四臂聚乙二醇/四氢呋喃星形嵌段共聚醚的实验研究

以四臂聚乙二醇(4a PEG)为大分子起始剂,三氟化硼乙醚(BF3·OEt2)为催化剂,在0℃冰水浴下用环氧丙烷(PO)引发四氢呋喃(THF)阳离子开环聚合合成出4a PEG/THF星形嵌段共聚醚。考察了4a PEG与THF质量比、PO用量、催化剂用量、反应时间对合成星形共聚醚产率、羟值和黏度的影响。用红外光谱(IR)、核磁共振(1H-MNR和13C-MNR)对星形共聚醚进行了表征。研究结果表明,合成星形共聚醚的较佳条件为THF与4a PEG质量比为3∶1,PO物质的量为THF物质的量的10%,催化剂物质的量为THF物质的量的3%,反应时间为1.5 h。     

高效液相色谱法在红霉素A肟贝克曼重排反应中的应用

建立了一种用于重排反应工艺监控和测定红霉素6,9亚胺醚及其相关化合物含量的反相高效液相色谱法,色谱柱为150mm×4 6mm,填料InertsilODS-3,粒径5μm,流动相为V(CH3CN)∶V〔c(KH2PO4)=0 033mol/L缓冲溶液〕=30∶70,流速0 8mL/min,柱温30℃;紫外检测波长205nm。该方法能够在12min内快速准确指认重排产物中化学性质差异较大的6种物质:红霉素A6,9亚胺醚、红霉素A9,11亚胺醚、红霉素A9位内酰胺、红霉素A8位内酰胺、红霉素E肟和Z肟,并且贝克曼重排产物在进样量13～100μg显示良好的线性关系(rA=0 9975;rB=0 9994;rC=0 9930)。     

HPLC在红霉素肟的醚化反应中的应用

在克拉霉素合成工艺中,红霉素肟的醚化保护是最重要的一步。作者研究确立了一种反相高效液相色谱法,能有效地对醚化产物红霉素A9 (1 异丙氧环己基)肟及其与工艺相关的化合物进行分离和定量分析。色谱柱为DIKMA公司的InertsilODS-3(150mm×4 6mm,粒径5μm)。流动相为V(乙腈)∶V〔c(KH2PO4)=0 033mol/L〕=48∶52,流速1 5mL/min,UV检测波长205nm,柱温30℃。肟醚在进样量为10～50μg内具有良好的线性关系,为醚化反应的工艺优化和监控提供了一个可在10min内快速而可靠的检测方法。作者还对红霉素A9 (1 异丙氧环己基)肟的E和Z异构体进行了定性分离和色谱行为研究,结果表明Z异构体比E的保留时间短,流动相V(乙腈)∶V〔c(KH2PO4)=0 033mol/L〕=45∶55时,分离度最好。     

二乙二醇葡萄糖苷聚氧丙烯醚的制备及性能

先采用二乙二醇和葡萄糖合成二乙二醇葡萄糖苷,以此为起始物,再与环氧丙烷(PO)反应,得二乙二醇葡萄糖苷聚氧丙烯醚,研究了催化剂用量、温度、压力、n(PO)/n(二乙二醇葡萄糖苷)等因素对反应及产物理化性能的影响。结果表明,适宜的合成工艺条件为:催化剂用量1.5%、温度125~135℃、压强0.2~0.3 MPa,在上述条件下反应速率较快。当聚合进料比n(PO)/n(二乙二醇葡萄糖苷)为13,制备产物的表面活性最高,其表面张力最低可达37.5 m N?m-1,产物乳化性能优良,可应用在低泡表面活性剂领域。     

聚乳酸/聚氧乙烯-聚氧丙烯醚嵌段共聚物共混体系的性能

采用熔融共混制备聚氧乙烯–聚氧丙烯醚嵌段共聚物增塑聚乳酸,研究聚氧乙烯–聚氧丙烯醚嵌段共聚物用量对聚乳酸/聚氧乙烯–聚氧丙烯醚嵌段共聚物共混体系流变性能、力学性能、热性能和微观结构的影响。当添加聚氧乙烯–聚氧丙烯醚嵌段共聚物的质量分数为20%时,聚乳酸/聚氧乙烯–聚氧丙烯醚嵌段共聚物共混体系的熔体流动速率为15.6g/(10min),比未增塑时提高约9倍,断裂伸长率为341.86%,撕裂强度为23.7N/cm,拉伸强度为44.5MPa,玻璃化转变温度从纯聚乳酸的60.1℃降到26.9℃。随着聚氧乙烯–聚氧丙烯醚嵌段共聚物用量的增加,共混体系的拉伸强度先下降后升高,断裂伸长率呈上升趋势,撕裂强度先下降后上升最后渐趋于稳定,聚乳酸链段的活动能力增强,增塑效果明显。扫描电子显微镜分析表明,当聚氧乙烯–聚氧丙烯醚嵌段共聚物质量分数≥12%时,共混体系脆冷断面的褶皱、粗糙度和裂纹明显增加,吸收能量能力增强,表现为断裂伸长率和撕裂强度提高。     

