有机改性凹凸棒土复合P (AA-co-AM)高吸水性树脂的制备及性能研究

以过硫酸铵为引发剂,表面丙烯酰基化的凹凸棒土(AT-MPS)为交联剂,采用水溶液聚合法制备了丙烯酰基化凹凸棒土复合聚(丙烯酸-co-丙烯酰胺)高吸水性树脂[AT-MPS/P (AA-co-AM)].考察了中和度、丙烯酸与丙烯酰胺的单体比、引发剂用量以及凹凸棒土用量对复合吸水树脂吸液性能的影响.采用红外光谱(FTIR)、热失重分析(TGA)以及扫描电镜(SEM)等方法对复合吸水树脂进行了表征.结果表明,丙烯酸中和度为75％、m(AA)∶m(AM) =4∶1、引发剂用量为0.8％、AT-MPS用量为8％时,复合吸水树脂的最大吸水倍率为347.7 g/g,最大吸盐水倍率为43.5 g/g.红外光谱分析结果表明,凹凸棒土参与了聚合交联反应;SEM表明,凹凸棒土在复合吸水树脂中具有良好的分散性.     

凹凸棒黏土/黄原胶接枝改性高吸水性树脂的制备

以丙烯酸(AA)、丙烯酰胺(AM)为单体对黄原胶(XG)进行接枝改性,再以N,N′-亚甲基双丙烯酰胺(NMBA)为交联剂,过硫酸铵(APS)为引发剂,加入凹凸棒黏土,采用溶液聚合法合成了一种新型复合高吸水性树脂。通过单因素试验研究了AA中和度、交联剂用量、引发剂用量、反应温度和凹凸棒黏土用量等因素对该树脂吸水(吸盐水)性能的影响,利用傅里叶红外光谱(FT-IR)仪、热重分析(TGA)仪对其结构和热性能进行了表征。结果表明:制备高吸水性树脂的最佳工艺条件为AA中和度70%,反应温度70℃,w(交联剂)=0.06%,w(APS)=1.0%,w(凹凸棒黏土)=5%;在最佳工艺条件下制备的高吸水性树脂,其最大吸水倍率、吸盐水倍率分别为827、109 g/g。     

微波辐射下耐盐性高吸水树脂的制备

对微波辐射下丙烯酸(AA)、丙烯酰胺(AM)和凹凸棒的水溶液聚合反应进行研究,合成凹凸棒复合P(AAAM)高吸水树脂,探讨微波功率、辐射时间、单体配比、中和度、引发剂用量、交联剂用量等对高吸水性树脂吸液倍率的影响,并用红外光谱对产物的结构进行表征.合成的高吸水树脂吸水倍率迭1 580 g/g,在质量分数为0.9%的食盐水中的吸液倍率达170 g/g.     

P(AA/AM)-g-凹凸棒土吸水树脂性能的研究

以过硫酸钾、亚硫酸钠氧化还原体系为引发剂,偶氮二异丁腈(AIBN)为二次引发剂,N,N'-亚甲基双丙烯酰胺为交联剂,通过水溶液聚合法制备了(丙烯酸/丙烯酰胺)-g-凹凸棒土吸水树脂[P(AA/AM)-g-AT]。通过傅里叶变换红外光谱分析证明了大分子链成功地接在了凹凸棒土上;所制得的吸水树脂吸水倍率达125 g/g,吸盐倍率(0.9 %的NaCl溶液)达23 g/g;扫描电子显微镜观察发现凹凸棒土在树脂中具有较好的分散性,也获得了很好的相容性;热失重分析表明P(AA/AM)-g-AT树脂的热稳定性要高于纯有机树脂;凹凸棒土的存在和二次引发剂AIBN的加入能够分别降低材料中的单体残余量。     

