具有活性基团和键合点,加入到高吸水性树脂三维网络中可以改善树脂的网络结构,提高其综合性能.凹凸棒土是一种含水富镁铝的层链状硅酸盐,相对于其它粘土,它具有很好的抗盐、吸附和胶体性能。  相似文献   

2.
高吸水性树脂凭借其优越的吸水和保水性能,已成为国民经济各个领域中不可或缺的重要材料,但传统的高吸水性树脂吸水速度慢、耐盐性差、凝胶强度低等问题限制了其发展。针对高吸水性树脂日益明显的缺陷,科研人员开始着手研究合成和加工新方法,以降低树脂生产成本低,提高树脂生物降解性、凝胶强度、吸水性和耐盐性等性能,从而推广产品使用范围。本文基于近年来该领域的研究,概括了高吸水性树脂目前主要存在的性能缺陷,并提出相应的改性策略来提高吸水性树脂的综合性能。  相似文献   

3.
高吸水性树脂   总被引:11,自引:0,他引:11  
高吸水性树脂,可以吸收其本身重量的几百倍水。将水溶性高分子如羧甲基纤维素、聚丙烯酸钠盐或聚乙烯醇进行轻微的交联可以得到。由于其高吸水性、在压力下的高保水性和高增稠性,被广泛应用于纸尿布、生理巾、土壤保水剂、工业脱水剂、增稠剂等。  相似文献   

4.
高吸水性树脂的合成和应用   总被引:14,自引:0,他引:14  
本文综述了近年来高吸水性树脂的研究进展,主要包括3个方面:(1)高吸水性树脂的制备;(2)高吸水性树脂的结构及性能表征;(3)高吸水性树脂的应用开发。  相似文献   

5.
研究了部分水解聚(丙烯酸甲酯-乙酸乙烯酯-甲基丙烯酸甲酯)高吸水性树脂-HP(MA-VAc-MMA)的合成,讨论了聚合,水解工艺条件对该树脂吸水(液)性能的影响,用红外,X-射线衍射和电子衍射等方法测定了共聚物的结构。结果表明,HP(MA-VAc-MMA)树脂的吸水能力为:去离子水837ml/g、自来水440ml/g、0.9%NaCl溶液ml/g、合成血119ml/g、合成尿73ml/g;该树脂具有结晶结构,与PVC树脂共混可制备吸水膨胀性材料。  相似文献   

6.
有机凹凸棒粘土的制备及复合高吸水性树脂的性能   总被引:2,自引:0,他引:2  
有机凹凸棒粘土的制备及复合高吸水性树脂的性能;凹凸棒粘土;有机改性;高吸水性树脂  相似文献   

7.
高吸水性树脂   总被引:5,自引:0,他引:5  
陈明亮 《广州化学》2004,29(2):57-61
综述了国内高吸水性树脂的研究进展,其中包括高吸水性树脂的制备方法、类型、影响其吸水性能的因素以及功能与应用。  相似文献   

8.
腐植酸(HA)是土壤腐殖质的主要成分,含有多种功能基团。随着HA基础和应用研究的不断深入,将具有反应活性和生物活性的HA引入到高吸水性树脂中,既能发挥HA改良土壤、增效化肥、刺激生长、增强抗逆和改善品质的功效,又可改善高吸水性树脂的吸水和耐盐性能,同时大幅度降低高吸水性树脂的制备成本。本文综述了近年来HA高吸水性树脂的...  相似文献   

9.
高吸水性树脂研究进展   总被引:31,自引:2,他引:29  
介绍了高吸水性树脂的结构、性能及其表征,结合经典理论与最新研究从热力学和动力学角度阐述其吸水机理,着重分析合成条件,组份和方法对高吸水性树脂性能的影响机制,简略地介绍了高吸水性树脂三十年来的发展及广阔的应用领域,并预测其研究与开发前景  相似文献   

10.
高吸水性枝脂研究进展   总被引:28,自引:0,他引:28  
介绍了高吸水性树脂的结构,性能及其表征,结合经典理论与最新研究从热力学和动力学角度阐述其吸水机理,着重分析合成条件,组份和方法对高吸水性树脂性能的影响机制,简略地介绍了高吸水性树脂三十年来的发展及广阔的应用领域,并预测其研究与开发前景。  相似文献   

11.
Temperature-sensitive hydrogels based on N-t-butylacrylamide (TBA), acrylamide (AAm), and sodium alginate were prepared by free radical polymerization method. Methylenebisacrylamide (MBA) and amonium persulfate (APS) were applied as water soluble crosslinker and initiator, respectively. The chemical structure of the hydrogels was confirmed by FT-IR spectroscopy and thermogravimetric analysis (TGA) methods. Morphology of the samples was examined by scanning electron microscopy (SEM). By changing the initial TBA/AAm mole ratios, hydrogels with different swelling properties were obtained. The rate parameters were found to be 2.0, 2.4, and 3.5 min for the superabsorbents with AAm/TBA weight ratio of 1.0, 1.3 and 2.0 respectively. The swelling behavior in distilled water and different pH solutions was investigated. A preliminary swelling kinetics and the absorbency under load (AUL) were also studied. At the applied pressure (2.07 kPa), maximum swelling was found to be 17, 19, and 21 (g/g) for the superabsorbent hydrogels with AAm/TBA weight ratios of 1.0, 1.5 and 2.0, respectively.  相似文献   

