内交联水性聚氨酯脲的制备及性能表征

以二羟甲基丙酸(DMPA)、异佛尔酮二异氰酸酯(IPDI)、乙二胺作为硬段,聚醚多元醇(GE220)为软段,以蓖麻油(CA)和三羟甲基丙烷(TMP)多元醇为内交联剂,制备了两个系列的交联型水性聚氨酯脲(PUU)分散液,测定了PUU水分散液及其膜的物理性能和力学性能.结果表明,与未交联的PUU水分散液相比,交联型PUU表现出较好的疏水性能,吸水率从52.4%下降到12.0%,力学性能也有较大程度的提高.随交联剂用量的增加,尽管水分散液的粒径略有增加,但成膜后的耐水性增强,力学性能提高.     

超支化聚酯-酰胺/聚氨酯水分散体制备及成膜性能研究

将聚氨酯预聚体接枝到以季戊四醇为核,二羟甲基丙酸、二异丙醇胺、六氢苯酐为单体的超支化聚酯-酰胺上,得到了聚氨酯/超支化聚酯-酰胺(PU-HP)杂化水分散体。采用了IR、SEM和化学滴定等方法对产物进行了表征和分析。试验表明超支化聚氨酯水分散体的粒径约50nm,在水中有良好的分散性和稳定性;以S-100水性固化剂可以制得耐水性较好的涂膜,同时具有良好的成膜性和物理性能;并确定了S-100的用量为树脂用量的30%。     

Effect of polydimethylsiloxane macrodiol molecular weight on properties and morphology of polyurethane and polyurethaneurea

Two series of polyurethanes and polyurethaneureas were prepared using a two‐step bulk‐solution polymerization procedure. Each series consisted of three polymers based on three molecular weights of α,ω‐bis(6‐hydroxyethoxypropyl) polydimethylsiloxane (PDMS): 940, 1913, and 2955. The soft segment in all cases was an 80:20 mixture of PDMS and poly(hexamethylene oxide) (MW 700), and the hard segment was based on 4,4′‐methylenediphenyl diisocyanate and mixed chain extenders (40 wt %). In the polyurethane (PU) series the chain extender was a 60:40 (mol) mixture of BDO and 1,3‐bis(4‐hydroxybutyl)1,1,3,3‐tetramethyldisiloxane (BHTD), whereas in the polyurethaneurea (PUU) series it was a 60:40 (mol) mixture of BHTD and 1,2‐ethylenediamine. The polymerization was carried out by preparing a prepolymer using a bulk polymerization procedure followed by chain extension in a solution of N,N‐dimethylacetamide. Polymers were characterized by size‐exclusion chromatography, tensile testing, differential scanning calorimetry (DSC), and dynamic mechanical thermal analysis (DMTA). The number‐average molecular weights of the polymers in the PU series were in the range of 114,300–124,500, whereas they were in the 78,400–103,300 range for the PUU series. Polymers with good clarity and mechanical properties were obtained with PDMS‐940 and PDMS‐1913, but those obtained from PDMS‐2955, despite having good tensile strength, had a low percentage of elongation, high modulus, and poor clarity. DSC and DMTA results indicated that regardless of the PDMS molecular weight, the siloxane segments existed as a highly phase‐separated state. This poor compatibility was consistent with the low solubility of PDMS compared to that of the hard‐segment‐forming components. The polymers in the polyurethane series exhibited multiple melting endotherms, attributed to the melting of ordered domains from different hard segments. The combined heats of fusion were similar for the materials in the PU series. In contrast, the polymers in the PUU series showed a hard‐segment order that was significantly less defined, with the heat of fusion approximately a third to a half that of the materials in the polyurethane series. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1565–1573, 2003     

