明胶接枝共聚丙烯酸铵-丙烯酰胺

研究了溶液聚合法制备明胶-聚(丙烯酸铵-丙烯酰胺)(G-g-PAA/PAM)可降解高吸水性树脂的方法.对明胶/单体及丙烯酸铵/丙烯酰胺质量比、丙烯酸中和度、单体浓度及N,N'-亚甲基双丙烯酰胺和过硫酸钾相对含量影响产品吸(盐)水性能的情况进行测试,从中优选出较合适的反应条件,并用红外光谱对产物进行表征.该高吸水性树脂的吸水倍率达1187g/g,吸盐水倍率选82g/g.FTIR分析表明,反应产物为明胶与丙烯铵、丙烯酰胺的接枝共聚物.     

紫外光固化法合成St/AMPS/AM三元共聚高吸水性树脂

采用紫外固化法,以淀粉(St)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、丙烯酰胺(AM)为单体,N,N'-亚甲基双丙烯酰胺(NMBA)为交联剂,在不加引发剂和任何气氛保护下,合成出St/AMPS/AM/共聚高吸水性树脂,考察了反应条件对树脂吸水倍率的影响,并借助红外、偏光显微镜对树脂的分子结构及表面形态进行了表征。结果表明,在优化条件下合成的高吸水性树脂吸蒸馏水倍率为2354g/g,吸盐率可达145g/g(0.1mol/L)。     

二元共聚高吸水性树脂PAMA的吸液与保水性能

采用溶液聚合方法,以丙烯酰胺(AM)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为单体,N,N′-亚甲基双丙烯酰胺(NMBA)为交联剂,过硫酸钾(KPS)为引发剂合成了高吸水性树脂PAMA,并进行了吸液、保水性能研究。研究表明该树脂吸水倍率2451 g/g,吸生理盐水倍率119 g/g,对纯甲醇的吸液倍率(277 g/g);对吸液速率结果通过回归分析得吸蒸馏水时Qw=862.6t0.1855,吸生理盐水时Qs=52.0t0.1317。该吸水树脂具有优良的耐温保水性能和较好的热稳定性,且保水率与恒温时间呈线性关系,并能有效提高砂土的饱和含水量,可对砂土进行有效的改良。     

FP-g-P(AA-co-AM)高吸水树脂的制备

研究了鱼蛋白(FP)接枝聚合丙烯酸(AA)和丙烯酰胺(AM)制备蛋白改性高吸水性树脂的方法.通过对产品吸(盐)水性能的测试,得到合成产品的合适条件为:鱼蛋白、引发剂和交联剂相对单体的量分别约为7.5%、1.0%和0.025%,丙烯酸与丙烯酰胺的质量比为9:1,丙烯酸中和度为90%,单体质量分数为18%.在此条件下制备的高吸水性树脂,其吸水倍率达1061g/g,吸盐水倍率达136g/g.并用红外光谱对产物进行了表征.     

玉米秸秆基高吸水性树脂的合成及其性能的研究

采用水溶液聚合法将丙烯酰氧乙基三甲基化铵(DAC)、丙烯酰胺(AM)、丙烯酸(AA)3种单体接枝到纤维素骨架中合成玉米秸秆基两性高吸水性树脂。研究单体用量、秸秆用量、交联剂用量、引发剂用量、反应温度、反应时间和中和度对高吸水性树脂吸液率的影响。通过扫描电镜图、红外光谱图对其形貌进行表征。实验结果表明,在秸秆、AA、AM、DAC的质量分别为1、5、1和0.5g,引发剂用量占单体比率为1.2%,交联剂用量占单体总量比率为0.1%,中和度为75%,反应时间为3h,反应温度为60℃的合成条件下,制备的高吸水性树脂(SAR)吸液率达最大,其吸水率为235.9g/g,0.9%NaCl溶液的吸收率为31.3g/g。     

淀粉基接枝丙烯酸钠复合高吸水树脂材料的制备及性能测试

以丙烯酸和可溶性淀粉为主要原料,过硫酸铵为引发剂,N-N'-亚甲基双丙烯酰胺为交联剂,丙烯酰胺为单体,采用水溶液聚合法合成高吸水树脂(SAR).通过设计L25(55)正交试验,确定SAR制备条件,并分别添加适量高岭土、蒙脱土、锂皂石制备复合高吸水性树脂.利用FT-lR和SEM-EDS、TG等对复合高吸水性树脂进行表征.考察复合高吸水性树脂的吸液性能与保水性.SAR实验条件为:丙烯酰胺与淀粉质量比5:4、合成温度45℃、引发剂0.13 g、交联剂0.01 g、氢氧化钠9 g.结果表明:此条件下的SAR吸水倍率最大为179.5 g/g,吸盐倍率为70.75 g/g.FT-lR和SEM-EDS结果显示树脂已成功制备.无机物高岭土、蒙脱土、锂皂石的加入提高了SAR的吸液性能及热稳定性,其中含高岭土SAR的吸水倍率和吸盐倍率均达到最大,吸水倍率为245.0 g/g,吸盐倍率为83.3 g/g.     

