CMC-g-PAA/APT/HA复合高吸水性树脂的制备与溶胀性能

以羧甲基纤维素(CMC)为基质,丙烯酸(AA)为单体,凹凸棒黏土(APT)和腐植酸(HA)为复合组分,采用水溶液聚合法制备了羧甲基纤维素接枝聚丙烯酸/凹凸棒黏土/腐植酸(CMC-g-PAA/APT/HA)环境友好复合高吸水性树脂,用红外光谱(FTIR)进行了结构表征。考查了APT和HA含量对树脂吸水倍率和吸水速率的影响,研究了树脂在不同pH溶液中的溶胀行为以及反复吸水性能。试验结果表明,APT和HA通过其表面的活性基团参与了接枝共聚反应,在体系中引入HA和APT能够显著提高复合高吸水性树脂的吸水能力。在HA含量为5%(质量分数),APT含量为30%(质量分数)时,树脂可达到最优吸蒸馏水倍率为582g/g。该复合高吸水性树脂在pH值在4～11范围内时具有较高的吸水性能,表现出优异的pH稳定性。经过5次反复溶胀后,该复合吸水树脂仍能达到424g/g的吸水倍率,较不含APT和HA样品提高了近44%。     

醚化海藻酸钠-丙烯酸二元共聚物的合成与溶胀特性

以醚化海藻酸钠(ESA)和丙烯酸(AA)为原料,溶液聚合法合成了一种二元高吸水共聚物。红外光谱对产物进行了表征,通过SEM观察了接枝体系的微观相态结构。探讨了产物的溶胀性能。研究发现,最佳醚化度(D s)应控制在0.2~0.5;当交联剂、引发剂占总单体的质量分数均为0.2%,ESA占总单体的质量分数小于20%,D s=0.25时,产物在去离子水中的吸水倍率最高可达398 g/g,而在w(NaC l)=0.9%的盐水中的吸水倍率均在77 g/g左右;在以上条件下,产物的吸水倍率随w(ESA)的增加而增大。聚合物在不同pH介质中呈现体积相转变特性,在酸性介质中收缩,在中性和碱性介质中溶胀,5次循环实验的结果表明,树脂在酸性、中性和碱性介质中的吸水倍率平均分别为61、65和82 g/g。     

GA-g-PAMPS/APT复合高吸水性树脂的合成和溶胀行为

以阿拉伯胶(GA)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、凹凸棒石黏土(APT)为原料,采用微波辐射法,通过接枝共聚合成生物质GA-g-PAMPS/APT高吸水性树脂。利用FTIR、XRD和TG分析了树脂的结构和热稳定性能,探讨了树脂在各种盐溶液和不同p H溶液中的溶胀行为,研究了树脂的溶胀速率和反复吸水性能。结果显示:GA、APT与AMPS之间发生了接枝共聚反应,w(GA)=7.5%、w(APT)=10%时树脂在去离子水和生理盐水中的最大吸水倍率分别为783 g/g和91 g/g。树脂在各种盐溶液和不同p H溶液中表现出良好的响应性和可逆性能。适量引入APT能显著提高树脂的热稳定性、溶胀速率、反复吸水性能和p H稳定性。     

CMC-g-PAMPS/APT复合高吸水树脂的溶胀行为及热稳定性能

以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为单体,凹凸棒黏土(APT)和羧甲基纤维素钠(CMC)为复合组分,采用微波辐射方法制备了CMC-g-PAMPS/APT环境友好复合高吸水性树脂。考察了APT用量对树脂吸水速率、保水性能和反复吸水性能的影响,利用XRD和TG等方法分析了该树脂的结构及其热稳定性能。结果表明,APT和CMC参与了接枝共聚反应,其反应仅在APT的表面进行,单体并没有插入到APT的层间。在APT质量分数为7.5%时,树脂的分解温度主要在250℃以上,具有良好的热稳定性。经过5次反复溶胀后,树脂的吸水倍率较不含APT的树脂提高了近42%。在体系中引入APT能显著提高树脂的吸水速率和保水性能。     

Porous Superabsorbent Hydrogel Composites: Synthesis,Morphology and Swelling Rate