负离子型聚氨酯离聚体水分散过程的相反转

用异佛尔酮二异氰酸酯、聚己二酸新戊二醇酯和二羟甲基丙酸（DMPA）合成了负离子型聚氨酯离聚体．研究了该类离聚体在水分散过程中的相反转变化,讨论了DMPA质量分数和水分散温度对相反转过程的影响。结果表明,DMPA质量分数增加或水分散温度提高,可使相反转所需的时间缩短,分散液粒子粒径变小,粒径分布更均匀,黏度增大。水分散温度的作用较DMPA更为明显。差示扫描量热分析表明,水分散过程破坏了亲水性硬链段的有序性。傅里叶变换红外光谱分析表明,聚氨酯水分散液用乙二胺扩链后．脲羰基的氢键化程度随DMPA质量分数的增加、水分散温度的提高而提高。     

Flow patterns and oil—water dispersion in a 0.38 m diameter oscillatory baffled column

We report our experimental flow visualization observations of flow patterns and experimental oil‐water dispersion measurements in an oscillatory baffled column (OBC) of an internal diameter 380 mm. Both types of experiments were carried out covering an identical range of oscillation frequencies, amplitudes, orifice diameters and baffle spacings. The flow visualization observations show that eddy mixing has been achieved in the pilot OBC and the intensity of which is largely dependent on the operational and geometrical parameters tested, which is similar to that in a smaller scale OBC. The scale‐up correlation was found to be linear. The oil‐water dispersion measurements show that the degree of the dispersion depends significantly on the oscillation frequency and amplitude with an increase in either leading to an increase in dispersion. The effect of the orifice diameter on the oil—water dispersion is also evident, but the effect of the baffle spacing is much weaker. Based on the experimental data we have established a correlation relating the degree of oil—water dispersion to the power input to the system. We have also compared the power requirement to achieve a complete dispersion in the pilot OBC with that in a bench scale OBC of 50 mm diameter and found that the energy dissipation is more economical in the large scale application.     

纳米氧化锆在水中分散性研究

鉴于粉体分散对无机膜制备具有重要意义,研究了添加不同分散剂及其加入量对纳米氧化锆粉在水中的分散性,以及分散性与溶液pH值的关系。结果表明:悬浮液的分散性能受到分散剂及其加入量和pH值的影响,不同的分散剂在各自的加入范围内有其最佳加入量。通过对粒径和zeta电位分析,考察含分散剂时pH值对纳米氧化锆粉的分散性能,从中优选最佳pH值的范围。     

油对常用水稳剂缓蚀阻垢和分散性能的影响

采用电导法考察循环水中柴油对阻垢剂阻垢性能的影响,并进一步研究含油水对缓蚀剂的缓蚀能力和分散剂分散氧化铁能力的影响.结果表明,工业循环水中含有柴油对水质稳定剂的性能有很大影响,柴油使缓蚀剂、阻垢剂、分散剂的效能均降低.     

The influence of water on size of the monodisperse polystyrene microspheres prepared by dispersion polymerization

Polystyrene microspheres with uniform sizes have a wide range of applications in biomedical engineering. However, detailed and systematic investigations on the influence of water content on alcohol/water systems are relatively scarce. In this study, the impact of trace water content on microsphere size was comprehensively examined, and a systematic exploration of the varying effects of different hydration levels on particle nucleation and growth mechanisms was conducted. When the water content increased from 0.1% to 0.4%, the microsphere diameter rapidly decreases from 3.6 to 2.71 μm. Correspondingly, the molecular weight increased from 29,797 to 69,186. However, within the water content range of 0.5%–14.5%, alterations in water content induced only slight variations in the microsphere diameter. The microsphere size, molecular weight, conversion rate, and reaction rate were compared in two stages. It was observed that the diminishing influence of water on the system was due to the changes in the main polymerization sites. Subsequently, the addition of water content up to 33.5% revealed an exponential decrease in the microsphere size with increasing water content in ethanol. This pattern was also observed in methanol and isopropanol, demonstrating its universality and predictability, making it applicable for precise prediction of microsphere size in different solvents.     

