【作者】 高坡；

【导师】 方桂珍；

【作者基本信息】 东北林业大学 ， 林产化学加工工程， 2009， 博士

【摘要】 本课题是高等学校博士学科点专项科研基金资助项目(项目编号:20060225008)中的部分内容。本论文利用纤维素具有亲和吸附性,通过化学改性使其成为吸附选择性特殊、吸附能力高且稳定性好的吸附材料。肾病发生可引起内源性化学毒素尿素氮,如尿素、尿酸、肌酐和胆红素等成分的大量积蓄,从而加重病情,引发多种并发症。氧化纤维素上的醛基可与尿素氮上的胺基形成亚胺键而被化学吸附后排出体外。当含有醛基的氧化纤维素主链上连有多胺类基团时,胺基氮原子上的孤对电子可以配位络合大多数重金属离子的核外价电子层可接受孤对电子的空轨道,对其具有很强的配位吸附作用。基于这个原因首次研制出即有吸附尿素氮等小分子毒素的醛基官能团,又有吸附重金属离子毒物的多胺类基团的氧化纤维素多胺化产物。本论文选择可用于口服的微晶纤维素将其氧化成C2、C3位为两个醛基的氧化纤维素YX,然后C6位羟基进行氯化的置换反应生成YX-C1。以此氯原子为活性基团进行二乙烯基三胺(A2.3)、三乙烯基四胺(A3.4)的多胺化反应,生成氧化纤维素的多按化产物,即双功能吸附剂YXA2.3和YXA3.4二种。考察了各影响因素对产物制备的影响;通过FTIR、元素分析和XPS等手段对合成产物的超分子结构、化学结构组成进行表征;对二乙烯基三胺基氧化纤维素(YXA2.3)、三乙烯基四胺基氧化纤维素(YXA3.4)的吸附性能进行了研究。研究结果表明:微晶纤维素活化、氧化后产率平均范围分别为:77.5%～82.5%、81%～85%,氧化纤维素醛基含量为97.61%。氧化纤维素氯化反应时间为2.5 h,DMF用量为20 mL时,产率约为95%。确定多胺化反应的较佳条件:在200mL DMSO搅拌加热至100℃,滴加A2.3和A3.4各10mL,维持温度反应12h,在酸性条件(pH:4-5)下生成,产率大约在46%左右。对YXA2.3进行有机元素分析结果为:C 45.1,H 4.7,N 11.1(理论值为:C 49.0,H 7.8,N 17.1),其中11.1＜17.1,4.7＜7.8,这是由于大分子的特性,氧化纤维素的氯化物只部分发生的胺化。与微晶纤维素中元素比例(理论值C 44.0%:H 6.2%)相比较,氢的比例:4.7＜6.2,并还小于氧化纤维素的胺化产物中的氢值,说明是2,3位为醛基的氧化纤维素的胺化产物。光电子能谱分析结果可以确认有四种不同价键结构类型C-C,C-O和C-N,以及C=O,表明得到了预期结构的纤维素修饰产物。红外光谱也证实了胺化结果。二乙烯基三胺基氧化纤维素的吸附性能结果表明:(1)吸附温度为37℃,pH=7时,0.5g吸附剂对于尿素(6g/L)、尿酸(1g/L)、肌酐(0.1g/L)5 h的静态吸附容量分别为122.0mg/g、19.8mg/g、3.04mg/g。1-10h吸附平衡时间都为8h,吸附平衡容量分别为123.9 mg/g、19.8mg/g、3.32 mg/g;(2)砷(Ⅲ)的静态吸附结果:0.5g吸附剂对砷(Ⅲ)浓度分别为0.2ppm,2.0ppm,20.0ppm的二次水溶液中进行吸附,分别在5h的时间取样,其吸附容量分别为3.4μg/g、78.8μg/g和403.5μg/g。砷(Ⅲ)浓度分别与(2)浓度相同的透析液中,分别在5h的时间取样,其吸附容量分别为8.91μg/g、8.4μg/g和415.0μg/g。(3)对砷(Ⅲ)的动态吸附结果:0.5g YXA2.3在透析液中砷(Ⅲ)浓度分别为0.2ppm、2.0ppm和20.0ppm时,分别做1-11h、1-8h和1-8 h动态吸附实验,吸附平衡分别在8h、6h和7h时基本达到,平衡时吸附容量分别为5.81μg/g、67.3μg/g和411.0μg/g。在二水溶液中,分别做1-8h、1-8h和1-11h动态吸附实验,吸附平衡分别在6h、6h和7h时基本达到,平衡时吸附容量分别为5.85μg/g、78.3μg/g和403.2μg/g。吸附动力学实验结果表明,由于相同的吸附体积,随着吸附质砷(Ⅲ)浓度的增加,吸附容量曲线均是呈线性增加。三乙烯基四胺基氧化纤维素的吸附性能结果表明:(1)吸附温度为37℃,pH值为7时,0.5g吸附剂对于尿素(6g/L透析液)、尿酸(1g/L二次水)、肌酐(0.1g/L透析液)在5h的静态吸附容量分别为131.5mg/g、24.6mg/g、3.31mg/g。(2)0.5g吸附剂对尿素、尿酸、肌酐在0-9h内的吸附,平衡吸附时间均为6h,平衡吸附容量分别为133.2 mg/g、24.9 mg/g、3.42mg/g。(3)吸附剂YX3.4对砷(Ⅲ)的静态吸附结论为:当砷(Ⅲ)浓度分别为0.2ppm,2.0ppm,20.0ppm的二次水溶液中,0.5g吸附剂分别在6h时取样,其吸附容量为:5.56μg/g、60.46μg/g和436.71μg/g。(4)吸附剂YX3,4对砷(Ⅲ)的动态吸附结论;当砷(Ⅲ)浓度分别为0.2ppm,2.0ppm,20.0ppm的二次水溶液中,分别在0.5g吸附剂存在下,5h时当达到吸附平衡,平衡吸附容量分别为5.33μg/g、59.03μg/g、430.19μg/g;随砷(Ⅲ)的二次水中浓度增加而呈线性增加趋势。(5)吸附剂YX3.4对铬(Ⅵ)的动态吸附结论为:当吸附剂质量为0.25、0.5、0.75g,铬(Ⅵ)浓度为2.0ppm二次水液中,在37℃,分别做1-7h动态吸附实验,对铬(Ⅵ)的吸附在6h时基本达到吸附平衡,平衡时吸附容量分别为121.1μg/g、70.2μg/g、41.0μg/g。吸附容量呈下降趋势。综上所述,合成产物能够有效的吸附尿素氮,静态吸附和动态吸附都能达到一定的指标。而多胺基也能有效的对不同吸附环境,不同浓度的砷(Ⅲ)和铬(Ⅵ)产生有效吸附,其静态吸附、动态吸附和吸附动力学的指标与同类相关衍生物的吸附结果相似。可望为制备具有吸附性能的新型功能高分子奠定基础。更多还原

【Abstract】 This dissertation is supported by the Specialized Research Fund for the Doctoral Program of Higher Education(No.20060225008).In this research we converted cellulose by chemical modification into some materials with high selective adsorbability and good stability.Kidney illness can cause substantial savings of endogenous chemical toxins such as urea nitrogen,uric acid, creatinine and bilirubin,thereby increasing the patient’s condition to trigger a variety of