砷的测定

1　前言二乙胺硫代甲酸银比色法近年来 ,获得较快进展的二乙胺硫代甲酸银(简称 Ag- DDTC)比色法测定砷 ,应用于矿石、水、尿及猪中 ,砷的测定。本方法的优点是灵敏度、准确度高 ,干扰元素少 ,操作手续简便。方法基于在酸性介质中 ,用氯化亚锡与碘化钾将正砷酸还原为亚砷酸 ,然后用金属锌将亚砷酸还原为砷化氢气体 :H3 ASO3 + 3Zn + 6 H =ASH3 ↑ + 3Zn + 3H2 O逸出的砷化氢气体用含有少量有机碱的 Ag-DDTC三氯甲烷溶液吸收 :ASH3 +6 Ag -DDTC =6 Ag +3H DDTC +AS( DDTC) 3此时 ,析出棕红色的胶态银 ,在波长 5 3 0毫微米处…     

含氟核壳纳米粒子的制备及其表征

通过半连续的加料工艺制备了聚甲基丙烯酸三氟乙酯（PTFEMA）为壳,以聚丙烯酸甲酯（PMA）为核的纳米核壳乳液。并通过SEM、TEM、DSC、DLS等对合成的乳液进行表征,结果表明：所合成的粒子具有核壳结构,粒子形貌较为规整,且成球效果很好。     

含氟聚氨酯树脂的制备及性能研究

制备了具有优异拒水、拒油和易去污功能的含氟聚氨酯树脂。方法:通过自制的含氟烷基侧链的含氟二元醇扩链剂(PFDOL)、聚四氢呋喃(PTMEG)、二羟甲基丙酸(DMPA)和二苯基甲烷二异氰酸酯(MD I)等原料,采用两步法制备了含氟聚氨酯树脂。结果:采用傅里叶变换衰减全反射红外光谱(ATR-FTIR)和核磁共振氢谱(1H-NMR)表征了产物的结构。经产物处理后的棉布和皮革对水的静态接触角可以分别达到145°和128°。处理后皮革的拒水性可达10级,拒油性可达8级。同时研究了PFDOL和DMPA含量对产品拒水、拒油和易去污性能的影响,发现DMPA含量为9.73%时,样品仍具有优异的拒水、拒油性能,为制备阴离子型水性含氟聚氨酯提供了基础;DMPA含量为7.2%,F含量为19.2%时,样品具有较好的易去污性能。制备的含氟聚氨酯树脂可应用于纺织品的拒水、柜油整理和易去污整理,具备工业化生产的可能。     

Preparation and Application of Fluorinated Cationic Surfactants

Four fluorinated cationic surfactants were prepared by condensing 2,2,3,3, tetrafluoro-1-propyl chloroacetate with stoichiometric amounts of pyridine, 2-hydroxypyridine, 8-hydroxyquinoline and 8-hydroxyquinaldine to produce four quaternary ammonium salts. The surface and biocidal properties of these surfactants were investigated. Surface properties of their solutions including surface tension, critical micelle concentration (CMC), effectiveness (Π_cmc), maximum surface excess (Γ_max) and minimum surface area (A _min) were investigated with respect to different concentrations at 25 °C. Standard free energies of micellization and adsorption of the prepared surfactants in the aqueous solution were studied. The biocidal activity was determined via the inhibition zone diameter of prepared compounds which tested against six strains as a representative group of microorganisms.

Synthesis and Some Properties of Fluorinated Cationic Surfactants

Three fluorinated cationic surfactants were prepared by condensing N-methyl diethanol amine pentafluoro benzoate with stoichiometric amounts of octyl, dodecyl or hexadecyl bromide. The surface properties and parameters were investigated to find the relationship between the structures of the hydrophobic portion of such compounds. The properties studied include surface tension, critical micelle concentration (CMC), effectiveness (Π_cmc), maximum surface excess (Γ_max) and minimum surface area (A_min) were investigated with respect to different concentrations at 25 °C. Standard free energies of micellization and adsorption of the prepared surfactants in the aqueous solution were studied. The values of Γ_max, standard free energies of micellization \Updelta \textG_\textmic^\texto \Updelta {\text{G}}_{\text{mic}}^{\text{o}} and adsorption \Updelta \textG_\textads^\texto \Updelta {\text{G}}_{\text{ads}}^{\text{o}} were found to increase with the chain length, while the cmc and minimum surface area occupied by one molecule A_min were found to decrease. The biocidal activity was determined through the inhibition zone diameter of prepared compounds which were measured against five strains of a representative group of microorganisms.     

阳离子氟代聚丙烯酸酯乳液的制备及应用

以(NH4)2S2O8作引发剂,阳、非离子表面活性剂作乳化剂,将甲基丙烯酸十二氟庚酯(RfAA)、丙烯酸丁酯(BA)、甲基丙烯酸二甲氨乙酯(DM)以及丙烯酸羟丙酯(HPAA)进行乳液聚合,制得了一种稳定的阳离子氟代聚丙烯酸酯乳液(PCFBA)。用红外光谱(IR)、核磁共振氢谱(1HNMR)对PCFBA主组分的结构进行了表征。用扫描电镜SEM、接触角测量仪、电脑测控柔软度仪等研究了PCFBA在棉纤维织物表面的成膜性及应用性能。结果表明,PCFBA可在纤维表面形成相对均匀的疏水膜,该膜附着在纤维表面,能使整理后棉织物与水的接触角达到134.5°、静态吸水时间超过6 h;当PCFBA用量从0.3 g/100 mL H2O增大到1 g/100 mL H2O时,水在其整理的棉纤维织物表面的接触角从128.2°增大到134.5°,而棉织物的白度则由85.44°略降至84.40°。     

UV固化水性含氟聚氨酯的制备及其性能研究

选用异佛尔酮二异氰酸酯（IPDI）、聚酯多元醇（PCDL）、二羟甲基丙酸（DMPA）、甲基丙烯 酸羟乙酯（HEMA）、季戊四醇三丙烯酸酯（PETA）、三乙胺（TEA）、甲基丙烯酸十二氟庚酯（DFHMA）为 主要原料合成了一种UV固化水性含氟聚氨酯。采用FT-IR、1H NMR、光学接触角测量仪、粒度分析 仪、热重分析仪、电子拉力机等对涂膜的结构与性能进行了表征与测试。结果表明:随着甲基丙烯酸 十二氟庚酯的加入,乳液粒径变大,分布变宽,涂膜接触角明显变大,吸水率明显降低,热稳定性有所 提升,拉伸强度变大。当甲基丙烯酸十二氟庚酯添加量为6%时,涂膜综合性能最好。     

核壳型含氟反应性微凝胶的制备

用乳液聚合方法制备了核壳型含氟反应性微凝胶,讨论了引发剂、乳化剂种类及操作方法对微凝胶稳定性和形貌的影响.     

Fluorinated polypropylene barrier materials: Preparation and characterization

A series of novel fluorinated polypropylenes (FPP) with low surface tension were prepared by reactive extrusion of polypropylene (PP) with fluorinated methacrylate, 2,3,4,5,5,5‐hexafluoro‐2,4‐bis (trifluoromethyl) pentyl methacrylate (HFPMA), aiming at improving the barrier properties of the material for the containers of organic liquids. The surface characteristics of these polypropylene materials and the influence of HFPMA on the crystalline behavior were investigated by the X‐ray photoelectron spectroscopy (XPS) and wide‐angle X‐ray diffraction (WAXD). The surface tension of the FPPs is found to be in the range of 28.8–22.9 mN/m while varying the fluorinated monomer contents, which was lower than that of the original PP (about 30 mN/m). The barrier properties of these materials as the containers were studied by using blow‐molded bottles made of FPP and PP. The results showed that enhanced permeation resistance for acetone and xylene solvents as well as better antiultraviolet transmittance properties were achieved in FPP bottles. The acetone and xylene permeation ratio of the FPP bottles were about 1.62 and 1.28 times compared to that of PP bottles, respectively. In addition, the WAXD and DSC studies suggested that the grafting of the fluorinated methacrylate, HFPMA, onto the PP might induce the formation of β form crystals, which is rarely found in the common PP materials. The percentage of β form crystals reached 33.6%, estimated by WAXD, in the FPP with 20% (by weight) of HFPMA. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

氟化CPE的制备及其在PVC中的应用

通过直接对氯化聚乙烯(CPE)颗粒进行表面氟化,制得氟化氯化聚乙烯,最佳氟化条件为氟气流量10mL/min(对应540gCPE粒料),通氟时间2h。氟化改性CPE用于改性PVC混合料,可提高混合料力学性能、加工性和耐候性,效果优于CPE。     

环保型氟素脱模剂的制备及其应用

以全氟聚醚(PFPE)、全氟己基乙基甲基丙烯酸酯(C_6SFMA)、丙烯酸十八酯(SA)和聚乙二醇甲基丙烯酸磷酸酯(PPME-MMA)为主要原料,以三丙二醇(TPG)为溶剂,以十二烷基硫酸钠(SDS)和脂肪醇聚氧乙烯醚(MOA-20)为乳化剂,采用乳液聚合法制备环保型氟素脱模剂,并以甲基乙烯基硅橡胶硫化成型为例,研究氟素脱模剂的脱模性能。结果表明:氟素脱模剂的脱模性能与膜的摩擦因数有关,PFPE牌号选择DEMNUM S-20(相对分子质量较小),PFPE/含氟丙烯酸酯聚合物(PFA)质量比为40/60,PFA中C_6SFMA/SA/PPME-MMA质量比为60/38/2时,制备的氟素脱模剂脱模力小和脱模持久性好;当TPG和SDS+MOA-20质量分别约占脱模剂(乳液)质量的18%和12.5%、高压均质乳化压力和乳化次数分别为50 MPa和4时,制备的氟素脱模剂具有较好的稳定性。     

水性UV固化含氟丙烯酸酯涂料的制备及性能研究

以甲基丙烯酸十三氟辛酯、甲基丙烯酸、甲基丙烯酸羟乙酯、丙烯酸丁酯和2,4-甲苯二异氰酸酯为原料,通过三步反应合成了一种新型的水性可光固化含氟丙烯酸酯树脂.利用FT-IR、PCS、TG、TGA等分析测试手段对树脂的结构及热性能进行了研究.PCS分析结果表明:当甲基丙烯酸含量达到6％时,乳液可以获得良好的粒径分布及稳定性.TG和DTG分析结果表明:氟改性的丙烯酸酯树脂的热性能得到显著的提高.     

阳离子含氟聚氨酯乳液的制备及应用性能

以异佛尔酮二异氰酸酯(IPDI)、聚醚二元醇(PTMG1000)、三羟甲基丙烷(TMP)、N-甲基二乙醇胺(MDEA)和全氟烷基醇(FOH)为主要原料合成了阳离子水性含氟聚氨酯(WFPU)。利用FT-IR、TG分析了含氟聚氨酯的结构及热性能,通过透射电子显微镜(TEM)分析了乳液粒子形貌,通过测定表面张力、接触角分析了WFPU的表面性能。检测了涂膜浸水行为及耐蚀性能。结果表明:含氟单体和聚氨酯发生了聚合反应。TG结果表明WCPU的耐热性得到提高。TEM照片显示WFPU乳液粒子呈规则的球形,粒子分布较为均一。表面张力和接触角测试表明含氟聚氨酯具有低表面能。WFPU涂膜具有较高的防水性及优异的耐蚀性能。     

多臂UV固化含氟聚碳酸酯聚氨酯的制备及应用

聚碳酸酯二元醇(PCDL)与异佛尔酮二异氰酸酯(IPDI)反应后,再分别与丙烯酸羟乙酯(HEA)及十三氟辛醇反应,得到双键半封端物及含氟半封端物,随后以二聚甘油为核将两者按物质的量比1∶1反应得到多臂UV固化含氟PCDL基聚氨酯丙烯酸酯(FPUA)。采用傅里叶变换红外光谱(FT-IR)、核磁共振(1H-NMR)表征了FPUA的结构。并以其为添加剂,加入到市售聚氨酯中,制备了低表面能的疏水涂层,通过表面水油接触角、硬度及附着力测试,对疏水涂层的表面性能及物化性能进行了表征。     

硅烷改性氟代聚丙烯酸酯乳液的合成及其应用

在阳/非离子表面活性剂及引发剂作用下,将甲基丙烯酸十二氟庚酯、甲基丙烯酸十二醇酯、丙烯酸羟丙酯、甲基丙烯酸二甲氨乙酯、乙烯基三乙氧基硅烷进行乳液共聚,制得了硅烷改性的阳离子氟代聚丙烯酸酯乳液(FL-HDV)。用红外光谱(FT-IR)和核磁共振氢谱(1H NMR)对FLHDV主组分的结构进行了表征,用X射线光电子能谱仪(XPS)对乳液的成膜表面成分进行分析和表征,并讨论了硅烷改性前后及不同的整理工艺对其在涤纶织物上应用性能的影响。结果表明,与未用硅烷改性的氟代聚丙烯酸酯乳液(FLDH)对比,硅烷改性可以提高含氟聚合物的交联度,进而增加织物的拒水拒油性。XPS分析和接触角测定结果表明,在涤纶纤维表面明显存在有FLHDV膜,使得纤维与空气的界面上富集着疏水的含氟链段,而硅氧基团与纤维表面结合,从而赋予涤纶良好的拒水拒油性。在不同的工艺条件下,一浸一轧工艺处理的织物具有更高的拒水拒油等级,且弯曲刚度略低,柔软度较好。