反相悬浮聚合法制备耐高温吸水材料及其性能研究

针对现有吸水材料存在耐高温性能差的问题,以丙烯酸钠为聚合单体,环己烷为连续相,Span80为分散剂,四烯丙基氯化铵为交联剂,过硫酸铵为引发剂,采用反相悬浮聚合法制备了耐高温吸水材料。探讨了交联剂浓度、分散剂用量和引发剂浓度等对吸水材料在不同温度条件下吸水性能的影响,并对吸水材料结构进行分析。最佳的聚合条件:分散剂、交联剂、引发剂占单体的质量分数分别为5.00%,0.14%,0.10%,在此条件下制备的吸水材料在200℃的蒸馏水中的吸水倍率为400 g/g,耐高温性能良好。     

高吸水性树脂的研制

通过正交实验方法,以N,N′-亚甲基双丙烯酰胺(MBA)作交联剂,过硫酸铵作引发剂,将部分中和的丙烯酸和丙烯酰胺聚合制备高吸水性树脂,考察了引发剂用量、交联剂用量、丙烯酰胺用量和中和度对树脂吸水性能的影响,所得高吸水性树脂吸水可达1297g/g,吸0.9%的盐水90g/g。     

壳聚糖-硅藻土-聚丙烯酸高吸水性树脂

以丙烯酸,硅藻土为原料,过硫酸铵为引发剂,N,N’-亚甲基双丙烯酰胺为交联剂,通过接枝壳聚糖制备了壳聚糖-硅藻土-聚丙烯酸高吸水性树脂,并对高吸水性树脂的结构进行了红外光谱的表征,系统研究了引发剂、交联剂、硅藻土的用量,丙烯酸与壳聚糖的质量比,丙烯酸的中和度,反应温度以及反应时间对高吸水性树脂吸水率的影响。实验结果表明,丙烯酸与壳聚糖的质量比为12∶1,硅藻土的含量为1%,引发剂和交联剂的用量分别为2.5%和0.16%,中和度为70%,反应温度为60℃,反应时间为5.5h时,合成的壳聚糖-硅藻土-聚丙烯酸高吸水性树脂吸水(盐)率最高,分别为145g/g和30g/g。     

凹凸棒基高分子固沙材料的表征及性能研究

以酸化凹凸棒石和丙烯酰胺为原料,N-N亚甲基丙烯酰胺为交联剂,过硫酸钾为引发剂,采用水溶液聚合法合成了凹凸棒石基高分子固沙材料.通过研究不同浓度硫酸活化的凹凸棒石基高分子固沙材料的吸水性能、保水性能、pH值以及X衍射以及扫描电镜,结果表明4 mol/L硫酸改性的凹凸棒石基高分子固沙材料具有更好的吸水性能和保水性能;pH值的变化对4 mol/L硫酸改性的凹凸棒石基高分子固沙材料具有较大的影响;X衍射以及扫描电镜表明3 mol/L和4 mol/L硫酸改性的凹凸棒石基高分子固沙材料具有更好的吸附性能.研究结果对于加强深入硫酸改性的凹凸棒石基高分子固沙材料的研究重具有要意义,以期制备出一种新型环保型复合高吸水性凹凸棒石基高分子固沙材料.     

用丙烯酸-高岭土制备高吸水性树脂及结构表征

用丙烯酸-高岭土采用静态水溶液法制备复合吸水性树脂(简称复合树脂),考察了高岭土含量、聚合温度、丙烯酸单体的含量、丙烯酸中和度、引发剂和交联剂的用量对复合树脂吸水量的影响。实验结果表明,复合树脂的最佳制备条件为:聚合温度为70℃,丙烯酸单体的质量分数为35%,丙烯酸中和度为70%,引发剂占单体的质量分数为0.2%,交联剂占单体的质量分数为0.02%,高岭土占单体的质量分数为12%;在此条件下制备的复合树脂对蒸馏水的吸水量为920g/g,傅里叶变换红外光谱和扫描电镜表征结果表明,复合树脂是一种典型的海/岛结构,丙烯酸和高岭土之间存在共聚反应。     

纸浆纤维素基高吸水材料的制备及性能研究

以纸浆纤维素为骨架接枝单体丙烯酸和丙烯酰胺,在无N2保护下利用微波辅助引发,考察了纸浆纤维/丙烯酸/丙烯酰胺质量比、单体浓度、引发剂用量和交联剂用量对材料吸水性能的影响,通过FTIR、XRD对所得吸水材料进行了结构表征。所得吸水材料为白色透明薄膜状,易于加工成型,吸水后柔软度及强度很高,纸浆质量分数为25%时吸去离子水倍率为471g/g,吸0.9%NaCl水溶液倍率为135g/g,吸雨水倍率为89g/g,并可反复使用,具有一定的应用价值。     

Studies on poly(acrylic acid)/attapulgite superabsorbent composite. I. Synthesis and characterization

A novel poly(acrylic acid)/attapulgite superabsorbent composite was synthesized by graft copolymerization reaction of acrylic acid (AA) on attapulgite micropowder using N,N′‐methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) as an initiator in aqueous solution. The effects on water absorbency of such factors as reaction temperature, initial monomer concentration, degree of neutralization of AA, amount of crosslinker, initiator, and attapulgite were investigated. These crosslinked superabsorbent composites were characterized by thermogravimetetric analysis and scanning electron microscopy. The graft copolymerization reaction of AA on attapulgite micropowder was characterized by FTIR. The water absorbencies for these superabsorbent composites in water and saline solutions were investigated and water‐retention tests were carried out. Results obtained from this study show that the water absorbency of the superabsorbent composite synthesized under optimal synthesis conditions with an attapulgite content of 10% exhibited an absorption of 1017 g H₂O/g sample and 77 g H₂O/g sample in distilled water and in 0.9 wt % NaCl solution, respectively. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1596–1603, 2004     

Preparation of starch‐graft‐poly(acrylamide)/attapulgite superabsorbent composite

A novel starch‐graft‐poly(acrylamide)/attapulgite superabsorbent composite was synthesized by graft copolymerization reaction of starch, acrylamide (AM), and attapulgite micropowder using N.N‐methylene‐bisacrylamide (MBA) as a crosslinker and ammonium persulphate (APS) as an initiator in aqueous solution, followed by hydrolysis with sodium hydroxide. The effects on water absorbency, such as amount of crosslinker, initiator, attapulgite, weight ratio of acrylamide to starch in the feed, gelatinization conditions of starch and molar ratio of NaOH to acrylamide, and so forth, were investigated. These superabsorbent composites were characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The water absorbencies for these superabsorbent composites in water and saline solution were investigated, and water retention tests were carried out. Results obtained from this study showed that the water absorbency of superabsorbent composite synthesized under optimal synthesis conditions with an attapulgite content of 10% exhibit absorption of 1317 g H₂O/g sample and 68 g H₂O/g sample in distilled water and in 0.9 wt % NaCl solution, respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1351–1357, 2005     

凹凸棒黏土纯度对复合高吸水性树脂吸水性能的影响

将凹凸棒黏土分级处理后,以不同纯度的凹凸棒黏土为无机组分,过硫酸铵为引发剂,N,N'-亚甲基双丙烯酰胺为交联剂,制备了羧甲基纤维素接枝丙烯酸/凹凸棒黏土复合高吸水性树脂,考察了复合高吸水性树脂的吸水倍率、吸水速率和在不同pH介质中的溶胀性能。红外光谱表明,丙烯酸已接枝到羧甲基纤维素的骨架上,凹凸棒黏土参与了聚合反应。扫描电镜观察表明,凹凸棒黏土在高吸水性树脂中有良好的分散性能,改善了基体表面的多孔结构。研究表明,在相同添加量下,凹凸棒黏土中含有更多的Ca2+和Mg2+离子,有助于改善复合高吸水性树脂的综合性能。     

Synthesis,characterization and swelling behaviors of hydroxyethyl cellulose‐g‐poly(acrylic acid)/attapulgite superabsorbent composite

