聚丙烯酸钠高吸水树脂合成及尿素控释性研究

利用新型交联剂制备了聚丙烯酸钠高吸水性树脂,研究考察了交联剂种类及用量、引发剂用量、丙烯酸中和度以及反应时间等因素对高吸水性树脂溶胀率及溶解率的影响,得到了制备高溶胀率、低溶解率产物的最佳反应条件:交联剂用量0.08%(占丙烯酸单体的质量分数,下同),引发剂用量0.10%,丙烯酸的中和度60%,反应时间10 h.同时利用高吸水性树脂凝胶作为尿素控制释放基质,考察了高吸水树脂交联度、中和度等因素对尿素控制释放速率的影响.     

固定化植物酯酶-显色剂传感膜的制备与性能

采用聚乙烯醇(PVA)与四乙氧基硅烷(TEOS)通过原位溶胶-凝胶法制备了PVA/SiO2有机/无机杂化溶胶,并将显色剂和植物酯酶分散于溶胶中,干燥成膜,得到一类透明度高、亲水-亲丙酮性可调、贮存性好的传感膜.该传感膜在乙酸-α-萘酯溶液中,会于可见光520 nm处出现一个新的吸收峰.传感膜在制备后的12天内活性明显下降,之后基本保持稳定,并且冷藏活性下降率要比室温保存的小很多.但不论是冷藏还是在室温下保存,被固定在杂化膜中的酶活稳定性都比在溶液状态下的明显提高.     

Electro-spinning Antimicrobial N-halamine Modified Poly （vinyl alcohol） Nanofibers

Antimicrobial poly( vinyl alcohol)( PVA) nanofibrous composites were prepared by adding 3-( 2,3-dihydroxypropyl)-5,5-dimethylimidazolidine-2,4-dione( N-halamine diol) to the PVA solution using electro-spinning technique upon curing and exposure to diluted sodium hypochlorite. Scanning electron microscopy( SEM) demonstrates that PVA nanofibers formed with diameters of( 255 ±94) nm. Cross-linked PVA nanofibers with N-halamine diol precursor and 1,2,3,4-butanetetracarboxylic( BTCA) showed good water resistance. The chlorinated PVA nanofibrous mats completely inactivated Staphylococcus aureus( Gram-positive) and Escherichia coli O157: H7( Gram-negative) with 7 log reductions( the reduction of the bacterial concentration in logarithm) within 5min and 1 min of contact time,respectively.     

含有氨基酸基团的聚(ε-己内酯)合成与表征

采用氨基酸钠游离的氨基引发ε-己内酯单体开环得到酯肽齐聚物,并以六亚甲基二异氰酸酯为扩链剂,将这些齐聚物扩链合成4种聚酯酰胺.将4种天然氨基酸(L-丙氨酸、L-亮氨酸、L-谷氨酸、L-赖氨酸)引入到聚(ε-己内酯)(poly(ε-caprolactone),PCL)中,合成和表征了4种含有氨基酸残基的聚合物.通过1H-NMR、FT-IR、水接触角、水吸收率和降解实验对该聚酯酰胺进行了表征.实验结果表明:经氨基酸改性PCL的亲水性和降解性得到了改善,其中含有L-赖氨酸残基的聚酯酰胺因亲水性最高,降解速率最快.     

A positive-temperature-coefficient electrode with thermal protection mechanism for rechargeable lithium batteries

A new positive-temperature-coefficient(PTC) material was prepared simply by blending of conductive Super P carbon black(CB) with insulating poly(methyl methacrylate)(PMMA) polymer matrix,which was empolyed as a coating layer on the aluminium foil substrate to fabricate a sandwiched Al/PTC/LiCoO2 cathode.The experimental results from cyclic voltammetry,charge-discharge measurements and impedance spectroscopy demonstrated that the PTC electrode has a normal electrochemical performance at ambient temperature,but shows an enormous increase in the resistance at the temperature range of 80?120℃.This PTC behavior greatly restrains the reaction current passing through the electrode at elevated temperatures,capable of acting as a self-actuating safety mechanism to prevent the battery from thermal runaway.     

Fluorinated Hyperbranched Poly（urea-urethane）s Containing Reactive Groups： Synthesis, Characterization and Application on Cotton Fabric

A series of hyperbranched poly(urea-urethane) s (HPUs)containing short fluoroalkyl chain and reactive groups (HPUFs)capable as hydrophobic and oleophobic coating materials were synthesized.The obtained polymers were characterized by FTIR ( fouier transform-infrared spectroscopy ),1 H NMR ( nuclear magnetic resonance),13C NMR,19F NMR,GPC(gel permeation chromatography),TGA ( thermogravimetric analyzer),and XPS (X-ray photoelectron spectroscopy) analyses.Highly hydrophobic and oleophobic cotton fabrics could be achieved from these fluorinated hyperbranched polymers by solution-immersion coating method.The static contact angles reached to 143°,114°,and 92° for water,hexadecane,and decane,respectively.The water and oil repellency ratings were 90 and 6,respectively,and still kept 80 and 5.respectively,after 10 soaping cycles at 50℃.     

药用辅料——高分子聚合材料测定方法的正交试验

设计正交试验,建立药用辅料——高分子聚合材料测定方法.以L9(34)正交试验考查该方法的4个重要因素及水平.确立方法后按2010年中国药典要求做方法学研究.结果表明:该法检测的线性范围为2～100μg.mL-1;r=0.999 8;检出限为0.5μg.mL-1;该方法的平均回收率为0.96;日内RSD为0.02.该方法符合2010年中国药典关于杂质限量检测方法的规定,是检测此类PLLA辅料中乳酸含量的可行方法.     

环氧端基聚丙烯酸正丁酯的光聚合反应机理

研究了以N.N-二(2,3环氧丙基)苯胺(DEA)-二苯甲酮(BP)或DEA-4-(2,3环氧丙氧基)二苯甲酮(EBP)为引发体系的丙烯酸正丁酯的光聚合动力学。提出了DEA-BP引发体系的丙烯酸正丁酯的聚合反应速率方程式。研究表明,DEA分子连结于大分子链的末端,DEA-EBP体系的光聚合引发速率较DEA-BP体系为快。