敞开体系快速水溶液聚合法合成高吸水性树脂的研究

对丙烯酸(AA)、丙烯酰胺(AM)的水溶液聚合反应进行了研究,合成了高吸水性树脂,探讨了中和度、单体配比、交联剂用量、引发剂用量、水浴温度等对高吸水性树脂吸液倍率的影响,并用红外光谱对产物的结构进行了表征.5min合成的高吸水性树脂吸水倍率高达1600g·g-1,在质量分数为0.9%的食盐水中的吸液倍率达155g·g-...     

鱼蛋白接枝聚合丙烯酸高吸水树脂的制备

用溶液聚合法制备了鱼蛋白基丙烯酸(FP-g-AA)高吸水性树脂。采用单因素法改变组分配比分别进行合成试验。并通过对产品的吸(盐)水性能的测试,优化合成配方及用红外光谱仪对产物进行表征。结果表明,当过硫酸钾、N,N′-亚甲基双丙烯酰胺、鱼蛋白用量分别为丙烯酸的1.0%、0.07%、10.0%,丙烯酸的中和度和在溶液中的质量分数分别为80%和18%时,该高吸水性树脂的吸水倍率达981g/g,吸生理盐水(0.9%NaCl)倍率达127g/g。红外光谱也显示,产品为鱼蛋白接枝聚合丙烯酸树脂。     

微波辐射凹凸棒接枝AMPS/AM高吸水树脂的制备和表征

以N,N′-亚甲基双丙烯酰胺(NMBA)为交联剂,过硫酸钾(KPS)为引发剂,采用微波辐射方法制备了凹凸棒(APT)接枝2-丙烯酰胺基-2-甲基丙磺酸(AMPS)/丙烯酰胺(AM)耐盐性高吸水性树脂。探讨了单体配比、微波功率(P)、中和度(N)、APT用量、NMBA用量和KPS用量对待测液体吸水倍率的影响,用红外光谱(FT-IR)、X射线衍射(XRD)对高吸水性树脂进行了表征。实验结果表明,在最佳合成条件(n(AM)∶n(AMPS)=4.5∶1,P=390W,N=75%,w(NMBA)=0.08%,w(KPS)=0.6%,w(APT)=7.5%)下树脂在去离子水中的吸水倍率为1460 g/g,吸生理盐水倍率为114 g/g,树脂具有较强的耐盐性能;红外光谱(FT-IR)和X射线衍射(XRD)表征显示,凹凸棒和有机单体之间发生了接枝共聚反应,其反应仅在凹凸棒的表面进行,单体并没有插入到凹凸棒的层间。     

丙烯酸-2-丙烯酰胺基-2-甲基丙磺酸-滤渣高吸水性树脂的制备

以N,N-亚甲基双丙烯酰胺为交联剂,过硫酸钾-亚硫酸氢钠为引发剂,丙烯酸(AA)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为单体,采用水溶液聚合法合成了丙烯酸-2-丙烯酰胺基-2-甲基丙磺酸-滤渣高吸水性树脂.考察了交联剂、引发剂、单体的质量比、AA中和度、反应温度、滤渣含量对树脂吸水率的影响.经正交实验制得的高吸水性树脂在24h内吸水达到饱和,吸蒸馏水1397g/g,自来水330g/g,0.225moL/L NaCl溶液79g/g.该树脂具有一定的耐盐性.     

Flame retardance and thermal stability of wool fabric treated by boron containing silica sols

In order to improve flame retardance and thermal stability of wool fabric, a series of boron doped silica sols were prepared from a tetraethyl silicate inorganic precursor and applied to wool fabric as a flame retardant finish through the sol–gel process. Boric acid, zinc borate and ammonium borate were used as flame retardant additives. The effect of the boron containing flame retardant doped sol coatings on flammability, combustion behavior and thermal property of treated wool fabric was investigated via limited oxygen index (LOI) test, vertical burning test, thermogravimetric (TG) analysis, micro-calorimeter combustion (MCC) and smoke density test. It was found that the coatings on wool fabric acted as a heat insulation barrier, increasing the carbon residue and slowing down the spread of flame when burning, thus improving the flame retardance and thermal stability of the treated fabric. Meanwhile, the smoke density result indicated that the NH₄HB₄O₇ doped silica sol treated fabric had good smoke suppression property. Furthermore, the result of mechanical properties showed that there was no damage on tensile strength and air permeation of treated wool fabric.     