Summary: Novel porous hydrogel composites with very high swelling capacity and enhanced rate of water absorption were synthesized in aqueous media at room temperature under normal atmospheric conditions. The porosity was induced through either foaming conducted in the course of polymerization or non‐solvent dewatering of the as‐synthesized gels. Kaolin was incorporated as an inorganic component in the polymerization process. The foaming technique was used to form porosity using three systems of different porogens (porosity generators), i.e. sodium bicarbonate, acetone and their combination. The as‐synthesized gels were dried through oven drying and non‐solvent dewatering. Morphology and swelling rate of the superabsorbent hydrogel composites (SHCs) were studied versus either the porogen system or the drying method. It was found that the simultaneous polymerization‐foaming technique had great influence on the improvement of porosity, morphology of the porous structure and the rate of water absorption. It was also shown that the drying procedure had remarkable influence on preserving the preformed porosity. Methanol as a dewatering solvent produced SHCs with higher porosity and swelling rate in comparison with the porosity of the hydrogels dewatered in acetone. Our invented methodology including simultaneous polymerization and foam formation using dual‐porogen system and the subsequent methanol‐dewatering approach was found to be the most efficient, highly practical, and cost‐effective route for preparing improved superabsorbing hydrogel materials.

     

马铃薯废渣/聚丙烯酸/坡缕石黏土高吸水树脂的制备及表征

采用马铃薯废渣(PWR,粒径<180目)作为纤维素和淀粉源,过硫酸钾(KSB)为引发剂,N,N'-亚甲基双丙烯酰胺(MBA)为交联剂,复配坡缕石(PGS)黏土,与部分中和的丙烯酸(AA)通过自由基引发在水溶液中接枝共聚制备低成本PWR-g-PAA/PGS高吸水树脂。借助扫描电镜(SEM)、红外光谱(FTIR)及热重分析(TGA)对高吸水树脂的形貌、结构及热稳定性进行了表征和分析,并测试其吸液性能。结果表明,当坡缕石黏土和马铃薯废渣的用量占反应体系总质量的17.5%时,WPR-g-PAA/PGS高吸水树脂对w(NaCl)=0.9%水溶液、蒸馏水的最大吸收量分别为41.0、538.6 g/g,保水率为96.1%,凝胶强度达11.3 kPa。通过高吸水树脂的吸水溶胀过程确定了材料的吸水动力学行为符合non-Fickon扩散模型。     

聚偏氟乙烯/有机累托土纳米复合超滤膜的制备、表征和性能研究

用溶液插层法制备了聚偏氟乙烯(PVDF)/有机累托土(OREC)纳米复合超滤膜,研究了OREC含量对复合膜力学性能、表面粗糙度、微观形貌、结晶行为和亲水性的影响,并测定了复合膜的性能。结果表明:OREC的加入对复合膜微观形貌有重要影响,使膜的孔隙率从44.6%增加至71.3%;OREC的加入有利于PVDF中亲水性β相的生成,在其含量较高时能显著提高复合膜的表面粗糙度和表面亲水性,并能同时提高复合膜的纯水通量和蛋白截留率;刚性OREC片层的加入,能显著改善复合膜的力学性能,对弹性模量的增强尤为明显,可达纯PVDF膜的5.8倍。     

海藻酸钠接枝丙烯酸-丙烯酰胺共聚物/凹凸棒石复合材料的制备与表征

以凹凸棒石(AT)为原料、过硫酸钾为引发剂、N,N-亚甲基双丙烯酰胺为交联剂、丙烯酰胺(AM)、丙烯酸(AA)两种单体同时对海藻酸钠(SA)进行接枝改性,采用水溶液聚合法制备了海藻酸钠接枝丙烯酸-丙烯酰胺共聚物/凹凸棒石复合材料。考察了各合成因素对复合材料吸液倍率的影响,并采用FTIR、SEM对复合材料进行了表征。结果表明,当丙烯酰胺与丙烯酸的质量比为5 1∶、海藻酸钠质量分数为15%(占单体丙烯酸质量,下同)、凹凸棒石用量为25%、交联剂用量为0.095%、引发剂用量为0.55%和反应温度为80℃时,制备的复合材料的吸蒸馏水倍率最高,达到1 693.3 g/g。FTIR表明,海藻酸钠、丙烯酸、丙烯酰胺和凹凸棒石共同参与了接枝聚合反应。SEM表明,凹凸棒石的引入,复合材料的表面致密但存在大小不一的孔隙,有利于提高复合材料的吸液倍率。     