complications.The oxycellulose can eliminate these toxins from bodies by chemical adsorption that their aldehyde groups can react with amino groups of urea nitrogen to form imines.Amino groups with lone electron pairs on their nitrogen atoms can complex with most heavy metal ions with empty electronic orbits in their valences shell,so we attached amines to oxycellulose to develop a new polyamine-modified oxycellulose in which small molecule toxins like urea nitrogen could be adsorbed onto aldehyde group and heavy metal ions could be adsorbed onto poly amino group at the same time.We prepared dual functional adsorbents YXA2.3 and YXA3.4 by reactions of diethylene triamine(A2.3) and triethylene tetraamine(A3.4) with YX-Cl as a product from the chlorination of the hydroxy at C6 of YX which was synthesized by oxidating C2,C3 of oral microcrystalline cellulose to aldehyde groups.Meanwhile,the influence factors on the reaction process were investigated.The supermolecular structures and chemical structures of polyamine-modified oxycellulose were characterized by FTIR,elemental analysis and XPS.Their adsorption properties were studied.The results indicated that the yields activating and oxidating microcrystalline cellulose were in the range of 77.5%～82.5%,81%～85%respectively,the aldehyde content in oxycellulose was 97.61%.When oxycellulose was chlorinated in 20mL DMF for 2hs,the yield was about 95%.The appropriate conditions of polyaminating reaction was that oxycellulose chloride in 200mL DMSO was heated to 100℃with stirring,then was dropwised 10mL A2.3 and A3.4 separately,remaining the temperature for 12h,after pH was justed to 4-5,the products were obtained in 46%yield.Compared with theoretical values 49.0%C,7.8%H,17.1%N the elemental analysis results of YXA2.3 that was 45.1%C,4.7%H and 11.1%N showed that oxycellulose chloride were aminated only partially in about 45%yield because of their huge molecular volume.Photoelectron spectroscopy analysis demonstrated that there were four different bond species such as C-C,C-O and C-N,and C = O in products,which shows that the expected modified structure have been received.The infrared spectra also confirmed the results.The adsorption experiments of diethylene triamine-modified oxycellulose showed that:(1) The static adsorbing capacities of 0.5g adsorbent for urea(6g/L),uric acid(1g/L) and creatinine(0.1g/L), were 122.0mg/g,19.8mg/g,3.04mg/g respectively at 37℃and pH7 in 5h.when three adsorption equilibriums were reached after 8h the corresponding adsorption capacities were 123.9 mg/g, 19.8mg/g,3.32 mg/g.(2) When 0.5g adsorbent was treated with solutions of Arsenic(Ш) in redistilled water at the concentrations of 0.2ppm,2.0ppm and 20.0ppm the adsorption equilibriums were reached separately after 7h,6h and 11h,the corresponding adsorption capacities were 3.4μg/g, 78.8μg/g and 403.5μg/g.When the dialysis solution of Arsenic(Ш) at the same concentration was tested,the adsorption equilibriums were reached after 11h,6h and 8 h respectively so that adsorption capacities were 8.9μg/g,8.4μg/g and 415.0μg/g correspondingly.