30%吡唑醚菌酯·叶菌唑水乳剂的高效液相色谱分析方法研究

采用高效液相色谱法测定30%吡唑醚菌酯·叶菌唑水乳剂,使用C_(18)色谱柱,以乙腈+0.3%冰乙酸水溶液(体积比70︰30)为流动相,在柱温25℃、波长230 nm、流量1.0 mL/min色谱条件下进行分析。吡唑醚菌酯和叶菌唑的标准偏差分别为0.032和0.028,变异系数分别为0.16%和0.27%,线性相关系数均为0.999 8,平均回收率分别为99.4%和99.6%。     

高效液相色谱法测定化妆品中p-茴香酸含量

建立高效液相色谱法测定化妆品中p-茴香酸的分析方法.经WondaSil C18柱(4.6 mm×250 mm×5μm)分离,高效液相色谱/二极管阵列检测器检测.流动相为V(甲醇):V(水):V(冰醋酸)=90:10:0.02,流速1.0 mL/min,柱温30℃,检测波长254 nm.结果表明,p-茴香酸质量浓度在1....     

烯丙基聚氧丙烯醚改性硅油的合成及其应用

为了解决硅油洗发水含硅量较高,对头发和头皮负担较重的问题,制备出一种新的聚氧丙烯醚改性硅油,代替纯硅油用于洗发水中.采用自制的烯丙基聚氧丙烯醚(相对分子质量约6000,简称DPPG-6000)与含氢硅油加成反应,通过单因素实验法考察了硅氢加成中反应物比例、催化剂用量、反应温度和反应时间等对产物的影响,确定了最佳反应条件...     

双草醚原药的高效液相色谱法研究

建立测定双草醚原药质量分数的分析方法。采用高效液相色谱,使用Promosil-C18色谱柱,以甲醇+水(体积比70∶30)为流动相,在流速为1.0 m L/min,230 nm波长下对双草醚进行定量分析。双草醚质量浓度在160.60~803.10 mg/L范围内,方法的线性相关系数为0.999 99,平均回收率为99.44%。方法准确、快速,适用于双草醚的定量分析。     

高效棉田苗后除草剂嘧硫草醚的高效液相色谱分析

采用Licrsorb-C18反相色谱柱和紫外检测器以甲醇和p H值4.0的醋酸水溶液为流动相,V(甲醇):V(醋酸水溶液)=65:35,波长265nm,对试样中嘧硫草醚含量进行液相色谱分离、测定。嘧硫草醚的保留时间为7.43min,变异系数为0.59%,回收率为99.5%-100.2%,线形相关系数为0.9948。     

Nanomechanical mapping of glass fiber reinforced polymer composites using atomic force acoustic microscopy

In this work, a dual‐frequency resonance tracking (DFRT) method was applied on atomic force acoustic microscopy (AFAM) and high‐resolution, quantitative nanomechanical mapping of a glass fiber–reinforced polymer composites (GFRP) was realized. Results show that even using the single‐frequency AFAM, the fiber, and epoxy can give very good contrast in amplitude images. The modulus mapping result on GFRP by DFRT AFAM was compared with that by dynamic nanoindentation, and it is found that DFRT AFAM can map the elastic modulus with high spatial resolution and more reliable results. The interface of GFRP was especially investigated using a 2 μm × 2 μm scanning area. Finite element analysis was implemented to investigate the effect of tip radius and the applied pressing force on the interface measurement using a sharp “interface”. By setting a linear‐modulus‐varied interface with finite width in finite element analysis (FEA), similar comparison between FEA and AFAM experimental results was also implemented. The average interface width is determined to be 476 nm based on the high‐resolution modulus image, indicating that AFAM is a powerful method for nanoscale interface characterization. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39800.     