聚乙烯醇/聚丙烯酸/腐植酸钠高吸水性树脂的制备及溶胀行为

以N,N＇-亚甲基双丙烯酰胺为交联剂、过硫酸铵为引发剂,采用水溶液聚合法合成了聚乙烯醇/聚丙烯酸/腐植酸钠多功能高吸水性树脂。研究了聚乙烯醇和腐植酸钠含量对树脂吸水倍率的影响,同时考察了树脂的吸水速率、溶液pH值对吸水倍率的影响及反复溶胀性能。结果表明,在体系中引入廉价的腐植酸钠,能够显著提高树脂的吸水能力。在腐植酸钠含量为10wt%时,树脂具有最高的吸水倍率,其吸蒸馏水和0.9wt%NaCl溶液分别达到1020g/g和80g/g。     

硬脂酸改性纳米纤维素晶体/纳米ZnO复合材料的制备与表征

通过硫酸水解微晶纤维素法制备纳米纤维素晶体(CNC),将其与一定量的纳米氧化锌复合制得复合材料;然后使用一定量的硬脂酸对复合材料进行改性,并将所得改性后的溶胶在120℃下鼓风干燥2 h,即可得到硬脂酸改性的CNC/纳米ZnO复合疏水材料。并采用X-射线衍射仪、场发射扫描电镜、傅里叶红外光谱和接触角分析仪对复合材料的表面形貌和疏水性进行了表征及揭示。结果表明,CNC/纳米ZnO复合材料构成微/纳米双重粗糙结构,经硬脂酸表面改性后引入了憎水基团甲基,使其具备一定的疏水性能,在最优制备工艺条件下疏水角可高达到145.6°。     

凹土基有机-无机复合高吸水性材料的制备及性能研究

应用水溶液聚合法,以丙烯酰胺和未纯化凹凸棒原土为原料制备了丙烯酰胺/凹凸棒土复合吸水性材料,考察了凹凸棒原土含量、交联剂含量和引发剂含量对复合吸水材料吸水性能的影响,并对制备条件进行了优化。结果表明当凹凸棒原土质量分数为10%,交联剂质量分数为0.06%,引发剂质量分数为0.4%时,复合吸水材料在蒸馏水中的吸水倍率最高,达到了719 g/g。     

Swelling Behaviors of a New Zwitterionic N-carboxymethyl-N, N-dimethyl-N-allylammonium/acrylic Acid Hydrogel

A series of new zwitterionic N-carboxymethyl-N,N-dimethyl-N-allylammonium (CDMA)/acrylic acid (AA) copolymer hydrogels with different contents of anionic and cationic groups were prepared by aqueous polymerization to investigate their swelling behaviors. Various factors, including the solution pH, the various salt solution, temperature, were studied. The dynamics parameters were also calculated. The swelling capacity, as well as salt-tolerant ability increases with increasing N content in the dilute solution of salts. The hydrogel with 2.43% N and 49.54% COOH reaches 773 g/g swelling capacity. CDMA/AA copolymer gel can improve the pullulating rate of wheat remarkably, which makes them good candidates for considering as potential soil-improvement agent.     

Synthesis and Characterization of Poly (CMC-g-cl-PAam/Zeolite) Superabsorbent Composites for Controlled Delivery of Zinc Micronutrient: Swelling and Release Behavior

A series of novel superabsorbent hydrogel composites, poly(CMC-g-cl-PAam/Zeolite) (ZSAPC) were prepared by in situ graft polymerization using a cellulosic backbone, acrylamide and natural zeolite. The swelling and deswelling behavior of the prepared composites was evaluated and analyzed by different empirical models. The composite with optimum water absorption capacity were impregnated with ZnSO₄ in situ during polymerization reaction. Zincated composites showed less water absorption capacity as compared to non-zincated ones. Zinc release behavior of zincated test hydrogel composites was studied in water and soil. All the test compositions exhibited non-Fickian or anomalous transport (0.43 < n < 0.84) and behaved as slow release products.     