In this work, a series of novel hydroxyethyl cellulose‐ g‐poly(acrylic acid)/attapulgite (HEC‐g‐PAA/APT) superabsorbent composites were prepared through the graft polymerization of hydroxyethyl cellulose (HEC), partially neutralized acrylic acid (AA), and attapulgite (APT) in aqueous solution, and the composites were characterized by means of Fourier‐transform spectroscopy, scanning electron microscopy, and transmission electronmicroscopy. The effects of polymerization variables including concentrations of the initiator and crosslinker and APT content on water absorbency were studied, and the swelling properties in various pH solutions as well as the swelling kinetics in various saline solutions were also systematically evaluated. Results showed that the introduction of 5 wt% APT into HEC‐g‐PAA polymeric network could improve both water absorbency and water absorption rate of the superabsorbent composites. In addition, the superabsorbent composites retained high water absorbency over a wide pH range of 4–10, and the swelling kinetics of the superabsorbent composites in CaCl₂ and FeCl₃ solutions exhibited a remarkable overshooting phenomenon. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

Study on superabsorbent composite. XI. Effect of thermal treatment and acid activation of attapulgite on water absorbency of poly(acrylic acid)/attapulgite superabsorbent composite

The effect of acid activation and thermal treatment of attapulgite on water absorbency of superabsorbent composite were investigated. Under the same preparation conditions, superabsorbent composite prepared with natural attapulgite exhibited a water absorbency of 639 g/g and it merely kept 71% of its initial water absorbency after 5 times of swelling–deswelling–reswelling test. However, superabsorbent composites prepared with 2–10 M hydrochloric acid acidified attapulgite and 100–400°C thermal treated attapulgite respectively exhibited the water absorbency of 884–1,241 g/g and 701–1,515 g/g. Also, those superabsorbent composites can keep 87% and 85% of their initial water absorbency after 5 times of swelling–deswelling–reswelling test, respectively. These results showed that, compared with superabsorbent composite prepared with natural attapulgite, the comprehensive water‐absorbing properties of poly(acrylic acid)/ attapulgite superabsorbent composites were improved effectively by acid activation and thermal treatment of attapulgite. This improvement of water absorbencies and gel strength of superabsorbent composite may be due to synthetical factors such as changes in the crystalline structure and the specific surface area and improvement of the number and the activity of hydroxyl groups of attapulgite, which in turn influence the grafting efficiency of monomer, crosslinking density, and the structure of superabsorbent composite network. POLYM. COMPOS., 28:397–404, 2007. © 2007 Society of Plastics Engineers     

Study on superabsorbent composite. XV. Effects of ion‐exchanged attapulgite on water absorbency of superabsorbent composites

A series of superabsorbent composite, polyacrylamide/attapulgite, from acrylamide (AM) and ion‐exchanged attapulgite (APT) was prepared by aqueous polymerization, using N,N′‐methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) as an initiator. The effects of ion‐exchanged APT on water absorbency of superabsorbent composites in distilled water and in 0.9 wt% NaCl solution were studied. The result indicates that higher cation‐exchange capacity (CEC) and lower specific surface area (SSA) of APT treated with various anions are of benefit for improving water absorbency in distilled water. The effects of AlCl₃ solution concentration and Al³⁺‐exchanged APT content on water absorbency of the composite were also investigated. The concentration of AlCl₃ solution has a great influence on water absorbency of the superabsorbent composite. Al³⁺‐exchange of APT could also enhance reswelling ability of the corresponding composite, which indicates that Al³⁺‐exchange of APT could improve gel strength and gives a direct evidence for its acting as an inorganic assistant crosslinker in the polymeric network. POLYM. COMPOS., 28:208–213, 2007. © 2007 Society of Plastics Engineers     

丙烯酰胺/甲基丙烯酸丁酯改性纤维素的研究

以纤维素为基体,丙烯酰胺(AM)、甲基丙烯酸丁酯(BMA)为接枝单体,过硫酸钾为引发剂,N,N'-亚甲基双丙烯酰胺为交联剂,聚乙烯吡咯烷酮为分散剂,通过悬浮接枝聚合法制备出了纤维素基吸水吸油材料;考察了单体用量、引发剂用量、反应时间、反应温度及交联剂用量等因素对接枝聚合物的吸水、吸油性能的影响。结果表明:在单体与纤维素的质量比为3.0∶1.0,AM∶BMA的质量比为2.0∶1.0,相对于单体,引发剂质量分数为6.0%,交联剂质量分数为0.5%,分散剂质量分数为0.5%,反应温度为70℃,反应时间为4 h的条件下,得到纤维素-AM-BMA接枝共聚物,其吸油倍率为11.55 g/g,吸水倍率为23.51 g/g,聚合度为534.6。     

