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81.
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 相似文献
82.
魔芋超强吸水剂的生物降解性能研究 总被引:1,自引:0,他引:1
采用霉菌侵蚀法和土壤掩埋法对自制的吸水性材料魔芋超强吸水剂(KSAP)的生物降解性能进行了研究.结果表明,KSAP在霉菌侵蚀和土壤掩埋的条件下均具有可生物降解性,它的使用可减少环境污染. 相似文献
83.
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85.
预处理方式对小麦秸秆制备高吸水性树脂的影响 总被引:5,自引:2,他引:5
以小麦秸秆为原料合成高吸水性树脂需首先对秸秆进行预处理,通过实验分析,比较了预处理方式如酸处理、碱浸泡、氨水浸泡、碱蒸煮及其联合处理对秸秆及高吸水性树脂的影响;用晶相显微镜、IR等表征了处理前后秸秆的微观形貌、化学结构及树脂的化学结构等;结果表明,比较理想的预处理方式是碱蒸煮处理〔w(NaOH)=14%的水溶液、150℃、0.6 MPa、30 m in〕结合浓度为1 mol/L的硝酸在100℃下处理30 m in,及w(NH3.H2O)=10%的氨水室温浸泡48 h结合浓度为1 mol/L的硝酸在100℃下处理45 m in;两种方式所得高吸水性树脂吸收纯水的质量倍率分别为405 g/g和293 g/g,吸收w(复混肥)=0.1%的水溶液的质量倍率分别为124 g/g和82g/g〔复混肥中w(N)=w(P)=w(K)=10%,N、P、K分别以尿素、过磷酸钙、氯化钾存在〕。 相似文献
86.
A kind of novel superabsorbent hydrogel with high swelling ratio property that could be used for the development of water absorbing resin, soil water retention agent, and chemical sand‐fixing material was synthesized in this study. The hydrogels were prepared by the crosslinking reaction of polysuccinimide (PSI). The relationships between swelling ratio and volume of solvent as well as the concentration of crosslinking agent were investigated in detail. Several composites, such as starch, carrageenan, and polyacrylamide, were added into hydrogels to enhance the swelling ratio. It was found that the swelling ratio was significantly increased, which the maximum water absorbency was enhanced 2.46 times when the composite polyacrylamide (PAM) was added compared to the control. The effects of ionic strength and sensitivity of pH on hydrogels were also studied. The modified hydrogels products with swelling ratio less sensitivity to the salinity as well as relative high swelling ration in salinity system were also obtained by adding PAM. Through the Fourier transform infrared spectroscopy (FTIR) characterizations, the crosslinking reaction mechanism and the structure of composite were proposed. In addition, the transmission electron microscopy (TEM) examinations showed that some composite materials elevated the physical crosslinked and connected channels density substantially. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 550–557, 2006 相似文献
87.
高吸水树脂因其优良的吸水性和保水性,近年来受到广泛关注与研究。为实现柚子皮的废物利用,优化高吸水树脂的生产工艺,研究以天然无毒的柚子皮粉为接枝骨架,丙烯酸为接枝单体,司班-80为分散剂,环己烷为油相,过硫酸钾为引发剂,N,N’-亚甲基双丙烯酰胺为交联剂,采用反相悬浮聚合法制备了吸水性和吸生理盐水性能良好的纤维素基高吸水树脂。探讨了司班-80用量、引发剂用量、柚皮粉用量、交联剂用量、丙烯酸中和度、反应温度、油水质量比对树脂在蒸馏水和生理盐水中的吸液倍率的影响。结果表明,在司班-80用量为单体的6.7%,引发剂用量为单体的0.5%,柚皮粉:丙烯酸为1:5,交联剂为单体的0.67%,丙烯酸中和度40%,油水比2:1,反应温度80℃条件下,树脂对蒸馏水和生理盐水最大吸液倍率可达362.29 g/g和42.49 g/g。 相似文献
88.
89.
在室温下,利用酸碱中和热引发聚合反应,以丙烯酸(AA)和丙烯酰铵(AM)为共聚单体,分别以过硫酸钾(KPS)为氧化剂、亚硫酸钠(CAS)为还原剂,N,N-亚甲基双丙烯酰胺(NMBA)为交联剂,采用水溶液聚合法制取聚丙烯酸-丙烯酰胺高吸水性树脂(PAMA)。通过正交设计实验探讨该吸水性树脂合成的主要影响因素及优选制备工艺条件。实验表明:在AM用量1.575g,KPS 0.079g,CAS 0.095g,NMBA 0.047g,中和度80%的条件下,制得的PAMA其吸水倍率可达622g/g,吸盐倍率85g/g。 相似文献
90.
The purpose of this study was to prepare modified-release dosage of indomethacin (IND) in the form of micromatrices based on a superabsorbent hydrogel (SAH), poly(acrylic acid), partly sodium salt-g-poly(ethylene oxide) (PAAc-Na-g-PEO). A soaking procedure was used for the preparation of drug-loaded hydrogel micromatrices. The amount of IND, volume of drug-loading solution, and amount of PAAc-Na-g-PEO granules used for preparing micromatrices were the independent factors. The dependent factors were the measured responses from micromatrices, that is, percent recovery, percent entrapment efficiency, and the time at which 63.2% of the drug was released (Td, minutes). A three-factor, three-level full factorial design (33) was created to optimize formulations. Nonlinear regression analysis indicated a good correlation between the measured responses and the independent factors. Optimum responses were obtained from medium levels of IND and SAH and low level of drug-loading solution. Differential scanning calorimetry, X-ray diffraction analysis, and scanning electron micrography indicated that IND crystals are physically adsorbed into the pores and irregular spaces of the hydrogel. 相似文献