丙烯酸盐与丙烯酰胺共聚制备耐盐性高吸水树脂

以N,N-亚甲基双丙烯酰胺为交联剂,过硫酸铵-亚硫酸钠为引发剂,采用水溶液聚合法合成了耐盐性高吸水树脂-聚(丙烯酸钠-co-丙烯酰胺).研究了单体配比、丙烯酸中和度、引发剂及交联剂用量以及反应温度对常压及加压(1.96×103Pa)下吸盐水(wNaCl=0.009)率的影响.并对其结构进行了表征.该耐盐性高吸水树脂常压和加压下吸盐水率分别为50g·g-1和18 g·g-1,且凝胶强度好.     

酯类交联剂交联丙烯酸钠吸水树脂的紫外引发制备与性能

以部分中和的丙烯酸为原料,分别以乙二醇二甲基丙烯酸（EGDMA）、二甲基丙烯酸甘油酯（GDA）与三乙二醇二甲基丙烯酸（TEGDMA）为交联剂,通过紫外引发合成了聚丙烯酸钠缩乙二醇二甲基丙烯酸（PAANa-E）、聚丙烯酸钠缩二甲基丙烯酸甘油酯（PAANa-GDA）、聚丙烯酸钠缩三乙二醇二甲基丙烯酸（PAANa-TE）3种丙烯酸钠高吸水树脂。考察了交联剂用量、单体体积分数、丙烯酸中和度、辐照时间对树脂吸液率的影响,研究了3种不同链长的酯类交联剂制备的树脂吸液率与温度、pH、盐溶液浓度的关系。采用红外、热失重分析对树脂进行了表征。结果表明：以上3种树脂在最佳条件下吸去离子水率和吸NaCl溶液率分别为2 509,170g/g;2 291,125g/g;3 930,219g/g。其中PAANa-TE的吸液率最高,PAANa-E的吸液率次之,PAANa-GDA的吸液率最低。当极性基团类型相同,数量不同时,PAANa-E、PAANa-TE树脂的吸液率随着交联剂所含醚基数目的增加显著提高。     

耐水解高吸水树脂的合成与性能研究

采用2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、丙烯酸(AA)、十二烷基苯磺酸钠(LAS)为主要原料,以二乙烯基苯(DVB)为交联剂制备出P(AMPS+AA)高吸水膨胀树脂,考察了AMPS与AA配比、中和度、交联剂种类与用量、LAS加量等合成工艺对吸水树脂性能的影响。研究结果表明,在丙烯酸系吸水树脂中引入AMPS结构单元,有利于提高树脂在盐水中的吸液能力,改善高吸水树脂的耐盐性;在以DVB为交联剂制备P(AMPS+AA)树脂时,LAS加量对树脂性能影响显著,当DVB用量为0.3%-0.45%、十二烷基苯磺酸钠用量0.15%-0.3%时,制备的P(AMPS+AA)树脂具有较高吸水能力,并且其稳定性比N,N’-亚甲基双丙烯酰胺(NMBA)交联的树脂优良,在高温碱性或酸性条件下显示出良好的耐水解性能。     

速溶型高吸水性树脂的制备及性能研究

以丙烯酸为单体，Ｋ＿２Ｓ＿２Ｏ＿８为引发剂，Ｎ，Ｎ’－亚甲基双内烯酰胺为交联剂，进行反相乳液聚合，制得内交联高吸水性树脂。研究了聚合物吸水性能与内烯酸浓度，丙烯酸中和度，引发剂用量，交联剂用过的关系。考察了该树脂的吸水速率，保水性，在不同电解质溶液中的吸水速度及水饱和树脂在盐水中的失水率。     

丙烯酸与丙烯酰胺共聚制备高吸水性树脂

采用溶液聚合法,以N,N’-亚甲基双丙烯酰胺（NMBA）为交联剂,过硫酸钾（KPS）为引发剂合成了高吸水性树脂聚（丙烯酸-丙烯酰胺）（P（AA—AM））,研究了单体配比、丙烯酸中和度、引发剂及交联剂用量、反应温度对树脂在去离子水和0．9％盐水中吸水率的影响．最佳条件下制备的树脂在去离子水中吸水率为750g·g^-1,在0．9％盐水中吸水率为85g·g^-1．     

互穿网络高吸水树脂IPN的合成

采用溶液聚合制备了聚乙烯醇(PVA)和部分中和的丙烯酸-丙烯酰胺共聚物复合的互穿网络高吸水树脂(IPN)。通过正交实验研究了单体浓度,交联剂用量对IPN吸水率的影响。PVA的加入能有效提高IPN的吸水能力。在较适宜的反应条件下,IPN吸蒸馏水量达1481倍,吸0.9%NaCl溶液为130倍。     