Synthesis of organic-inorganic hybrid sols with nano silica particles and organoalkoxysilanes for transparent and high-thermal-resistance coating films using sol-gel reaction

Organic-inorganic hybrid sols were synthesized from nano silica particles dispersed in water and from organoalkoxysilanes, using the sol-gel reaction. This work focuses on the effects of the three multifunctional organoalkoxysilanes dimethyldimethoxysilane (DMDMS), methyltrimethoxysilane (MTMS), and tetramethoxysilane (TMOS) to form a transparent and high-thermal-resistance coating film. The stability of the hybrid sol was evaluated as a function of the reaction time for 10 d through the variation of the viscosity. The viscosity of the silica/DMDMS and silica/MTMS sol was slightly increased for 10 d. The multifunctional organoalkoxysilanes formed dense silica networks through hydrolysis and condensation reaction, which enhanced the thermal resistance of the coating films. No thermal degradation of the silica/DMDMS sample occurred up to 600 degrees C, and none of the silica/MTMS and silica/TMOS samples occurred either up to 700 degrees C. The organic-inorganic hybrid sols were coated on the glass substrate using a spin-coating procedure. The organic-inorganic hybrid sols formed flat coating films without cracks. The transmittance of the hybrid sol coating films using MTMS and DMDMS was shown to be over 90%. The transmittance of the silica/TMOS sol coating film reacted for 10 d abruptly decreased due to faster gelation. The silica/DMDMS and silica/MTMS hybrid sols formed smooth coating films while the surface roughness of the silica/TMOS coating film markedly increased when the hybrid sol reacted for 10 d. The increase of the surface roughness of the silica/TMOS coating film can be attributed to the degradation of the stability of the hybrid sol and to the loss of transmittance of the coating film. It was confirmed in this study that the use of organic-inorganic hybrid sol can yield transparent and high-thermal-resistance coating films.     

Preparation of silica fibers and non-woven cloth by electrospinning

Silica fibers, which can potentially be used as filters and media for catalysts immobilization, were successfully spun via electrospinning process with precursor prepared through the sol–gel synthesis. Spinnable sols can be obtained only when the molar ratio of water to TEOS is less than 2 which is consistent with the retrospective results derived for other spinning methods. It was confirmed for the first time that the reaction time can be drastically reduced by introducing humidified air, controlled by KCl saturated aqueous solution, during sol–gel process. The size of obtained silica fibers is about 4.5 μm and has a certain degree of flexibility and mechanical strength. Although the specific surface area of as spun fiber was 7.7 m²/g, which is apparently small comparing to generic silica, treatment by boiling water only for 5 min could increase the specific surface area to be about 500 m²/g.     

Ductile PLA nanocomposites with improved thermal stability

Polylactide (PLA) is used as a biomedical material because it is biodegradable, but the vast majority of biodegradable polymers in clinical use are composed of rather stiff materials that are unsuitable for use in numerous applications because they exhibit limited extendibility, weak mechanical strength, and poor thermal stability. We modified PLA with 2-methacryloyloxyethyl isocyanate (MOI) to prepare ductile PLA materials. By utilizing a novel sol–gel process, PLA nanocomposites were further prepared with improved mechanical properties and thermal stability. The 10% thermal decomposition temperature for PLA modified with 5% MOI and 5–10% silica was 21–32 °C higher than that of original pristine PLA. Elongation at break increased by 4–13 times when compared to neat PLA while the tensile strength was maintained at 30–40 MPa. These synthesized PLA nanocomposites can be applied as biomaterials with improved mechanical and thermal properties.     

Si基多孔 SiO2薄膜驻极体电荷储存稳定性

通过控制溶胶－凝胶（sol-gel)工艺条件,利用相应条件下样品的红外光谱,等温表面电位衰减,开路热刺激放电电流谱等,考虑了Si基多孔SiO2薄膜驻极体体内沉积的空间电荷的储存稳定性,分析了各种工艺参数与薄膜驻极体性质之间的联系。实验结果表明,反应物中水含量对簿膜驻极体的电荷储存稳定性及陷阱分布有一定的影响;烧结温度和时间对电荷的储存稳定性的影响较大。     

Feasibility study of silica sol as the carrier of a hydrophobic drug in aqueous solution using enrofloxacin as the model

The aim of this study was to determine the feasibility of using silica sol to carry a hydrophobic drug in aqueous solution. Enrofloxacin, which was selected as the model drug because it is a broad-spectrum antibiotic drug with poor solubility in water, was adsorbed onto silica sol in aqueous solution during cooling from 60 °C to room temperature. The drug-loaded silica sol was characterized by transmission electron microscopy, Fourier transform infrared spectrum, thermal gravimetric analysis and ultraviolet–visible light spectroscopy. The results showed that enrofloxacin was adsorbed by silica sol without degradation at a loading of 15.23 wt.%. In contrast to the rapid release from pure enrofloxacin, the drug-loaded silica sol showed a slower release over a longer time. Kinetics analysis suggested the drug release from silica sol was mainly a diffusion-controlled process. Therefore, silica sol can be used to carry a hydrophobic drug in aqueous solution for controlled drug delivery.     

