节点文献

羽毛蛋白基高吸水性树脂的制备与性能研究

Study on Preparation and Peoperties of Feather Protein-based Superabsorbents

【作者】 尹国强

【导师】 崔英德;

【作者基本信息】 西北工业大学 , 材料学, 2006, 博士

【摘要】 在总结国内外高吸水性树脂研究、生产和应用的现状后,提出从改善树脂生物降解性、耐盐性和废弃资源综合利用的角度出发,以羽毛粉、羽毛杆等羽毛角蛋白为原料,经水解和化学改性制备可溶性羽毛蛋白质,再与丙烯酸类单体接枝共聚合成羽毛蛋白基高吸水性树脂的新工艺。探讨了羽毛蛋白基高吸水性树脂制备工艺条件对树脂性能影响。研究了羽毛蛋白基高吸水性树脂的吸水保水性能、耐盐性能、生物降解性能、对重金属离子的吸附性能及其结构。并对高吸水性树脂对土壤理化性能的影响及生物学效应进行了初步探讨。通过亚硫酸氢钠预处理,采用氢氧化钠溶液水解羽毛粉成功制备了水溶性羽毛蛋白(FP)。制备的最佳工艺条件为:亚硫酸氢钠的用量w(亚硫酸氢钠):w(羽毛粉)为30:100、氢氧化钠浓度为0.4%、液固比15:1、反应温度90℃、反应时间2 h。在此条件下,可溶性羽毛蛋白的收率达65.7%,分子量大部分在10000~40000之间,较适合用于接枝聚合反应。利用甲醛和亚硫酸氢钠对FP进行亲水性改性,在羽毛蛋白分子中引入强亲水的磺酸基和羟基,制备出改性羽毛蛋白质(MFP)。利用戊二醛作交联剂,制备出FP吸水凝胶和MFP吸水凝胶,实验证明,MFP吸水凝胶比FP吸水凝胶吸水倍率明显提高,由21.5g/g提高到45.6g/g。FTIR红外光谱分析表明共聚树脂中丙烯酸与羽毛蛋白发生了接枝共聚反应。以MFP和丙烯酸为主要原料,N,N’—亚甲基双丙烯酰胺为交联剂,采用过硫酸钾-亚硫酸氢钠氧化-还原引发剂溶液聚合法合成了羽毛蛋白接枝聚丙烯酸高吸水性树脂[P(MFP-g-AA)]。详细研究了影响合成树脂的吸水性能和单体转化率的各种因素,确定适宜的反应条件为:wMFP:wAA=10%、w交联剂:wAA=0.12%、w引发剂:wAA=0.6%、丙烯酸中和度90%、反应温度60℃、反应时间2h。在此条件下合成的P(MFP-g-AA)树脂在去离子水中的吸水倍率达到559.4g/g。研究表明:P(MFP-g-AA)树脂比纯PAA具有优良的耐盐性能、保水性能和更宽的pH值适用范围,在0.9%NaCl溶液和人工尿液中的吸水倍率分别由56.9 g/g和51.8 g/g提高到68.7g/g和61.3g/g,并且在pH=7-11的介质中都有优良的吸水效果,凝胶在0.3MPa的压力下保水率为85%。为了提高树脂中非离子基团比例,在聚合单体体系中增加了丙烯酰胺制备出羽毛蛋白接枝丙烯酸-丙烯酰胺高吸水性树脂P(MFP-g-AA/AM)。适宜工艺条件为:单体中丙烯酸和丙烯酰胺配比为wAA:wAM=70:30,丙烯酸中和度为90%,MFP的用量为wMFP:w单体=10%,引发剂用量为w引发剂:w单体=0.8%,交联剂用量为w交联剂:w单体=0.10%,反应温度60℃,反应时间2h。由于AM的协同效应,合成的P(MFP-g-AA/AM)树脂比P(MFP-g-AA)树脂吸水保水性能和耐盐性能都要好,在去离子水、0.9%NaCl溶液和人工尿液中的吸水倍率分别由559.4g/g、68.7g/g和61.3g/g提高到578.0g/g、78.6g/g和75.1g/g,凝胶在0.3MPa的压力下保水率为86.1%。利用FTIR红外光谱分析表明共聚树脂中丙烯酸和丙烯酰胺与羽毛蛋白发生了接枝共聚反应,并用SEM分析了聚合树脂的形貌特征。研究了所制备的高吸水性树脂对重金属离子吸附性能。结果表明,树脂对铅、铜等重金属离子具有很好的吸附性能,吸附容量都在2.2mmol/g以上,重金属离子的脱除率可高达95.7%;尤其是P(MFP-g-AA/AM)树脂磺甲基化改性后,因含有-COO-和-SO3-两种阴离子,效果更加明显,对铅离子的吸附容量可高达2.5mmol/g。因此,羽毛蛋白基高吸水性树脂可用于含重金属离子的污水处理和重金属离子的富积、分离和提纯。在聚合单体体系中引入少量烯丙基结构的长链季铵盐(RADM)单体,制备出具有抗菌杀菌性能高吸水性树脂。树脂凝胶对大肠杆菌、金黄色葡萄球菌和白色念珠菌等均有较好的杀灭和抑制其生长的作用;树脂中季铵盐含量越高、季铵基团中烷基链越长,抗菌性能越强;树脂凝胶与含菌液接触8h,抗菌率都在75%以上。适用于作医疗卫生用高吸水性树脂。采用微生物分解法,研究了羽毛蛋白基高吸水性树脂的生物降解性能。结果证明,树脂能被霉菌、放线菌和枯草杆菌等微生物降解,其中P(MFP-g-AA)树脂的生物降解性能最好,其凝胶薄片在含霉菌的溶液中放置45天,凝胶表面基本被霉菌覆盖;含有抗菌性长链季铵基团的树脂,可控制树脂的生物降解速度,这对于在实际生产中制备使用寿命可控型的高吸水性树脂具有十分重要意义。采用环氧氯丙烷和三氯化铝等交联剂、乙醇为分散剂,对树脂颗粒进行表面改性,制备出类似“核壳”结构的高吸水性树脂。实验表明,树脂改性后颗粒松散,防潮性、流动性增加,吸液速率提高。表面改性后的PAA树脂和P(MFP-g-AA/AM)树脂的吸液速率分别由93s和112s提高到35s和54s。研究了羽毛蛋白基高吸水性树脂对土壤理化性能的影响及生物学效应。研究证明,高吸水性树脂可降低赤红土壤中水分的蒸发速度,改善土壤通透性,降低土壤日照温度差,促进土壤团粒结构的形成,特别对0.5~4mm粒径的团粒的形成影响显著。树脂拌土面施实验证明,P(MFP-g-AA/AM)树脂能显著提高不同类型种子的出苗率,在5mm/d降水量模拟条件下,使用拌土面施的小麦出苗率是对照的14倍。胁迫干旱实验表明,使用高吸水性树脂能明显延长作物的耐旱生存期,施用一定量的P(MFP-g-AA/AM)树脂,可比对照生存期延长10—35天。

