反相悬浮聚合法合成可生物降解海藻酸钠高吸水性树脂

以丙烯酸(AA)和海藻酸钠(SA)为原料,用反相悬浮聚合法合成了聚丙烯酸钠/海藻酸钠高吸水性树脂。研究了海藻酸钠、引发剂(KPS)和交联剂(NMBA)用量、丙烯酸中和度、聚合反应温度等因素对树脂吸水率的影响以及树脂的生物降解性能。结果表明,当w(SA)=1.5%、w(KPS)=0.15%、w(NMBA)=0.1%、丙烯酸中和度为65%、聚合反应温度为75℃时,树脂对蒸馏水的吸水率为845 g/g,对生理盐水的吸水率为88 g/g,且能被土壤和微生物降解,w(SA)=10%的树脂在60 d内能够被芽苞杆菌降解52%,在土壤中能被降解36%,且降解速度随海藻酸钠质量分数的增加而加快。IR测定表明,树脂为丙烯酸盐与海藻酸钠的接枝共聚物。SEM测定表明,PAA/SA高吸水性树脂呈花瓣结构。     

聚丙烯酸-海藻酸钠吸水树脂的制备及性能研究

以丙烯酸为单体,海藻酸钠为接枝物,添加丙烯酰胺,通过溶液聚合法制备复合型耐盐高吸水性树脂。研究了聚丙烯酸-海藻酸钠高吸水树脂的吸水性能。结果表明,在蒸馏水、生理盐水中吸水倍率分别达到830 g/g、81 g/g。天然高分子海藻酸钠具有很好的耐盐性,海藻酸钠的加入,提高了高吸水性复合材料的耐盐性。     

聚丙烯酸/海藻酸钠高吸水性树脂的制备及生物降解性能

用过硫酸钾(KPS)作引发剂、通过水溶液聚合法制得了可生物降解的聚丙烯酸盐/海藻酸钠高吸水性树脂.研究了海藻酸钠(SPM)及引发剂用量、丙烯酸（AA）中和度(D_n)、聚合反应温度(T)等因素对树脂吸水率的影响以及树脂的生物降解性能.当海藻酸钠的质量分数W_SPM为1.5%,过硫酸钾的质量分数W_KPS为0.15%,中和度为65%,反应温度为70℃时,共聚物蒸馏水的吸水率为812 g•g^-1,生理盐水的吸水率为79 g•g^-1,且能被土壤和特定微生物降解,在土壤中60 d的降解率达17.36%.     

淀粉接枝丙烯酸高吸水性树脂制备及性能研究

以淀粉和丙烯酸为主要原料通过共聚反应制备淀粉接枝高吸水性树脂,研究了淀粉种类对高吸水性树脂性能的影响,并对高吸水性树脂进行生物降解实验.结果表明,高吸水性树脂的吸水率达到1079 g/g,60℃下8 h的保水率约为15%,在土壤中35 d后其降解率为29%.     

聚丙烯酸钠高吸水性树脂的改性研究进展

从提高聚丙烯酸钠高吸水性树脂的凝胶强度以及耐盐性和稳定性、改善降解性能、控制吸水速度等方面,对聚丙烯酸钠高吸水性树脂的改性方法进行了综述,提出改性工艺研究和改性原理研究、实现高功能化聚丙烯酸钠高吸水性树脂的分子水平设计,是聚丙烯酸钠高吸水性树脂改性研究的重要方向。     

聚丙烯酸盐类高吸水性树脂的合成研究

以部分中和的丙烯酸为基本单体，采用反相悬浮聚合法，对聚丙烯酸钾、聚丙烯酸铵高吸水性树脂的合成条件进行了研究，获得了吸水树脂的吸液率与交联剂用量、引发剂用量、pH值等影响因素的关系，并利用共聚方法改进了吸水树脂的耐盐性，研制出了性能优良的高吸水性树脂。所制高吸水性树脂吸去离子水倍率≥1200mL/g（最高达2700mL/g)；耐盐性高吸水性树脂吸0．9％ NaCl水溶液倍率≥150mL/g(最高达260mL/g)。     

聚丙烯酸钠高吸水性树脂的研究

采用反相悬浮聚合法合成聚丙烯酸钠高吸水性树脂。讨论了水油比、分散剂种类、交联剂用量、引发剂用量、反应温度、中和度及反应时间对树脂吸水率的影响，并研究了其保水率。在最佳条件下合成的聚丙烯酸钠树脂吸水率达606％，在80℃干燥4h保水率仍达83％，该吸水性树脂还可回收再利用。     

聚丙烯酸钠/高岭土复合高吸水性树脂的制备、结构与性能

以丙烯酸和高岭土为原料,用反相悬浮聚合法合成了聚丙烯酸钠/高岭土复合高吸水性树脂。研究了加入高岭土的聚丙烯酸钠复合高吸水性树脂合成中反应温度、中和度、交联剂用量、引发剂用量、高岭土添加量等影响树脂吸水性能的主要因素。结果表明,用反相悬浮聚合法合成的复合高吸水性树脂后处理容易,树脂的吸水率达到512g/g,吸盐水率达到81g/g,吸水速度比不加高岭土提高20%,保水能力提高15%,在250℃加热30min仍能保持原吸水率的95%。用IR和TEM研究了复合高吸水性树脂的表面和结构,TEM显示高岭土的加入对树脂颗粒大小和形状有较大的影响,IR初步表明聚丙烯酸与高岭土产生了交联。     