耐盐型丙烯酸-丙烯酰胺接枝共聚高吸水树脂的合成及其性能研究

采用溶液聚合法,以丙烯酸(AA)和丙烯酰胺(AM)为单体,N,N＇-亚甲基双丙烯酰胺(NMBA)为交联剂,过硫酸钾(KPS)为引发剂.合成出丙烯酸-丙烯酰胺接枝共聚高吸水树脂.探讨了单体比[m(丙烯酸):m(丙烯酰胺)]、交联剂和引发荆用量、单体中和度及聚合温度对树脂吸水率的影响.IR光谱表明,丙烯酸和丙烯酰胺发生了接...     

Synthesis and characterization of a salt‐resisting superabsorbent based on poly(acrylic acid) with sodium tungstate as a crosslinker

A novel salt‐resistant superabsorbent polymer was synthesized by solution polymerization from the monomer acrylic acid (AA) with potassium persulfate as the initiator. Sodium tungstate was first employed as a crosslinker in the preparation to achieve a better crosslinked polymer (WPAA). In addition to the xerogel WPAA, sodium hydroxide and tris(2‐hydroxyethyl)amine (TEA) were introduced for the preparation of WPAA–sodium and WPAA–TEA hydrogels, respectively. The effect on the water absorbency of factors such as the reaction temperature, degree of neutralization of AA, and amounts of the crosslinker sodium tungstate and the initiator were investigated. The crosslinked xerogels were characterized with infrared spectroscopy. These crosslinked superabsorbent composites with sodium tungstate were characterized with thermogravimetric analysis and scanning electron microscopy. The water absorbencies of these superabsorbent composites in water and saline solutions were investigated. Results obtained from this study showed that under the same synthesis conditions, in comparison with superabsorbent composites with an aluminum salt as a crosslinker and styrene as a graft copolymer, the salt resistance of the superabsorbent composite synthesized with sodium tungstate as a crosslinker was obviously enhanced. Moreover, the WPAA–TEA xerogel had absorbency values of 223.6 and 81.9 g/g for distilled water and a 0.9 wt % NaCl solution, respectively, and it showed better salt resistance and a better water‐absorbing rate than the WPAA–sodium xerogel because of the modification with triethanolamine. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Study on superabsorbent composite. VIII. Effects of acid‐ and heat‐activated attapulgite on water absorbency of polyacrylamide/attapulgite

A novel superabsorbent composite, polyacrylamide/attapulgite, from acrylamide (AM) and attapulgite (APT), was prepared by free‐radical polymerization, using N,N′‐methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) as an initiator. The effects of hydrochloric acid (HCl) concentration, acidification time, and acidification temperature while acidifying APT and temperature and APT heat‐activation on water absorbency of the superabsorbent composite in distilled water and in 0.9 wt % NaCl solution were studied. The water absorbency first decreases with increasing the HCl concentration while acidifying APT, and then increases with further increasing the HCl concentration. Prolongation of acidification time is of benefit to the increase of water absorbency. At a given HCl concentration, water absorbency for the composite increases with increasing acidification temperature. An important increase in water absorbency was observed after incorporating heat‐activated APT into the polymeric network, reaching a maximum of 1964 g g^?1 with the APT heat‐activated at 400°C. Acid‐ and heat‐activation can influence chemical composition, crystalline structure, cation exchange capacity (CEC), and specific surface area of APT according XRF, XRD, FTIR analysis, and physicochemical properties test, and then on water absorbency of corresponding PAM/APT superabsorbent composite. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2419–2424, 2007