Formation of monodisperse polyacrylamide particles by dispersion polymerization: particle size and size distribution

Highly monodisperse polyacrylamide microparticles were directly prepared by dispersion polymerization in aqueous alcoholic media initiated by 2,2′‐azobisisobutyronitrile using poly(N‐vinylpyrrolidone) as a steric stabilizer. Monomer conversion was studied dilatometrically and polymer molecular weight was determined viscometrically. The hydrodynamic diameter of polymer particles and its distribution were measured with a dynamic laser light scattering spectrometer. The number of the nuclei produced in the early stage of the polymerization was found to be constant during the remainder of the polymerization. The influences of various polymerization parameters, such as initiator concentration, monomer concentration, stabilizer content, medium polarity, and polymerization temperature on the particle size and size distribution were systematically investigated. Copyright © 2003 Society of Chemical Industry     

纳米ATO水性分散液的制备及其分散稳定性研究

采用球磨法制备了3种纳米锑掺杂二氧化锡(简称ATO)水性分散液,包括未加分散剂,以非离子型高分子分散剂改性和以阴离子分散剂与非离子高分子分散剂复合改性3种情况,并通过Zeta电位仪、激光粒度仪、透射电镜、静止沉降实验等测试方法对纳米ATO水性分散液的稳定性进行了表征.结果发现,ATO纳米颗粒通过分散剂复合改性后,其水性分散液的稳定性最佳,当阴离子分散剂与非离子高分子分散剂的质量比为1∶2,复合分散剂用量为ATO粉体质量的6%时,所得ATO水性分散液的稳定性最好.     

一体化锅炉水处理剂的制备及性能研究

利用自制SW-56共聚物，复配有机磷酸盐和焦亚硫酸钠除氧剂及消泡剂，成功制备XF-4一体化锅炉水处理剂。对XF-4锅炉水处理剂的阻垢、缓蚀进行了试验研究，表明其具有优良的阻垢能力，可以明显抑制热水锅炉积垢现象；加入改性除氧剂能降低锅炉水中溶解氧的含量，使腐蚀控制较理想；配方中的消泡剂组分可防止锅炉水表面起泡，抑制高悬浮物下的携带作用。     

国产水分散型助分散剂在氯乙烯聚合中的应用

通过对国内外各种助分散剂的应用对比,针对PVC生产中存在的问题,在油溶性PVA生产技术基础上,添加VAC共聚单体,研制开发出一种水分散型助分散剂,其各项性能达到国外同类产品水平,现已工业化生产,应用于国内部分PVC厂家。     

纳米二氧化钛—乙二醇分散体系的制备及性能

采用不同分散工艺制备了纳米二氧化钛—乙二醇分散体系 ,对于分散系中粒子的表面电位 ,表面处理前后二氧化钛表面性质的变化 ,以及分散系的流变行为进行了研究     

Crosslinking of pressure sensitive adhesive based on water‐borne acrylate

This publication shows how the kind of crosslinking agents and their contents influence important properties of acrylic based pressure‐sensitive adhesive (PSA) dispersions such as tack, adhesion and cohesion. Synthesized PSAs based on acrylic polymers, containing 2‐ethylhexyl acrylate, butyl acrylate, vinyl acetate, styrene and acrylic acid are used in the preparation of self‐adhesive dispersions used as coating of polyethylene foams and poly(vinyl chloride) and polyester foils. © 2003 Society of Chemical Industry     

染料共价改性石墨烯及其水分散性研究

本文以石墨粉为原料，以直接灰D为改性剂，将其重氮化后共价接枝到自制的还原氧化石墨烯（rGO）上，制备改性石墨烯（MG），以提高石墨烯在水中的分散性，使其更适用于纺织品整理。采用拉曼光谱（Raman）、傅立叶红外光谱（FTIR）、高分辨X射线光电子能谱（XPS）、热重分析（TGA）等表征手段对得到的改性石墨烯进行表征。结果表明，染料分子成功接枝到石墨烯上，接枝率达到21%左右。采用紫外-可见分光光度计（UV-vis）考察了改性石墨烯在水中的分散性。结果发现，相对rGO，MG在水中的分散性和稳定性都大大提高，其水溶液的最大饱和度达到0.185 mg/mL，静置7天后，仍可达到0.092 mg/mL。改性后的石墨烯同时具备了染料和石墨烯的性能。     