【Abstract】 In this paper, superabsorbents were synthesized by graft of acrylic acid onmodified feather protein. The influence of reaction conditions on the properties of thesuperabsorbents were studied, anti-salt property, biodegradability and adsorptiveproperty on heavy metal ion were studied as well.Soluble feather protein was prepared by pre-treatment of feather protein powderwith NaHSO3 then hydrolyzation in solution containing NaOH. The results showedwhen the dosage of NaHSO3 was 30wt% of the feather protein, the concentration ofthe solution containing NaOH was 0.4wt%, the proportion of the solution and thefeather protein was 15, the reaction continued at 90℃for 2 hours, 65.7% featherprotein could transform into water soluble protein and the molecular weight wasbetween 10000~40000, suitable for graft of acrylic acid. Modified feather proteinswith improved hydrophilicity were synthesized by formaldehyde and NaHSO3. thehydrogels of the feather protein and modified feather protein were synthesizedseparately with glutaraldehyde being used as crosslinker, the results showed that theabsorbing ability of the hydrogels of the modified feather protein (45.6g/g) wasmore than that of the hydrogels of the feather protein (21.5g/g).Superabsorbents of modified feather protein grafted acrylic acid were synthesizedby polymerization of modified feather protein and acrylic acid in water when N, N’-methylenebisacrylamide (NMBA) being used as crosslinker and K2S2O8-NaHSO3 beingused as initiator. When the dosage of modified feather protein was 10wt% of acrylicacid, the dosage of NMBA was 0.12wt% of acrylic acid, the dosage of initiator was0.6wt% of acrylic acid, 90% acrylic acid was neutralized by NaOH, and the reactioncontinued at 60℃for 2 hours, the absorbing ability of the superabsorbents was 559.4g/g in case of distilled water, 68.7g/g in case of physiological saline, 85% water inthe superabsorbents was held under the pressure of 0.3MPa, while the absorbingability of the superabsorbents of crosslinked acrylic acid was 56.9g/g in case ofphysiological saline.Superabsorbents of modified feather protein grafted acrylic acid and acrylamidewere synthesized by polymerization of modified feather protein and acrylicacid/acrylamide in water when NMBA was being used as crosslinker and K2S2O8-NaHSO3 being used as initiator. When the dosage of modified feather proteinwas 10wt% of acrylic acid and acrylamide, the proportion of acrylic acid andacrylamide was 70: 30, the dosage of NMBA was 0.10wt% of acrylic acid andacrylamide, the dosage of initiator was 0.8wt% of acrylic acid and acrylamide, 90%acrylic acid was neutralized by NaOH, and the reaction continued at 60℃for 2 hours,the absorbing ability of the super absorbents was 578.0g/g in case of distilled water,78.6g/g in case of physiological saline, 85% water in the super absorbents was heldunder the pressure of 0.3MPa.Adsorptive property of the superabsorbents on heavy metal ion were studied inthis paper, the results showed that Pb2+, Cu2+ can be absorbed by the superabsorbents,and the adsorptive capacity was bigger than 2.2mmol/g, 95.7% heavy metal ion canbe absorbed.Superabsorbents with anti-bacteria activity was synthesized by modified featherprotein grafted acrylic acid, acrylamide and long-chain alkyl allyl dimethylammonium chloride (RADM), and the results showed Staphylococcus aureus,Escherichia coli and Candida albicans can be killed or controlled. When the contentof RADM increased, anti-bacteria activity increased.Biodegradability of the superabsorbents based on modified feather protein andacrylic acid/acrylamide was studied by microbe, and the results showed that the superabsorbents could be degrade by Mould fungi, Actinomyces, Bacillus subtilis. Thesuperabsorbents of modified feather protein and acrylic acid had the best degradability,the hydrogel of the superabsorbents was covered by fungus when contact with thesolution containing Mould fungi.The superabsorbents were modified in particle surface while epoxychloropropane and AlCl3 being used as crosslinker and ethanol being used asdispersing agent, the results showed that the humidity resistance could be improved,and the absorption rate could be improved from 112 s to 54 s.Influence of the superabsorbents based on modified feather protein and acrylicacid/acrylamide on wheat seeding and properties of soil were studied, and the resultsshowed the evaporation rate of soil could be reduced, difference in temperature of soilbetween day and night could be reduced as well. The coming out ratio of wheat is 14times for soil containing the superabsorbents than that of blank.

节点文献中: