Preparation and Characterization of Two-component Waterborne Poly-urethane Comprised of Water-soluble Acrylic Resin and HDI Biuret

A two-component waterborne polyurethane （2K-WPU） was prepared by mixing water-soluble acrylic resin and hexamethylene diisocyanate biuret, and then diluted for phase inversion with water. Compared with water-soluble acrylic resin, the phase inversion of 2K-WPU occurs at lower water content. It is indicated by TEM that 2K-WPU particles show a core-shell structure, in which HDI biuret is encapsulated by hydrophilic acrylic resin. 2K-WPU emulsion with HDI biuret has larger particle size and narrower distribution index, while for 2K-WPU emulsion with HDI isocyanurate, the latex not only has large particle size, but also has two-peak distribution. FTIR shows that the reaction between HDI biuret and acrylic resin can complete in 12h. In addition, studies on effect of composition of acrylic resin on performance of 2K-WPU show that narrowing the polar difference between water-soluble acrylic resin and HDI biuret and improving the miscibility of two components are the key to prepare the transparent and high gloss films with high crosslinking density.     

OptimalParameters of Response Surface Methodology for Preparation of Magnesium Hydroxide Flame Retardant

The yield of magnesium hydroxide was investigated via response surface methodology using bischofite and aqueous ammonia as raw materials. The experimental results indicated that the effects of reaction temperature, magnesium ion and aqueous ammonia concentrations on the yield of magnesium hydroxide gradually decreased. In particular, reaction temperature and magnesium ion concentration had a significant influence on the yield. After the regression and fitting of the response value and each factor, the regression equation was obtained. As proven by experiments, the predicted value and actual value showed a good fit. The products of the center experiment were characterized by particle size analysis, scanning electron microscopy, and X-ray diffraction. The results show that the morphology is irregular and shows a lamellar structure. The particles have a narrow size distribution ranging from 0.64 to 0.68 mm of D50 size. The difference in particle size of D10 and D90 is less than 0.91 mm, and the purity very high.     

搅拌式有限氧补偿条件下乳状液中多不饱和脂肪酸氧化模型

The oxidation of polyunsaturated fatty acids （PUFA） in emulsion with stirring and limited oxygen compensation was studied. A mathematical model of diffusion-oxidation was developed considering the mass transfer resistance of a gas-liquid boundary, the resistance of the boundary layer from the emulsifier membrane, and the autocatalytic-type autoxidation reaction of PUFA. The dynamic mass transfer coefficient of the emulsifier membrane, k0, was introduced. The model was verified by comparing the predictions of the model with the experi- mental data. The results indicated that the model was in good agreement with the oxygen diffusion and linoleic acid oxidation in the emulsion, and showed good applicability in the prediction of the effect of the emulsifier type on the oxidation of PUFA in the emulsion. It indicated that the oxidation of PUFA in emulsions, with stirring and limited oxygen compensation from the atmosphere, was controlled mostly by mass transfer resistance from the emulsifier membrane.     

STUDIES ON SYNTHESIS OF SILICA SOL-ORGANIC POLYMER COMPOSITE EMULSION

An emulsion of polystyrene/poly (butylacrylate-methyl methacrylate acrylic acid) core/shell latex particles (PS/P (BA-MMA-AA)) has been prepared by use of three synthetic methods. The effects of synthetic methods on the distribution of carboxyl groups in latex particles were studied. The results show that the seed emulsion polymerization in which the pre-emulsified monomers were added by dropping method to the second stage is the best technique for obtaining the optimum distribution of carboxyl groups on the surface of the latex particles. Furthermore, by using PS/P (BA-MMA-AA), a type of novel composite emulsion of silica sol-PS/P (BA-MMA-AA) was synthesized with the above method. By observation through transmission EM, the morphology of the latex particles obtained shows that a composite structure has been formed between silica sol particles and organic polymer particles.     