(3) When 0.5g adsorbent YXA2, 3 was treated separately with dialysis solutions of Arsenic(Ш) at the concentrations of 0.2ppm, 2.0ppm and 20.0ppm during 1-11h,1-8h and 1-8h,the dynamic adsorption equilibriums were reached separately after 8h,6h and 7h,the corresponding dynamic adsorption capacities were 5.81μg/g,67.3μg/g and 411.0μg/g.While redistilled water was substituted for dialysis solutions the dynamic adsorption experiments respectively carded for 1-8h,1-8h and 1-11h and the adsorption equilibriums were reached separately after 6h,6h and 7h,the corresponding dynamic adsorption capacities were 5.85μg/g,78.3μg/g and 403.2μg/g.The experimental results of absorption kinetics of indicated that at the same adsorption volume the adsorption capacity curve was linear with increasing the arsenic(Ⅲ) concentration.The adsorption results of triethylene tetraamine-modified oxycellulose showed that:(1) when adsorption tests were carried at 37℃and pH7 in 5 h,static adsorption capacity of 0.5g adsorbent for urea(6g/L in dialysis solution),uric acid(1 g/L in redistilled water) and creatinine(0.1 g/L in dialysis solution) were 131.5mg/g,24.6mg/g,3.31mg/g respectively.(2) when 0.5g adsorbent was treated with urea,uric acid and creatinine for 9h three adsorption equilibriums were all reached after 6h and the corresponding adsorption capacities were 133.2 mg/g,24.9 mg/g,3.42mg/g.(3) The static absorptions of adsorbent YX3,4 for arsenic(Ш) was that the adsorption equilibriums were all reached after 6h when 0.5g adsorbent YX3,4 was treated with solutions of Arsenic(Ш) in redistilled water at the concentrations of 0.2ppm,2.0ppm and 20.0ppm,the corresponding adsorption capacities were 5.56μg/g,60.46μg/g and 436.71μg/g.(4) The dynamic absorptions of adsorbent YX3,4 for arsenic(Ш) gave a conclusion that when arsenic(Ш) concentrations were 0.2ppm,2.0ppm,20.0ppm in redistilled water the all adsorption equilibriums were reached after 5h in the presence of 0.5g adsorbent and equilibrium adsorption capacities were 5.33μg/g,59.03μg/g, 430.19μg/g respectively.The adsorption capacity increased linearly with increase of arsenic(Ш) concentration.(5) When 0.25g,0.5g and 0.75 g of adsorbent YX3,4 were treated with Cr(Ⅵ) in redistilled water at the concentration of 2.0ppm at 37℃for 1-7h,all dynamic absorption equilibriums were reached nearly after 6h and corresponding equilibrium adsorption capacities are 121.1μg/g,70.2μg/g and 41.0μg/g,which gave a decreasing tendency. In summary,the products can adsorb urea effectively in both static and dynamic absorption. And poly amino group also can absorb arsenic(Ⅲ) and Cr(Ⅵ) at different concentrations effectively under various environments.Since the performances in static adsorption,dynamic adsorption and adsorption kinetics are similar to related derivatives,these products have the potential to become new functional macromolecular materials.更多还原