Synthesis and characterization of emulsion‐type curing agent of water‐borne epoxy resin

Self‐emulsified water‐borne epoxy curing agent of nonionic type was prepared using triethylene tetramine (TETA) and derivative of epoxy resin as a capping agent, which was synthesized by liquid epoxy resin (E51) and polyethylene glycol (PEG), and the curing agent possessed emulsification and curing properties at the same time. The curing agent with good property of emulsifying liquid epoxy resin could be obtained under the condition of the molar ratio of PEG : E51 : TETA as 0.8 : 1 : 3.5 at 80°C for 5 h. The mean particle size of the emulsion liquid was about 220 nm with the prepared curing agent and epoxy resin at the mass ratio of 1 : 3. The structure of the emulsion‐type curing agent was confirmed by FTIR and ¹H NMR spectra, and the mechanism of cured film formation was also analyzed by SEM photographs. The cured film prepared by the emulsion‐type curing agent and epoxy resin under ambient cure conditions showed good properties even at high staving temperature. This study provides useful suggestions for the application of the water‐borne epoxy resins in coating industry. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2652–2659, 2013     

SMA的合成及其对香精的分散和微胶囊制备的影响

使用溶液聚合法合成苯乙烯-马来酸酐共聚物（SMA）,利用盐化的苯乙烯-马来酸钠盐作为保护胶体分散香精,采用原位聚合法制备三聚氰胺甲醛树脂香精油微胶囊。探究了不同分子量的SMA钠盐对香精的分散作用和对香精油微胶囊制备的影响,并与进口SMA 520对香精的分散作用和微胶囊制备效果进行了对比。实验发现,随着SMA分子量减小,香精油趋向于以较小粒径的液滴分散在连续相中,粒径分布逐渐变窄,香精油滴的分散稳定性提高。当使用的SMA钠盐溶液（质量分数10%）黏度≥145mPa·s时,可制备出粒径为5～20μm,形态为球形、表面有少许凹陷、壳层厚度较为均匀的微胶囊。当使用的SMA钠盐溶液（质量分数10%）的黏度≤67mPa·s时,只能形成极少数的球形微胶囊。作为保护胶体制备香精油微胶囊,进口SMA 520与实验室制备的黏度为314mPa·s的SMA钠盐溶液（质量分数10%）具备相似的效果。     

纳米TiO_2水分散体系稳定性的研究

研究了不同类型的分散剂对金红石型纳米TiO2在水中分散体系稳定性,探讨了分散剂、偶联剂用量、纳米TiO2浓度及pH值对纳米TiO2水分散体系的影响。结果表明,最佳分散剂为SK-5040,最佳分散条件为:100 mL纳米TiO2水溶液中,最佳分散剂用量为1.0 g,KH-570硅烷偶联剂用量为1.5 mL,纳米TiO2浓度为1.0%,pH值为10。     

聚丙烯酰胺水分散乳液的制备及污泥脱水性能研究

通过丙烯酰胺(AM)与甲基丙烯酰氧乙基三甲基氯化铵(DMC)的分散聚合制得阳离子聚丙烯酰胺(CPAM)水分散乳液,通过红外光谱(FT-IR)、核磁共振(1HNMR)、光学显微镜分析了产物的结构与形成机理,并用自制CPAM对污泥脱水效果进行了评定。结果表明,当CPAM质量分数为0.15%,投加量为湿泥总量0.005%～0.01%,污泥pH为3～7时,上清液浊度去除率达96%,滤饼含水率降至68%。