硅溶胶/苯乙烯-丙烯酸酯共聚物无机-有机杂化水分散液的制备和表征

A stable silica sol with 3-5 nm in diameter, which can form homogeneous film without crack, was prepared and characterized. Then, the inorganic-organic hybrid aqueous dispersion composed of such a silica sol and an emulsion of styrene （St） and acrylate （Ac） copolymer was prepared and the hybrid effect between the silica sol and poly（St-co-Ac） was observed by Fourier transform infra-red （FT-IR） spectroscope. The toughness of the film prepared by this kind of hybrid aqueous dispersion was excellent, as it was enhanced appreciably by commixing with a small amount of poly（St-co-Ac） emulsion. Some amino-polysiloxane modified hybrid aqueous dispersions were also prepared and the properties of the modified dispersions and their films were investigated. The experimental results showed that the film prepared with such an amino-polysiloxane modified hybrid dispersion exhibited excellent hydrophobicity and low surface energy after heat treatment for 1.5 h, during which the formation of the graft copolymer was observed. The surface energy of this film decreases as a result of the enrichment of siloxane segments on the film surface.     

用含夹带剂丙酮的超临界CO2快速膨胀法制备灰黄霉素的微细颗粒

Griseofulvin (GF) is an antifungal drug whose pharmaceutical activity can be improved by reducing particle size. In this study the rapid expansion of supercritical solution (RESS) was employed to micronize GF.Carbon dioxide with cosolvent acetone was chosen as a supercritical mixed solvent. The solubility of GF in super-critical CO2 with cosolvent acetone was measured using a dynamic apparatus at pressures between 12 and 32 MPa,temperatures at 313, 323 and 333 K and cosolvent concentration at 1.5, 3.0, 4.5 and 6.0% (by mole). The effect of pre-expansion pressure, extraction temperature, spraying distance, nozzle size and concentration of cosolvent on the precipitated particles was investigated. The results show that the mean particle size of griseofulvin precipitated by RESS was less than 1.2μm. An increase in pre-expansion pressure, extraction temperature, spraying distance and concentration of cosolvent resulted in a decrease in particle size under the operating condition studied. With the decrease of nozzle diameter the particle size reduces. The crystallinity and melting point of the original material and the processed particle by RESS were tested by X-ray diffraction (XRD) and differential scanning calorimetry (DSC).No evident modification in the crystal habit was found under the experimental conditions tested. The morphology of particles precipitated was analyzed bY scanning electron microscopy (SEM).     

悬浮态乳液聚合条件对聚氯乙烯树脂颗粒特性的影响

Suspended emulsion polymerization of vinyl chloride was carried out in a 5 L autoclave. The influence of agitation, polymerization conversion, dispersant and surfactant on the average particle size (PS) and particle size distribution (PSD), particle morphology and porosity of polyvinyl chloride (PVC) resin was investigated. It showed that the agitator had great influence on the smooth operation of polymerization, PS and PSD. The PS increased and PSD became narrow as polymerization conversion became high. The porosity decreased with the increase of conversion. A convenient choice of additives, both dispersants and non-ionic surfactants, allows one to adjust PS and PSD. The PS decreased with the addition of polyvinyl alcohol or hydroxypropyl methylcellulose dispersants,and increased with the addition of Span surfactants. The addition of dispersants or surfactants also affected the morphology and porosity of resin, and PVC resin with looser agglomeration and homogeneous distribution of primary particles was prepared.     

反应沉淀法制备超细硫酸沙丁胺醇颗粒及其粉雾剂的表征

The preparation of ultra-fine particles of salbutamol sulphate （SS） was accomplished with a reactive precipitation pathway, in which salbutamol and sulphuric acid were Used as reactants with the solvents of ethanol.The effects of sulphuric acid concentration, reaction temperature, stirring rate, and reaction time onthesize of the particle were investigated. A binary mixture composed of lactose and SS was prepared to evaluate SS. The results showed that ultra-fine SS particles with controlled diameters ranging between 3 μm and 0.8 μm and with a narrow distribution could be achieved. The morphology consisting of clubbed particles wassuccess.fully obtained. The purity of the particles reached above 98% with-UV detection. The dose- of dry powder inhalation was obtained by blending the particles with recrystallized lactose, which acted as a carrier. The deposition quantity of the drug in breathing tract was estimated using a twin imPinger apparatus. Compared with the Shapuer powder （purchased in the market）, the results showed that SS_particles had more quantifies.subsided in simulative lung.. _     

Characterization and analysis of petrochemical wastewater through particle size distribution,biodegradability, and chemical composition

The centralized treatment method is a widely used form of wastewater treatment that tends to be less effective at removing toxic substances. Therefore, a detailed analysis of the composition of wastewater can provide important information for the design of an effective wastewater treatment process. The objective of this paper was to investigate particle size distribution(PSD), biodegradability, and the chemical composition of the petrochemical wastewater discharges. For this purpose, this project selected the petrochemical wastewater and treated wastewater of China National Offshore Oil Corporation Zhongjie Petrochemical Co, Ltd. as the analysis objects.The step-by-step filtration method, along with a molecular weight classification method, was selected to build the chemical oxygen demand(COD) and biochemical oxygen demand(BOD) fingerprints of petrochemical wastewater and treated wastewater. The results showed that the main pollutants were settleable particles in petrochemical wastewater, which contributed to over 54.85% of the total COD. The colloidal particles with particle sizes in the range of 450–1000 nm had the highest COD value in the treated wastewater, which contributed34.17% of the total COD of treated wastewater. The results of the BOD analysis showed that the soluble fractions were the main reason that treated wastewaters did not meet the treatment standards. Tests on the organic compounds in petrochemical wastewater found that there were mainly linear paraffins, branched paraffins, benzene series compounds, and some plasticizers in the influent of the petrochemical wastewater. The most abundant pollutants in treated petrochemical wastewater were the adjacent diisobutyl phthalate and the linear alkanes.Fourier transform infrared(FTIR) transmission spectroscopy analysis showed that the settleable particles of petrochemical wastewater and membrane bioreactor(MBR)-treated wastewater contained multiple types of organic substances. The results also indicated that removing the oil-settleable substances, the colloidal particles(450–1000 nm), and the soluble organics will be necessary for the treatment of petrochemical wastewater.     

BUBBLE FORMATION FREQUENCY STUDY IN A SINGLE-JET GAS-SOLID FLUIDIZED BED

Bubble formation frequencies in a single orifice two-dimensional gas-solid fluidized bed(292mm×16 mm)were measured by means of a high-sensitivity capacitance probe.A spectrum analyzer was used toanalyze the bubble frequency distribution.The effects of a series of parameters,including particle size(0.105—0.590 mm),particle density (590-2990 kg/m~3),minimum fluidization velocity of particles(0.0072-0.481 m/s),initial bed height (205-565 mm),probe vertical location,jet gas flow rate(0.5-35×10~(-4)m~3s)and background fluidizing gas velocity (0-3 times of minimum fluidization velocity),on the bubble frequencypower spectrum density were investigated.For the fluidized bed with small particles of low density,the bubble formation frequency was in goodagreement with Davidson and Harrison model.The data showed a regular deviation from that model asparticle size and density increased.The model is then modified to account for the fact that with largeparticles,gas will leak from the forming bubble into the surrounding emulsion phase.The modifed leakagemodel agrees with the experimental results.     

核壳型含氟丙烯酸酯乳液的合成及表征

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、甲基丙烯酸六氟丁酯(HFMA)等为主要原料,采用多步乳液聚合法,合成了具有核壳结构的含氟丙烯酸酯乳液。实验结果表明,主要单体质量比m(MMA)∶m(BA)=45∶55,核壳单体质量比为6∶4,含氟单体质量分数为7%,乳化剂质量分数为3%~4%时,制备得到的含氟丙烯酸乳胶粒子具有软核/硬壳结构,粒径为120 nm,乳胶膜吸水率为7%。通过傅里叶红外光谱法(FTIR)对乳液结构进行表征,结果表明,含氟单体参与了有效聚合;差示量热扫描(DSC)和热重分析法(TG)分析结果表明,聚合物存在两个玻璃化温度(-10.2℃和58.4℃),且热分解温度比不含氟的聚合物提高了59℃;接触角测试结果表明,当w(HFMA)≥7%时,乳胶膜正面与水的接触角为98.2,°说明所合成的核壳结构含氟丙烯酸酯乳液中有机氟富集于壳层,涂膜的耐热、疏水性良好。     