聚丙烯酸钠∕高岭土复合高吸水性树脂的制备、结构与性能

以丙烯酸和高岭土为原料,用反相悬浮聚合法合成了聚丙烯酸钠/高岭土复合高吸水性树脂.研究了加入高岭土的聚丙烯酸钠复合高吸水性树脂合成中反应温度、中和度、交联剂用量、引发剂用量、高岭土添加量等影响树脂吸水性能的主要因素.结果表明,用反相悬浮聚合法合成的复合高吸水性树脂后处理容易,树脂的吸水率达到512 g/g,吸盐水率达到81 g/g,吸水速度比不加高岭土提高20%,保水能力提高15%,在250 ℃加热30 min仍能保持原吸水率的95%.用IR和TEM研究了复合高吸水性树脂的表面和结构,TEM显示高岭土的加入对树脂颗粒大小和形状有较大的影响,IR初步表明聚丙烯酸与高岭土产生了交联.     

水溶液聚合小麦淀粉接枝丙烯酸高吸水性树脂的研究

以小麦淀粉与丙烯酸为原料,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高吸水性复合树脂。考察了丙烯酸的中和度、淀粉/单体比例、引发剂、交联剂等对聚合反应和树脂性能的影响。通过正交试验优选出物料的最佳配比:丙烯酸的中和度为90%,引发剂用量为0.5%,交联剂用量为0.05%,淀粉含量为10%。制备得到的吸水性复合树脂吸水率达1060g.g-1,性能优于聚丙烯酸钠高吸水性树脂。     

GG-g-PAA／SH高吸水性树脂的制备与缓释性能研究

以天然瓜尔胶（GG）、丙烯酸（AA）和腐植酸钠（SH）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,采用水溶液聚合法制备了环境友好的多功能瓜尔胶接枝聚丙烯酸／腐植酸钠（GG-g—PAA／SH）高吸水性树脂。考察了腐植酸钠含量对树脂吸水性能的影响,评价了树脂在沙土中的实际保水性能、反复溶胀性能和腐植酸钠肥料缓释性能。结果表明,在体系中引入廉价的腐植酸钠,不但降低生产成本,还能提高树脂的吸水能力,当腐植酸钠含量为15wt％时,高吸水性树脂吸蒸馏水和生理盐水的倍率分别为532g／g和62g／g。在沙土中加入高吸水性树脂能显著提高其保水性能,30d后仍能保持13％的水分。此外,GG-g-PAA／SH高吸水性树脂还具有较优的反复溶胀性能和腐植酸钠肥料缓释功能,可用作兼具吸水、保水和缓释性能的新型节水材料。     

Synthesis and Characterization of Poly(acrylic acid)/Poly(vinyl alcohol)-xanthan Gum Interpenetrating Network (IPN) Superabsorbent Polymeric Composites

Initially interpenetrating network (IPN) hydrogel was prepared by dispersing xanthan gum (XG) into poly(vinyl alcohol) (PVA) backbone in an aqueous medium. Polyacrylic acid (PAA)/Poly (vinyl alcohol)-Xanthan gum IPN superabsorbent composite were fabricated well by dispersing the prepared IPN hydrogel in acrylic acid and polymerized in a complete aqueous environment through chemical cross-linking method. These superabsorbent polymeric composites were analytically evaluated by scanning electron microscopy (SEM), Fourier Transform Infrared Spectra (FTIR), Thermal analysis (DSC) and X-ray diffraction (XRD) analysis. Simultaneously water absorbency, swelling kinetics and water retention abilities of this prepared superabsorbent polymeric composites were also investigated systematically.     

Degradation of wheat straw/polylactic acid composites with and without sodium alginate in natural soil and the effects on soil microorganisms

In order to improve the degradability of polylactic acid (PLA) composites and screen PLA degradation microorganisms. Sodium alginate was added into the wheat straw/PLA composites, and both composites (with/without sodium alginate) were buried in natural soil for 100 consecutive days subsequently. Weight loss and characterization of the PLA composites, carbon and nitrogen content in soil and microbial community composition were detected after degradation, with the result that the degradability of the PLA composites was greatly improved after the addition of sodium alginate. The weight loss of PLA composites with sodium alginate was 8.5%, which was 1.81 times that of PLA composites without sodium alginate. Sodium alginate and/or wheat straw in the PLA composites took the lead in the beginning course of the degradation. The added sodium alginate serves the purpose of making it easier to degrade the crystallization zone of the PLA composites. Bionectriaceae in the soil shoots up in the number after degradation, signifying its potential to be part of the microorganism family serving to degrade PLA composites. The results would help reveal the degradation mechanism of PLA composites and provide support for the screening of PLA composites degradation microorganisms.     