12.
Hydrogels are attractive biomaterials for three-dimensional cell culture and tissue engineering applications. The preparation of hydrogels using alginate and gelatin provides cross-linked hydrophilic polymers that can swell but do not dissolve in water. In this work, we first reinforced pure alginate by using polyoxyethylene as a supporting material. In an alginate/PEO sample that contains 20 % polyoxyethylene, we obtained a stable hydrogel for cell culture experiments. We also prepared a stable alginate/gelatin hydrogel by cross-linking a periodate-oxidized alginate with another functional component such as gelatin. The hydrogels were found to have a high fluid uptake. In this work, preparation, characterization, swelling, and surface properties of these scaffold materials were described. Lyophilized scaffolds obtained from hydrogels were used for cell viability experiments, and the results were presented in detail.  相似文献   

13.
Sodium alginate-g-poly(acrylic acid-co-2-hydroxyethyl methacrylate)/montmorillonite superabsorbent composites (SACs) were prepared by graft copolymerization of acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) onto sodium alginate (Na-Alg) in the presence of montmorillonite (MMT) using N,N′-methylenebisacrylamide (MBA) as a crosslinker and potassium persulfate (KPS) as an initiator in aqueous solution. The composite structures were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Thermal Gravimetric Analysis (TGA) and Scanning Electron Microscope (SEM). The effect of % initiator, crosslinker amount and clay ratio on the swelling capacity was investigated. The results indicated that the highest swelling capacity of the composites in distilled water was 752 g/g by using 1.25% KPS and 0.06% MBA, 75% AA, 6.25% HEMA and 12.5% Na-Alg. Different samples were loaded with urea to evaluate their release potentials, and the release was studied by measuring the conductivity. The amount of urea release increased with increasing MMT amount.  相似文献   

14.
A series of polyurethane-alginate (APU/AG) compositions with pH/temperature-responsive character and regulated viscosity were obtained by adding different quantities of sodium alginate into an aqueous polyurethane anionic dispersion. Rheological, thermoresponsive, mechanical properties and swelling behavior dependencies on composition have been determined. APU/AG compositions reached equilibrium swelling and deswelling states within about 60 min. They display non-Newtonian flow and posses thixotropic properties. The strength of the films increases after their treatment with CaCl2 at the expense of cross-linking of alginate with divalent calcium ions and of forming an alginate network.  相似文献   

15.
In this study, (sodium alginate (NaAlg)/acrylamide (AAm)) interpenetrating polymer networks (IPN) have been prepared at three different compositions, where the sodium alginate composition varies 1, 2, and 3% (w/v) in 50% (w/v) acrylamide solutions. These solutions have been irradiated with a 60Co‐γ source at different doses. The percent conversion was determined gravimetrically and 100% gelation was achieved at the 10.0 kGy dose. The swelling results at pH 7.0 and 9.0 indicated that (NaAlg/AAm)3IPN hydrogel, containing 3% NaAlg showed maximum % swelling in water, with swelling increasing in the order of Ni2+>Cd2+>Pb2+. Diffusion in aqueous solutions of metal ions within (NaAlg/AAm)IPN hydrogels was found to be Fickian character. Diffusion coefficients of (NaAlg/AAm)IPN hydrogels in water and aqueous solutions of metal ions were calculated. The maximum weight loss temperature and half life temperature for NaAlg, PAAm, (NaAlg/AAm)IPN and (NaAlg/AAm)IPN‐metal ion systems were found from thermal analysis studies. In the adsorption experiments, the efficiency of (NaAlg/AAm)IPN hydrogels to adsorb nickel, cadmium and lead ions from water was studied. (NaAlg/AAm)IPN hydrogels showed different adsorption for different aqueous solution of metal ion at pH 7.0. Adsorption isotherms were constructed for the (NaAlg/AAm)IPN‐metal ion systems. S type adsorption in the Giles classification system was found.  相似文献   

16.
将线性聚(N-异丙基丙烯酰胺)(PNIPAAm)和海藻酸钠(SA)分子同时引入到PNIPAAm凝胶中,制备了交联聚(N-异丙基丙烯酰胺)/(海藻酸钠/聚(N-异丙基丙烯酰胺))半互穿网络(Cr-PNIPAAm/(SA/PNIPAAm)semi-IPN)水凝胶。在弱碱性条件下(pH=7.4),改变SA与线性PNIPAAm的质量比对Cr-PNIPAAm/(SA/PNIPAAm)semi-IPN水凝胶的溶胀度没有太大的影响。在酸性条件下(pH=1.0),其溶胀度随着SA与线性PNIPAAm质量比的减小而增大。由于亲水性SA与线性PNIPAAm的协同作用,Cr-PNIPAAm/(SA/PNIPAAm)semi-IPN水凝胶的消溶胀速率得到很大提高。  相似文献   