纳米SiO2/聚氨酯-含氟丙烯酸酯杂化乳液的合成与表征

采用种子乳液聚合法,以聚氨酯（PU）乳液为种子（在聚合过程中为壳相）,甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）、甲基丙烯酸十二氟庚酯（DFMA）和γ-甲基丙烯酰氧丙基三甲氧基硅烷（KH-570）改性的纳米SiO₂组成的混合物为核相,合成了具有核壳结构的纳米SiO₂/聚氨酯-含氟丙烯酸酯（SiO₂/FPUA）复合乳液。考察了纳米SiO₂和DFMA用量对乳液聚合过程及乳胶膜性能的影响。通过傅里叶红外光谱（FT-IR）、接触角（CA）、透射电子显微镜（TEM）、热重（TG）、差示扫描量热仪（DSC）和力学性能测试（MPT）等表征乳液的结构形态、乳胶膜的表面性能和综合性能。结果表明：乳胶粒子呈现“反相核壳”结构,以聚丙烯酸酯（PA）相为核,PU相为壳;由于纳米SiO₂和DFMA的协同作用,涂膜的疏水性和综合性能得到了较大的提高。     

n-BMA/MMA共聚核壳乳液的合成研究

通过半连续种子乳液聚合的方法,制备了具有核壳结构的丙烯酸酯聚合物乳胶粒子。采用甲基丙烯酸甲酯(MMA)、甲基丙烯酸酯正丁酯(n-BMA)等单体进行共聚。研究了共聚合过程中,乳化剂浓度、引发剂等对聚合物乳液粒径大小、凝胶量等的影响,并利用动态光散射(DLS)、透射电镜(TEM)和差示扫描量热仪(DSC)对乳胶粒子进行表征。结果表明:核乳液聚合阶段乳化剂浓度增大,乳液粒子的粒径变小,引发剂用量对粒径及分布影响不大;TEM观察到核乳胶粒径大小及变化趋势与DLS测得的结果相一致,并且核乳胶粒子和核壳乳液粒子都呈规则的圆球状,分布均一;DLS测试核壳丙烯酸酯乳胶粒子粒径的变化呈逐渐增长的趋势;DSC测试发现制备的核壳粒子有2个玻璃化转变温度(Tg),验证了胶乳粒子核壳结构的存在。     

核壳型纳米SiO2/含氟聚丙烯酸酯复合乳液的合成与表征

采用原位乳液聚合法,在可聚合阴离子乳化剂/非离子乳化剂复配体系下,以γ-甲基丙烯酰氧丙基三甲氧基硅烷(KH-570)改性的纳米SiO2、甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、丙烯酸(AA)等为核相组成,以MMA、BA及甲基丙烯酸十二氟庚酯(DFMA)为壳相单体,合成纳米SiO2/含氟聚丙烯酸酯复合乳液.考察了纳...     

自制反应性乳化剂制备的含氟核壳乳液及性能

采用烷基酚聚氧乙烯醚（OP-10）与顺丁烯二酸酐反应,制得反应性乳化剂;以甲基丙烯酸甲酯（MMA）和丙烯酸丁酯（BA）为核,甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）和甲基丙烯酸十二氟庚酯（DFMA）为壳,采用半连续种子乳液聚合方式制备核壳型含氟丙烯酸酯乳液。对反应性乳化剂的性能进行了初步探究,并通过红外光谱、TEM、DSC、CA、TGA等对体系进行了研究。结果表明,自制的反应性乳化剂性能优异,合成的乳胶粒具有典型的核壳结构,乳液性能稳定;反应性乳化剂的引入使涂层具有较低的表面能,有效地提高了乳胶膜的疏水性能。     

改性纳米SiO2/聚氨酯-含氟丙烯酸酯无皂乳液合成及其胶膜性能表征

引言水性聚氨酯相对溶剂型聚氨酯具有不燃、气味小、不污染环境等优点[1-2],从而广泛用于涂料[3]、胶黏剂[4]、油墨[5]等领域。目前,常用于软包装领域的薄膜主要是表面能很低的非极性膜,而水性聚氨酯胶黏剂具有较高的表面自由能,对非极性膜的润湿性差,因此需要降低水性聚氨酯的表面张力,达到润湿非极性膜的目的。     

Preparation and surface properties of core‐shell polyacrylate latex containing fluorine and silicon in the shell