Frontal polymerization of superabsorbent nanocomposites based on montmorillonite and polyacrylic acid with enhanced soil properties

Polyacrylic acid/montmorillonite(MMT)/carboxymethylcellulose (CMC) superabsorbent nanocomposites were prepared by frontal polymerization (FP), an economic method characterized by low‐energy consumption and short‐reaction time. They were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy, and scanning electron microscopy. The effects of reaction parameters on the front propagation and the water absorbency of the nanocomposites were investigated. Furthermore, the effects of the obtained products on soil water holding capacity and soil water stable macro‐aggregates were studied. Compared with the control soil, soil mixed with the nanocomposites showed a significant increase (by 52.4%) in field water holding capacity. The incorporation small amounts of MMT effectively promoted the formation of soil water stable macro‐aggregates, which increased by 76% as the addition of the MMT increased to 4 wt %. The samples obtained by FP showed much better performance in the formation of soil water stable macro‐aggregates, salt resistance, and thermal stability than those obtained by conventional batch polymerization. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39825.     

烟区土壤残留二氯喹啉酸的消解动态

取受害烟区无用药的pH值为5．84的土样,分别添加二氯喹啉酸0．8mg／kg和11．6mg／kg,采用高效液相分析方法,测得180d内的二氯喹啉酸两种添加量的自然降解情况,经检测分析,当添加量为0．8mg,kg时,所测半衰期为23．30d。当添加量为1．6mg,kg时,所测半衰期为22．04d。180d后仍可以检测到0．069-0．085mg／kg的残留量,所求消解率为89．35％-95．78％。根据二氯喹啉酸在土壤中的消解动态,在稻田施用一次二氯喹啉酸后,种植烟草的安全间隔期为342d。     

Study on superabsorbent composites. XVIII. Preparation,characterization, and property evaluation of poly(acrylic acid‐co‐acrylamide)/organomontmorillonite/sodium humate superabsorbent composites

A series of novel multifunctional poly (acrylic acid‐co‐acrylamide) (PAA‐AM)/organomontmorillonite (O‐MMT)/sodium humate (SH) superabsorbent composites were synthesized by the graft copolymerization reaction of partially neutralized acrylic acid and acrylamide on O‐MMT micropowder and SH with N,N′‐methylene bisacrylamide as a crosslinker and ammonium persulfate as an initiator in an aqueous solution. The superabsorbent composites were characterized by means of Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, and thermogravimetric analysis. The effect of the relative weight ratio of SH to O‐MMT on the water absorbency was studied, and the results indicated that the best water absorbency of 591 g/g in distilled water was obtained when an O‐MMT content of 20 wt % and an SH content of 30 wt % were incorporated. The superabsorbent composite possessed a good capacity for water retention; even after 30 days, 24.4 wt % of water could still be saved by the sand soil containing 1.0 wt % superabsorbent composite. The results from this study show that the water absorbency of a superabsorbent composite is improved by the simultaneous introduction of O‐MMT and SH into a PAA‐AM network in comparison with the incorporation of only O‐MMT or SH. Also, in comparison with PAA‐AM/MMT/SH, an appropriate amount of O‐MMT can benefit the developed composites with respect to their water absorbency, salt resistance, and capacity for water retention in sand soil. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

海藻酸纤维对碱性品红的吸附性能研究

以自制海藻酸纤维为吸附剂,考察了吸附剂用量、溶液温度、吸附时间和溶液pH值等因素对海藻酸纤维吸附碱性品红的吸附效果的影响。结果表明:脱色率随海藻酸纤维加入量的增加而提高,随着溶液温度升高而迅速下降;加酸或加碱都不利于海藻酸纤维对碱性品红的吸附;对于40 mg/L的碱性品红溶液,当海藻酸纤维的加入量为5 g/L,室温下振荡40 min既能达到吸附平衡,脱色率可达96%;Freundlich等温方程能很好地描述海藻酸纤维对碱性品红的吸附,其吸附行为是物理吸附,吸附过程为熵减过程;海藻酸纤维经过8次再生后,对碱性品红的脱色率仍可达到93%以上,可重复利用。     

High‐temperature resistant superabsorbent based on poly(acrylic acid) with triallylammonium chloride as crosslinking agent

A novel high‐temperature resistant superabsorbent was prepared by solution polymerization of partially neutralized acrylic acid (AA), using triallylammonium chloride as crosslinker, potassium persulfate as initiator. The factors that influence the water‐absorbing capacity at 25 and 200°C such as mass concentration of monomer, mass ratio of crosslinker to AA, mass ratio of initiator to AA, and neutralization degree were investigated. The structure of the superabsorbent was characterized by Fourier transform infrared, thermogravimetric analysis, and scanning electron microscopy. The optimum conditions were obtained and the swelling ratios in distilled water and 1 wt % of NaCl solution could reach 841 and 74 g/g at 300°C, respectively. The superabsorbent also showed high swelling rate and good salt resistance. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41243.