A novel Bayesian inference soft sensor for real‐time statistic learning modeling for industrial polypropylene melt index prediction

A novel real‐time soft sensor based on a sparse Bayesian probabilistic inference framework is proposed for the prediction of melt index in industrial polypropylene process. The Bayesian framework consists of a relevance vector machine for predicting melt index and a particle filtering algorithm for soft sensor optimization. An online correcting strategy is also developed for improving the performance of real‐time melt index prediction. The method takes advantages of the probabilistic inference and using prior statistical knowledge of polymerization process. Developed soft sensors are validated with ten public databases from UCI machine learning repository and real data from industrial polypropylene process. Experimental results indicate the effectiveness of proposed method and show the improvement in both prediction precision and generalization capability compared with the reported models in literatures. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45384.     

对机械设备设计研发过程的讨论

本文对机械设备设计研发过程的基本步骤、工作方法及需要引起注意的问题进行了较详细的论述,并对机械设备设计研发工作的开展提出了一些建议.     

Generalizing solubility parameter theory to apply to one‐ and two‐dimensional solutes and to incorporate dipolar interactions

Hildebrand and Hansen solubility parameters are commonly used to identify suitable solvents for the dispersion or dissolution of a range of solutes, from small molecules to graphene. This practice is based on a number of equations, which predict the enthalpy of mixing to be minimized when the solubility parameters of solvent and solute match. However, such equations have only been rigorously derived for mixtures of small molecules, which interact only via dispersive forces. Herein, we derive a general expression for the enthalpy of mixing in terms of the dimensionality of the solute, where small molecules are considered zero‐dimensional, materials such as polymers or nanotubes are one‐dimensional (1D) and platelets such as graphene are two‐dimensional (2D). We explicitly include contributions due to dispersive, dipole–dipole, and dipole‐induced dipole interactions. We find equations very similar to those of Hildebrand and Hansen so long as the solubility parameters of the solute are defined in a manner which reflects their dimensionality. In addition, the equations for 1D and 2D systems are equivalent to known expressions for the enthalpy of mixing of rods and platelets, respectively, as a function of surface energy. This agreement between our expressions and those commonly used shows that the concept of solubility parameters can be rigorously applied to extended solutes such as polymers, nanotubes, and graphene. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

涂料研究开发新进展及关键科学与技术问题

阐述了近年来国内外涂料的研究开发现状,包括:利用新的树脂合成方法获得新的成膜物;直接引入无机纳米粒子以改善涂层性能;表面微纳结构构建以获得功能涂层等;提出了未来涂料技术的发展趋势,包括:环保化和健康化;通用涂层的高性能化;多功能化和智能化等;和需要突破的关键科学与技术问题。当企业发展到一定阶段和规模后,要加强科研开发的投入,加强产学研合作,加强基础研究,要敢于开发国外没有的技术和产品,敢于领先国外技术,才能真正成为涂料强国。     

TiO2‐Oligoaldaramide nanocomposites as efficient core‐shell systems for wood preservation

Homogeneous core‐shell systems were obtained with a growth, in controlled steps, of several oligoamides on TiO₂ nanoparticles. Derivatives of natural compounds, such as l ‐tartaric acid and α,α′‐trehalose, were used as diesters in the polycondensation reactions with ethylenediamine. TiO₂ anatase was chosen because of its high photo‐activity and its antimicrobial activity. The TiO₂ nanoparticles had been previously activated then functionalized using two different coupling agents, and finally, the TiO₂‐oligoamide nanocomposites were synthesized using two synthetic pathways. The final products were characterized by ¹H NMR, ¹³C NMR, FT‐IR, and transmission electron microscope. These nanocomposites can show improved properties in comparison with the single components (TiO₂ nanoparticles or oligoamides), which are useful in many fields, such as antimicrobial coatings for surfaces in cultural heritage conservation. A nanocomposite (TiO₂‐polyethylenetartaramide) was used for applicative studies, and it has shown a good efficacy against fungal attack by Trametes versicolor on wood specimens (Fagus sylvatica). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42047.     