The core‐shell polyacrylate latex particles containing fluorine and silicon in the shell were successfully synthesized by a seed emulsion polymerization, using methyl methacrylate (MMA) and butyl acrylate (BA) as main monomers, dodecafluoroheptyl methacrylate (DFMA), and γ‐(methacryloxy) propyltrimethoxy silane (KH‐570) as functional monomers. The influence of the amount of fluorine and silicon monomers on the emulsion polymerization process and the surface properties of the latex films were discussed, and the surface free energy of latex films were estimated using two different theoretical models. The emulsion and its films were characterized by particle size distribution (PSD) analysis, transmission electron microscopy (TEM), Fourier transform infrared spectrum (FTIR), nuclear magnetic resonance (¹H‐NMR and ¹⁹F‐NMR) spectrometry, contact angle (CA) and X‐ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), and thermogravimetry (TG) analysis. The results indicate that the average particle size of the latex particles is about 160 nm and the PSD is narrow, the synthesized latex particles exist with core‐shell structure, and a gradient distribution of fluorine and silicon exist in the latex films. In addition, both the hydrophobicity and thermal stability of the latex films are greatly improved because of the enrichment of fluorine and silicon at the film‐air interface, and the surface free energy is as low as 15.4 mN/m, which is comparable to that of polytetrafluoroethylene (PTFE). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

PVA作用下含氟丙烯酸酯共聚乳液的制备与表征

以聚乙烯醇(PVA)为乳化剂,采用Fe2+-H2O2引发体系,以全氟烷基乙基甲基丙烯酸酯(FM)、丙烯酸丁酯(BA)、苯乙烯(St)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)、丙烯酸羟乙酯(HEA)为主要单体进行乳液聚合,制得了阳离子含氟丙烯酸酯多元共聚物乳液。通过FTIR、1HNMR、透射电镜(TEM)、示差扫描量热(DSC)及接触角测试对共聚物结构、乳胶粒径及形态、乳胶膜表面性能进行了研究。结果表明,该乳液的粒子形态呈球形,单分散性良好,平均粒径为90～100nm;随着共聚物中含氟单体质量分数的增加,乳胶膜的表面自由能显著降低;退火处理有助于含氟基团迁移到乳胶膜表面,乳胶膜表面自由能进一步降低。     

可聚合乳化剂合成含氟丙烯酸酯无皂乳液及其性能

以甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）、甲基丙烯酸六氟丁酯（HFMA）等为主要原料,采用预乳化种子乳液聚合法合成了含氟丙烯酸酯无皂乳液,考察了可聚合乳化剂烯丙氧基壬基酚聚氧乙烯（10）醚硫酸铵（DNS-86）和HFMA的用量对无皂乳液的电解质稳定性和涂膜耐水性的影响。利用傅里叶红外光谱、差示量热扫描仪及热重分析对氟丙乳液涂膜进行了表征。结果表明：与传统乳液聚合得到的乳液及相应的涂膜相比,无皂乳液的耐电解质性能和涂膜的耐水性都有一定的提高,含氟单体有效地参与了聚合,涂膜的疏水性大大增强,耐热性显著提高。     

不同偶联剂对苯丙乳液的改性效果

采用核壳乳液聚合法,利用前期研究已确定的核壳乳液合成配方,分别将不同种类和用量的硅烷偶联剂[γ-氨丙基三乙氧基硅烷(KH-550)、γ-(2,3-环氧丙氧)丙基三甲氧基硅烷(KH-560)以及乙烯基三乙氧基硅烷(DL-151)]引入到苯丙乳液中,制得有机硅改性苯丙乳液。利用差示扫描量热分析(DSC)法、透射电镜(TEM)法和粒度分析法等多种检测手段,研究了偶联剂的种类与用量对乳液性能(包括粒径及其分布、钙离子稳定性、黏度、玻璃化转变温度及乳胶粒的核壳结构等)和乳胶膜性能(包括成膜性、吸水率、耐水性、附着力和铅笔硬度等)的影响。结果表明:乳胶粒的平均粒径最小为115 nm;DL-151和KH-560对苯丙乳液的改性效果较好,可以考虑将两者复配后共同改性苯丙乳液,以期获得综合性能较好的改性苯丙乳液。