Preparation and Properties of Slag Wool Board using Modified Polyvinyl Alcohol as Binder

Slag wool boards were produced by using slag wool as the main raw material and adding modified polyvinyl alcohol (PVA) as the binder. The microstructure, thermal conductivity, compression strength, hydrophobicity, and other properties of the slag wool board were analyzed by using scanning electron microscopy, thermal conductivity tester, electronic universal testing machine, and other equipments. Also, the influence of different types and amount of binder on the properties of the slag wool board was studied. The results show that the addition of silica sol can improve the high temperature resistance of the slag wool board, and the addition of borax can improve the hydrophobic rate and compression strength of the slag wool board. Also, the concentration of PVA has obvious influence on the usage of silica sol and borax. In this study, we found that the optimal ratio of the binder should be 3 wt% addition of PVA, 20 wt% addition of silica sol, and 0.2 wt% of borax (relative to the amount of PVA), under the condition of satisfying the performance index of slag wool board and the convenience to spray the adhesive.     

碳纤维水性杂化上浆剂的制备及其上浆后力学性能

以一定比例的甲基三乙氧基硅烷、正硅酸乙酯、对甲苯磺酸、γ-氨丙基三乙氧基硅烷、无水乙醇制备含硅溶胶,将含硅溶胶和聚醚型水性聚氨酯的水溶液以一定比例复合,制备碳纤维水性杂化上浆剂。研究了不同配比对上浆剂平均粒径和稳定性的影响,结果表明:当水性聚氨酯含量为0.02g/mL时,上浆剂乳液平均粒径为99.94nm,粒径分布较窄,稳定性较好;使用制备的杂化上浆剂对碳纤维进行上浆处理,结果显示:上浆后碳纤维单丝拉伸强度较商用碳纤维提高4.45%,较未上浆碳纤维提高11.04%;与环氧树脂复合后的复合材料界面剪切强度比商用碳纤维增强环氧树脂复合材料的提高了13.74%。     

助溶剂驱使溶胶-凝胶化SiO_2/聚丙烯酸酯复合涂层

采用助溶剂和硅烷偶联剂(Z-6040)对碱性硅溶胶进行复合改性后添加到聚丙烯酸酯乳液中制备SiO2/聚丙烯酸酯杂合乳液(Si/PAE),分别考查助溶剂的种类和用量对硅溶胶的溶胶-凝胶化(sol-gel)反应及复合涂层综合性能的影响,结果发现:异丙醇是合适的助溶剂,其最佳添加量为硅溶胶质量的10%。TEM测试和纳米粒径分析发现:助溶剂可以提高无机硅颗粒在杂合乳液中的分散能力,降低Si/PAE的平均粒径。傅里叶红外光谱(FT-IR)和原子力显微镜(AFM)分析说明:Si/PAE乳液在成膜过程中,助溶剂可驱使硅溶胶发生sol-gel反应,并在涂层表面富集含硅聚合物,Si/PAE的涂层结构平整且致密。TGA分析发现:Si/PAE涂层具有较好的热稳定性。     

电纺制备聚丙烯腈/聚偏氟乙烯复合纤维膜及其空气过滤性能

以聚偏氟乙烯(PVDF)为芯层,聚丙烯腈(PAN)为皮层,通过同轴法静电纺丝技术制备PAN/PVDF纳米复合纤维膜。通过向纤维膜的皮层中加入纳米硅粉、气相白炭黑、硅溶胶三种不同的纳米粒子和改变皮芯层溶液挤出速度对PAN/PVDF纳米纤维膜进行结构优化。同时,采用BET、SEM、水接触角、纤维强度仪等对纤维膜的孔结构参数、表面形貌、亲水性、力学性能等进行研究。结果表明:在皮层中加入硅溶胶后的溶液导电能力达到32.90 μL/cm,PAN/PVDF纤维膜力学性能最好,纵向断裂强度达到13.02 MPa。含有硅溶胶的口罩布的品质因子达到0.0236,远大于纯聚丙烯(PP)无纺布的品质因子(0.0127),过滤性显著提高。