水葫芦基保水剂的制备

利用水葫芦中的纤维素,以过硫酸钾为引发剂,N,N-亚甲基双丙烯酰胺为交联剂,采用复合引发剂体系制备出土壤改良用途的水葫芦基保水剂。考察了单体用量、引发剂用量和交联剂用量对保水剂的吸水吸盐性能的影响。结果表明,以水葫芦为原料,与单体AA进行接枝共聚制备水葫芦基保水剂的最优单体与纤维素的质量比为12∶1,最优引发剂KPS用量为单体质量的0.6%,最优交联剂NMBA用量为单体质量的0.12%,制得的树脂吸水吸盐性能最优。     

碳纳米管复合聚丙烯酸钠的制备及吸水性能

以过硫酸铵(APS)为引发剂,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,采用水溶液聚合法制备了碳纳米管/聚丙烯酸钠高吸水树脂。系统考察了碳纳米管质量分数、引发剂、交联剂和聚合温度对树脂吸水性能的影响。结果表明,以单体丙烯酸质量为基准,当交联剂,引发剂和碳纳米管质量分数分别为0.04%、0.3%和0.3%,聚合温度75℃时,所合成树脂的吸水性能最佳。添加碳纳米管后树脂表面粗糙和形成孔结构导致了其吸水性能的变化,使得碳纳米管/聚丙烯酸钠的吸水量和吸水速率明显提高,其吸去离子水和生理盐水能力分别达到1423和104g/g。该树脂重复吸水5次后,其吸水能力为1081.5g/g,达到最大吸水倍数的76.0%。     

丙烯酸酯类吸油树脂的合成与性能研究

以丙烯酸酯、甲基丙烯酸酯为主要单体,二丙烯酸丁二醇酯为交联剂,过氧化二苯甲酰为引发剂,采用悬浮聚合方法,合成聚丙烯酸酯类高吸油树脂.研究了分散剂、引发剂、交联剂用量及单体配比等因素对树脂吸油性能的影响.结果表明,分散剂用量为单体质量的0.12%,引发剂用量为1.0%,交联剂用量为1.5%时树脂的吸油能力最佳,吸甲苯倍率可达15倍,吸汽油倍率可达10倍,吸机油倍率可达近9倍.     

淀粉接枝丙烯酸/醋酸乙烯酯高吸水性树脂的制备

以过硫酸铵为引发剂,N,N-亚甲基双丙烯酰胺为交联剂,淀粉与丙烯酸/醋酸乙烯酯混合单体通过接枝共聚,制备了吸水及耐盐性能均较好的淀粉接枝丙烯酸/醋酸乙烯酯高吸水性树脂(CGAV)。最佳工艺条件为:淀粉10.0 g,m(混合单体)∶m(淀粉)=4∶1,w(引发剂)=0.3%,w(交联剂)=0.05%,于45℃反应2h~3 h。在最佳工艺条件下制得的CGAV吸去离子水率760 g.g-1,吸0.9%NaC l水溶液率68 g.g-1。     

Preparation of a biodegradable superabsorbent polymer and measurements of changes in absorption properties depending on the type of surface‐crosslinker

A superabsorbent polymer (SAP) is a special polymer material that can absorb up to 500 times its own weight of pure water, but has a problem that it does not biodegrade itself and cause environmental pollution. Therefore, we aim to prepare a biodegradable SAP by using biomass‐based IA. The SAP must be able to retain absorbed water and absorb water under a given pressure. We have carried out studies to improve the surface hardness of the SAP to enhance absorption of water under a given pressure by surface‐crosslinking. Four types of surface‐crosslinkers, ethylene glycol diglycidyl ether (EGDGE), ethylene carbonate (EC), 1,4‐butanediol (BD), or glycerol, were used. We confirmed the water absorption capacity of the SAP by measuring its centrifuge retention capacity (CRC) and absorbency under load (AUL). The structural characteristics of the SAP were confirmed by attenuated total reflection (ATR) and X‐ray photoelectron spectroscopy (XPS), and the surface characteristics were confirmed by scanning electron microscopy (SEM).     