Preparation and testing of Nafion/titanium dioxide nanocomposite membrane electrode assembly by ultrasonic coating technique

Membrane electrode assemblies with Nafion/nanosize titanium dioxide (TiO₂) composite membranes were manufactured with a novel ultrasonic‐spray technique (UST) and tested in proton exchange membrane fuel cell (PEMFC). The structures of the membranes were investigated by scanning electron microscopy (SEM), X‐ray diffraction (XRD), and thermogravimetric analysis. The composite membranes gained good thermal resistance with insertion of TiO₂. The SEM and XRD techniques have proved the uniform and homogeneous distribution of TiO₂ and the consequent enhancement of crystalline character of these membranes. The existence of nanometer size TiO₂ has improved the thermal resistance, water uptake, and proton conductivity of composite membranes. Gas diffusion electrodes were fabricated by UST. Catalyst loading was 0.4 (mg Pt) cm^?2 for both anode and cathode sides. The membranes were tested in a single cell with a 5 cm² active area operating at the temperature range of 70°C to 110°C and in humidified under 50% relative humidity (RH) conditions. Single PEMFC tests performed at different operating temperatures indicated that Nafion/TiO₂ composite membrane is more stable and also performed better than Nafion membranes. The results show that Nafion/TiO₂ is a promising membrane material for possible use in PEMFC at higher temperature. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40541.     

Poly(butylene succinate)/layered double hydroxide bionanocomposites: Relationships between chemical structure of LDH anion,delamination strategy,and final properties

A series of poly(butylene succinate) (PBS) containing organo‐modified layered double hydroxide (LDH) are prepared by melt compounding and by in situ polymerization of succinic ester and 1,4‐butanediol. Various LDHs intercalated with renewable organic anions are used. More specifically, lauryl sulfate, stearate, succinate, adipate, sebacate, citrate, and ricinoleate ions are used as LDHs organo‐modifiers. The thermal, rheological, and dynamic mechanical properties of the samples are investigated. The results reveal a general mechanical reinforcement imparted by the clays. Significant changes are observed for the in situ polymerized nanocomposites, especially for LDH stearate which improves the properties of PBS nanostructure, whereas very few differences are observed for the other samples. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1931–1940, 2013     

Synthesis and properties of cross‐linked polymers from epoxidized rubber seed oil and triethylenetetramine

A series of epoxidized oils were prepared from rubber seed, soybean, jatropha, palm, and coconut oils. The epoxy content varied from 0.03 to 7.4 wt %, in accordance with the degree of unsaturation of the oils (lowest for coconut, highest for rubber seed oil). Bulk polymerization/curing of the epoxidized oils with triethylenetetramine (in the absence of a catalyst) was carried out in a batch setup (1 : 1 molar ratio of epoxide to primary amine groups, 100°C, 100 rpm, 30 min) followed by casting of the mixture in a steel mold (180°C, 200 bar, 21 h) and this resulted in cross‐linked resins. The effect of relevant pressing conditions such as time, temperature, pressure, and molar ratio of the epoxide and primary amine groups was investigated and modeled using multivariable nonlinear regression. Good agreement between experimental data and model were obtained. The rubber seed oil‐derived polymer has a T_g of 11.1°C, a tensile strength of 1.72 MPa, and strain at break of 182%. These values are slightly higher than for commercial epoxidized soybean oil (T_g of 6.9°C, tensile strength of 1.11 MPa, and strain at break of 145.7%). However, the comparison highlights the potential for these novel resins to be used at industrial/commercial level. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42591.     

Lipid Composition,Natural Antioxidants and Physicochemical Characteristics in Liver Oil from Rajiforms from the Gulf of Mexico

Lipid composition by class, fatty acids, natural antioxidants (carotenes, tocopherols) and physicochemical characteristics of liver oil from three commercial rays, Rhinoptera bonasus (Chucha), Aetobatus narinari (Pinta) and Dasyatis americana (Bala) from the Gulf of Mexico were analyzed. Liver oil yield for R. bonasus, A. narinari and D. americana were of 43.04, 41.2 and 38.2% (wet weight), respectively. Triacylglycerols were the most abundant lipid by class in R. bonasus (68.9%), A. narinari (85.9%) and D. americana (81.6%), while sterols esters, sterols, di- and monoacylglycerides, polar lipids and wax esters were found in minor proportions. Species showed similar carotenes concentration, 8.7, 12.8 and 8.0 μg/g for R. bonasus, A. narinari and D. americana, respectively. α-tocopherol concentration was higher (p < 0.05) for A. narinari (46.7 mg/100 g) than for R. bonasus (21.0 mg/100 g) and D. americana (13.7 mg/100 g). Omega-3 polyunsaturated fatty acids in R. bonasus were high with docosahexaenoic acid (12.1%) in a higher proportion than eicosapentaenoic acid (7%).