有机累托石/环氧树脂(OREC/EP)复合材料的制备和性能研究

用单体原位插层技术制备了有机累托石/环氧树脂(OREC/EP)复合材料,考察了OREC的加入及其含量对复合材料OREC/EP体系的力学性能、耐介质性能和耐紫外线性能的影响。研究发现:OREC是一种良好的环氧树脂增韧改性剂,OREC的加入可改善复合材料的综合性能。当OREC质量分数为3%时,冲击强度和弯曲强度提高幅度最大,分别为6.25%和8.39%,耐海水性能效果最好;在添加质量分数为1%~7%时,复合材料体系的耐酸(碱)和耐紫外线性能均随OREC含量的增加而上升。     

Sodium alginate/Na+‐rectorite composite films: Preparation,characterization, and properties

Rectorite (REC), one kind of layered silicates, has been applied to polymers to improve their properties. The sodium alginate (SA) layered silicate is a new option to modify the properties of polysaccharides. In this article, SA was modified by Na⁺‐rectorite (Na⁺REC). The chemical structures and microstructures of Na⁺REC and Na⁺REC modified SA (SA/Na⁺REC) were analyzed by using Fourier transform infrared spectrometer and X‐ray diffraction. The morphologies of SA/Na⁺REC composites were observed by using scanning electron microscopy and transmission electron microscopy. The mechanical and anti‐ultraviolet properties as well as thermal properties of SA/Na⁺REC composites were investigated. The results show that the properties of pure SA film can be improved by the addition of Na⁺REC, and SA/Na⁺REC composite containing 2 wt % Na⁺REC has the best intercalation effect and optimum comprehensive properties among the prepared composites in this article. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

EVA/有机改性累托石复合泡沫材料的制备与性能研究

采用十二烷基三甲基溴化铵（DTAB）对累托石（REC）进行有机处理制备出有机改性累托石（OREC）,通过熔融插层法制备出了乙烯-醋酸乙烯共聚物/有机改性累托石（EVA/OREC）复合泡沫材料。利用傅里叶红外光谱仪（FTIR）、X射线衍射仪（XRD）、扫描电子显微镜（SEM）、万能试验机等对复合材料的形貌和力学性能进行了表征,研究了累托石的层间距、含量对复合泡沫材料力学性能的影响。结果表明,经有机改性后累托石层间距增加了10.9 %;复合材料的拉伸强度、断裂伸长率、撕裂强度也随之明显升高;且当OREC质量组分为10份时材料的各项力学性能达到最佳。     

淀粉接枝丙烯酸/丙烯酰胺耐盐型高吸水性树脂的制备

以淀粉为主要原料,丙烯酸（AA）和丙烯酰胺（AM）为接枝单体,采用水溶液聚合法制备具有耐盐型高吸水性树脂。探讨了原料配比、丙烯酸中和度、反应温度等因素对产物吸水性能的影响,结果表明,在聚合温度为50℃,淀粉、丙烯酰胺、引发剂和交联剂用量分别为丙烯酸用量的15%、40%、2.4%和0.03%的条件下,所制备的耐盐型高吸水...     

粘土/聚丙烯酸（钾）复合材料的制备及性能研究

以部分中和的丙烯酸单体为原料,分别添加海泡石、蒙脱石、凹凸棒石,采用溶液聚合法制备粘土/聚丙烯酸（钾）复合材料,并制备粘土/聚丙烯酸（钾）包膜复合肥。探讨粘土种类、添加量对复合膜材料吸水倍率的影响。采用红外光谱对复合膜材料的结构进行表征。结果显示：海泡石、凹凸棒石和蒙脱石的添加量分别在2%、5%和10%时,复合材料的吸水倍率达到最大值;包膜肥料中N、P和K均具有较好的缓释效果。     

纳米羟基磷灰石／聚氨酯复合材料的制备与表征

以模拟体液（SBF）为介质,采用仿生法制备了纳米羟基磷灰石（n-HA）,通过原位聚合法制备了纳米羟基磷灰石／聚氨酯（n-HA／PU）复合材料。利用x射线衍射（XRD）、红外光谱（FT-IR）、热重分析（TGA）、扫描电镜（SEM）研究了n—HA和复合材料的结构和热稳定性、表面形貌特征。结果表明,在SBF中用浓度为0．200mol／L硝酸钙溶液制备出具有良好结晶度的n-HA,由此制备的n—HA／PU复合材料开孔率良好,有望成为一种性能良好的医用组织支架材料。     

腐殖酸改性聚丙烯酸高吸水性树脂制备及性能研究

以丙烯酸(AA)为单体,腐殖酸(HA)为改性剂,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,过硫酸铵(APS)为引发剂,采用表面交联法制备腐殖酸改性聚丙烯酸树脂.在腐殖酸用量、交联剂用量、甲醇/水体积比、反应温度等参数的优化条件下,制得了腐殖酸改性聚丙烯酸高吸水性树脂,树脂吸水倍率达1093 g/g,吸盐水倍率达99.2 g/g.