固化条件对聚合物分散液晶膜电光性能的影响

选用聚乙二醇二缩水甘油醚(EGDE)/季戊四醇缩水甘油醚(PERTGE)/1,8-二氨基-3,6-二氧杂辛烷(EDBEA)/向列相液晶(SLC1717)复合体系,在不同的固化条件下,通过热聚合诱导相分离方法制备了一系列电光性能不同的聚合物分散液晶(polymer dispersed liquid crystal,简称PDLC)膜.研究了固化温度和固化时间对制备的PDLC膜中聚合物网络的微观形貌和电光性能的影响.结果表明,随着固化温度的升高以及固化时间的缩短,PDLC膜的对比度、驱动电压和开态响应时间逐渐增大,而关态响应时间逐渐减小.在固化温度为363.2 K,固化时间为7 h时,所制备的PDLC膜具有较佳的电光性能.     

Radiation Synthesis of Superabsorbent Hydrogels Based on Chitosan and Acrylic Acid for Controlled Drug Release

Superabsorbent hydrogels based on the natural polymer chitosan and acrylic acid (CS/AAc) was prepared using ⁶⁰Co gamma radiation as a source of initiation and crosslinking. The factors, which affect the preparation of CS/AAc hydrogels such as irradiation dose, CS/AAc ratios, and acrylic acid monomer concentrations, to get the best optimum conditions, were investigated. The kinetic studies of the swelling of CS/AAc hydrogel showed that it follows a Fickian type of water diffusion. The Fickian constant value ‘n’ was more than 0.5 with a high swelling capacity of 300 g/g as superabsorbent hydrogel. In addition, the suitability of CS/AAc hydrogel as carrier material for the drug Chlortetracycline-HCl has been investigated by adsorption isotherm studies. The performance of drug release from hydrogel systems, influenced by acrylic acid ratio and the effect of pH of the medium was studied.     

乙二醇二缩水甘油醚的合成及作为阳离子型紫外光固化稀释剂性能研究

以三氟化硼乙醚络合物为催化剂,以氢氧化钠为成环反应的闭环剂,利用乙二醇和环氧氯丙烷为原料合成了乙二醇二缩水甘油醚.研究了催化剂三氟化硼乙醚络合物用量、环氧氯丙烷和乙二醇摩尔比、氢氧化钠和乙二醇摩尔比,以及成环反应温度这些因素对合成反应的影响.结果表明较好的合成反应条件是:三氟化硼乙醚络合物质量分数为0.40%,环氧氯丙烷和乙二醇较佳摩尔比为2.4:1,氢氧化钠和乙二醇较佳摩尔比为2.2:1,较佳的成环反应温度为30℃.同时,把乙二醇二缩水甘油醚作为稀释剂加入到环氧树脂E-51中,利用三芳基锍鎓六氟锑酸盐作为引发剂,制备了阳离子型紫外光固化涂料,其紫外光固化膜的拉伸强度为46.25MPa,杨氏模量为1487.26MPa,断裂伸长率为6.27%.     

丙烯酸与海藻酸钠共聚制备耐盐性高吸水树脂

丙烯酸与海藻酸钠共聚制备耐盐性高吸水树脂     

Stabilization of water/n‐hexane emulsions by amphiphilic copolymers based on vinyl ethers and their polycomplexes with poly(acrylic acid)

Amphiphilic random copolymers based on vinyl ether of ethylene glycol and vinyl butyl ether as well as their polycomplexes with poly(acrylic acid) were studied as polymeric reagents for the stabilization of water/n‐hexane emulsions. The emulsion stability strongly depended on the content of vinyl butyl ether in the copolymers as well as their concentration in solution. The more hydrophobic copolymers stabilized emulsions more efficiently. An increase in the temperature and the addition of inorganic salts reduced the emulsion lifetime. The formation of interpolymer complexes between the copolymers and poly(acrylic acid) significantly influenced the stability of the emulsions. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2625–2632, 2004     

Surface Modification of Ultra-high Molecular Weight Polyethylene Membranes Using Underwater Plasma Polymerization

Ultra-high molecular weight polyethylene membranes were modified and subsequently polymer coated using the underwater plasma produced by glow discharge electrolysis. This plasma pretreatment generated various O-functional groups among them OH groups have dominated. This modified inner (pore) surface of membranes showed complete wetting and strong adhesion to a hydrogel copolymerized by glow discharge electrolysis also. The deposited hydrogel consists of plasma polymerized acrylic acid crosslinked by copolymerization with the bifunctional N,N′-methylenebis(acrylamide). Tuning the hydrogel hydrophilicity and bio-compatibility poly(ethylene glycol) was chemically inserted into the copolymer. Such saturated polymer could only be inserted on a non-classic way by (partial) fragmentation and recombination thus demonstrating the exotic properties of the underwater plasma. The modification of membrane was achieved by squeezing the reactive plasma solution into the pores by plasma-induced shock waves and supported by intense stirring. The deposited copolymer hydrogel has filled all pores also in the inner of membrane as shown by scanning electron microscopy of cross-sections. The copolymer shows the characteristic units of acrylic acid and ethylene glycol as demonstrated by infrared spectroscopy. A minimum loss in carboxylic groups of acrylic acid during the plasma polymerization process was confirmed by X-ray photoelectron spectroscopy. Additional cell adhesion tests on copolymer coated polyethylene using IEC-6 cells demonstrated the bio-compatibility of the plasma-deposited hydrogel.     