17.
In this study, a reduced graphene oxide (rGO)@sodium lignosulfonate (NaLS) composite material was fabtricated using a one-step method and then mixed with natural polysaccharide calcium alginate (CaAlg) to prepare the rGO@NaLS/CaAlg pervaporation membrane. The appearance and physical properties of the rGO@NaLS/CaAlg membrane were characterized by scanning electron microscopy and water contact angle. The swelling performance of the membrane and its dehydration performance to organic solvents were evaluated. The results indicate that the addition of rGO@NaLS can increase the hydrophilicity of the rGO@NaLS/CaAlg membrane and reduce its degree of swelling in the ethanol solution. The membrane incorporated with 6 wt% rGO@NaLS exhibits the best pervaporation performance, and ethanol can be purified to 99.8%.  相似文献   

18.
Sodium alginate (Alg) hydrogel films were crosslinked with either calcium poly(γ‐glutamate) (Ca‐PGA) or CaCl2. The hydrophilicity of the resulting hydrogel films was evaluated through swelling tests, water retention capacity tests, and water vapor permeation tests. The swelling ratio, water retention capacity, and the water vapor transmission rate (WVTR) of Alg/Ca‐PGA were higher than those of Ca‐Alg. The swelling ratio of Alg/Ca‐PGA was 651 and 190% at pH 7.4 and pH 1.2, respectively. The tensile strength of Alg/Ca‐PGA hydrogel was lower than that of Ca‐Alg. The results of hemocompatibility test showed that Alg/Ca‐PGA caused shorter activated partial thromboplastin time (APTT) than Ca‐Alg. Both Ca‐Alg and Alg/Ca‐PGA exhibited almost no adsorption of human serum albumin (HSA), whereas the adsorption of human plasma fibrinogen (HPF) of Ca‐Alg was 10 times of that of Alg/Ca‐PGA. In addition, Alg/Ca‐PGA exhibited platelet adhesion higher than Ca‐Alg. Furthermore, both Alg/Ca‐PGA and Ca‐Alg exhibited no cytotoxicity. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

19.
Radiation-induced grafting of acrylic acid onto alginate/chitosan beads was performed in solution at a dose rate of 20.6 Gy/min of Co-60 gamma rays. The effect of absorbed dose on grafting yield was investigated. The characterization of the grafted and un-grafted beads was performed by FTIR spectroscopy and the swelling measurements at different pHs was studied. It is found that as the pH value increases the swelling degree increases up to pH 6 but with further increase in pH value the swelling decreases. Also, it is noticed that the grafting yield increased with increase the irradiation dose. Both un-grafted and grafted alginate/chitosan beads were examined as sorbents for the removal of Pb ions from aqueous solutions. The sorption behavior of the sorbents was examined through pH, and equilibrium measurements. Grafted alginate/chitosan beads presented higher sorption capacity for Pb ions than un-grafted beads.  相似文献   

20.
Different viscosity grade sodium alginate (NaAlg) membranes and modified sodium alginate membranes prepared by solution casting method and crosslinked with glutaraldehyde in methanol:water (75:25) mixture were used in pervaporation (PV) separation of water+acetic acid (HAc) and water+isopropanol mixtures at 30 °C for feed mixtures containing 10–50 mass% of water. Equilibrium swelling experiments were performed at 30 °C in order to study the stability of membrane in the fluid environment. Membranes prepared from low viscosity grade sodium alginate showed the highest separation selectivity of 15.7 for 10 mass% of water in the feed mixture, whereas membranes prepared with high viscosity grade sodium alginate exhibited a selectivity of 14.4 with a slightly higher flux than that observed for the low viscosity grade sodium alginate membrane. In an effort to increase the PV performance, low viscosity grade sodium alginate was modified by adding 10 mass% of polyethylene glycol (PEG) with varying amounts of poly(vinyl alcohol) (PVA) from 5 to 20 mass%. The modified membranes containing 10 mass% PEG and 5 mass% PVA showed an increase in selectivity up to 40.3 with almost no change in flux. By increasing the amount of PVA from 10 to 20 mass% and keeping 10 mass% of PEG, separation selectivity decreased systematically, but flux increased with increasing PVA content. The modified sodium alginate membrane with 5% PVA was further studied for the PV separation of water+isopropanol mixture for which highest selectivity of 3591 was observed. Temperature effect on pervaporation separation was studied for all the membranes; with increasing temperature, flux increased while selectivity decreased. Calculated Arrhenius parameters for permeation and diffusion processes varied depending upon the nature of the membrane.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号