Biosorption studies of uranium (VI) on cross-linked chitosan: isotherm,kinetic and thermodynamic aspects

The cross-linked chitosan (CS) gels synthesized by using glutaraldehyde (GLA), epichlorohydrin (EC), and ethylene glycol diglycidyl ether (EGDE) as cross-linkers respectively were used to investigate the adsorption of U(VI) ions in an aqueous solution. The pure chitosan (PCS) and the cross-linked chitosan gels were characterized by FTIR and SEM analysis. The kinetic, thermodynamic adsorption and adsorption isotherms of U(VI) ions onto unmodified and modified cross-linked chitosan were studied in a batch adsorption experiments. The effect of pH, contact time and temperature on the adsorption capacity were also carried out. At the optimum pH, the maximum adsorbed amount of PCS, GLACS, ECCS and EGDECS were 483.05, 147.05, 344.83 and 67.56 mg/g, respectively. The uranium (VI) adsorption process of PCS and ECCS followed better with pseudo-second-order kinetic model, while GLACS and EGDECS followed pseudo-first-order kinetic model well. The results obtained from the equilibrium isotherms adsorption studied of U(VI) ions were analyzed in two adsorption models, namely, Langmuir and Freundlich isothms models, the results showed that the Langmuir isotherm had better conformity to the equilibrium data. The thermodynamic parameters such as enthalpy (ΔHo), entropy (ΔSo), and Gibbs free energy (ΔGo) showed that the adsorption process was both spontaneous and endothermic.     

Synthesis and properties of poly(acrylamide‐co‐acrylic acid)/polyacrylamide superporous IPN hydrogels

Poly(acrylamide‐co‐acrylic acid)/polyacrylamide [P(AM‐co‐AA)/PAM] hydrogel with superporous and interpenetrating network (IPN) structure was prepared by a prepolymerization reaction and a synchronous polymerization reaction and frothing process. Scanning electron microscope (SEM) images show that the resultant hydrogel possesses abundant interconnected pores. DSC indicates that the porous structure enhances the swelling ratio and reduces the interaction between water and the hydrogel. In contrast, the IPN by PAM decreases water absorbency and enhances water retentivity. It is found that a superporous stucture in the hydrogel increases the equilibrium swelling ratio and decreases the compressive strength of the hydrogel. On the other hand, the increase in AM oligomer (oligo‐AM) amount decreases the equilibrium swelling ratio and improves the compressive strength of the hydrogel. Therefore, the two‐steps synthesis method can be used to construct a hydrogel with superporous and IPN structure. The swelling and mechanical properties of the hydrogel can be improved effectively. Copyright © 2008 John Wiley & Sons, Ltd.     

Superabsorbent hydrogel composites

A new cost‐effective approach to enhance gel strength of superabsorbent hydrogels was invented. Superabsorbent hydrogel composites (SHCs) were prepared through an optimized rapid solution polymerization of concentrated partially neutralized acrylic acid in the presence of a crosslinking agent under normal atmospheric conditions. Kaolin was used as an inorganic component in the polymerization process to strengthen the hydrogel products. FT‐IR spectroscopy was used to confirm grafting of acrylic chains on to the surface of kaolin particles. Morphology of the products was studied by scanning electron microscopy (SEM). Compared with the kaolin‐free hydrogel (control), kaolin caused a reduced equilibrium swelling and swelling rate as low as 17–31% and 19–29%, respectively. Kaolin, however, resulted in enhanced gel strength as high as 21–35% compared to the control. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to study thermal properties of the composites. The SHCs exhibited higher thermal stability than the control. Meanwhile, changes in certain thermal transitions reconfirmed the chemical interaction of the acrylic chain with kaolin. These thermostabilized strengthened superabsorbent hydrogels may be considered as good candidates for agricultural application to retain more water under soil pressure. Copyright © 2003 John Wiley & Sons, Ltd.