Factors Influencing Droplet Size of Silicone Oil Emulsion with High Solid Content

A silicone oil emulsion with 60% of solid content was prepared with methyl silicone oil used as the main material by means of the emulsifier-in-oil method.The influence of emulsification conditions on the droplet diameter of silicone oil emulsion was discussed.The experimental results showed that the emulsification method,including the quantity of the emulsifier,the time and temperature of emulsification,the emulsifying water dosage,and the stirring speed,had significant impact on the droplet size.The optimal conditions were identified to achieve a smallest droplet diameter of the emulsion at an emulsifier dosage of 6%,an emulsification temperature of 70 ℃,an emulsification time of 30 min,and a stirring speed of 1100 r/min,with water added in two portions at a ratio of 1:1.The high-solid content silicone oil emulsion with a mean droplet diameter of 2.731 μm was prepared under these conditions that could ensure absence of stratification and floating oil under centrifuging at a speed of 3000 r/min for 30 min.

Cationic CO_(2)-based Waterborne Polyurethane with High Solid Content and Excellent Ageing Resistance

High solid content CO_(2)-based cationic waterborne polyurethanes(CWPUs)were prepared using CO_(2)-polyols as soft segment and Nmethyl diethanolamine(MDEA)as hydrophilic group.The resulting stable aqueous dispersion displayed a high solid content of 52%with a low MDEA loading of 3.52 wt%.This novel structural CWPU can provide excellent adhesive strength,whose T-peel strength could reach 173.48N/5cm,20%higher than that of ester-based cationic waterborne polyurethane(87.55 N/5cm).The CO_(2)-based CWPU film showed only 2 wt%swelling percentage after 240 min immersion in water,and no change was observed during its immersion in 5 wt%sodium hydroxide solution.The tensile strength of CO_(2)-WPUs dropped slowly to 91.2%after 480 min immersion in a 5 wt%sodium hydroxide solution,whereas that of esterbased CWPUs dropped quickly to 32%after 240 min and their mechanical properties were lost after 360 min immersion.Meanwhile,the retention of the tensile strength of the CO_(2)-CWPUs was 81.5%even after 720 min immersion in 10 wt%H_(2)O_(2) solution,while it was only ca.38%for the ester-based CWPUs.These results indicated that the cationic CO_(2)-based CWPU may be promising waterborne adhesive with outstanding ageing resistance due to its synergistic effect from carbonate and ether groups of CO_(2)-polyol structure.

High Solids-Content Nanosize Polymeric Microlatexes Made by Microemulsion Copolymerization at Ambient Temperature

The microemulsion copolymerizations of acrylic acid (AA),acrylamide (AM),N-methylol acrylamide (NMA),methylmethacrylate (MMA),butyl acrylate (BA) and acrylonitrile (AN) initiated by the redox initiator ammonium persulfate (APS) and N,N,N′,N′-tetramethylethylenediamine (TMEDA) at ambient temperature were investigated.With this process high solids-content (44.0 wt%) and small (less than 50 nm) particle diameter copolymer latexes were attained.The effects of surfactants,the mechanical stabilities and application properties as an environmentally friendly self-crosslinking pigment printing binder with multifunctional groups were studied.

Nonionic Polymerizable Emulsifier in High-Solids-Content Acrylate Emulsion Polymerization

Stable high-solids-content acrylate emulsion were obtained with a nonionic polymerizable emulsifier allyloxy nonylphenoxy poly （ethyleneoxy） （10） ether （ANPEO10）, and a conventional emulsifier OP-10 as a reference sample. 1H NMR proves that the polymerizable emulsifier ANPEO10 has been incorporated into the resulted acrylate polymers. TEM demonstrates that there are some differences in the particle morphologies. AFM proves that the polymerizable emulsifier ANPEO10 migrating to the surface of the emulsion film was much less than the conventional emulsifier OP-10. The polymerizable emulsifier ANPEO10 can enhance the adhesion with glass plate compared to the conventional emulsifier. Furthermore, with increasing amount of emulsifier, the surface free energy of the films first decreased and then increased, and the adhesion with glass plate is initially enhanced and then attenuated. The water-resistance and solvent-resistance of the films prepared by the polymerizable emulsifier ANPEO10 are superior to those prepared by the conventional emulsifier OP-10.

Biodrying of municipal solid waste with high water content by combined hydrolytic-aerobic technology

The high water content of municipal solid waste(MSW)will reduce the effciency of mechanical sorting,consequently unfavorable for beneficial utilization.In this study,a combined hydrolytic-aerobic biodrying technology was introduced to remove water from MSW.The total water removals were proved to depend on the ventilation frequency and the temporal span in the hydrolytic stage. The ventilation frequency of 6 times/d was preferable in the hydrolytic stage.The hydrolytic span should not be prolonged more than ...

SEED SEMICONTINUOUS EMULSION MULTI-COPOLYMERIZATION OF (METH) ACRYLATES WITH HIGH-SOLID CONTENT: EFFECT OF THE OPERATION CONDITIONS

The seeded semicontinuous emulsion multi-copolymerization of butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), methyl methacrylate (MMA), 2-hydroxyl propyl acrylate (HOPA) and acrylic acid (AA) was used to prepare the acrylic latexes with high-solid content. The effects of monomer emulsion feed rates (R(a)) and (R/E)(E) values, the ratio of emulsifier amount between the initial charge (R) and the addition monomer emulsion (E), on the polymerization reaction features, the viscosities, surface tensions,particle sizes and particle sizes distributions of latexes, T-g and the insoluble fractions of films, the 180 degrees peel strength, tack and holding power of pressure-sensitive adhesive (PSA) tapes, prepared from the latexes, were studied. Experimental study shows that the grafting and crosslinking fraction in the PSA tapes must be controlled within a suitable range to keep the balance of the 180 degrees peel strength, tack and holding power.

Engineering properties for high kitchen waste content municipal solid waste

Engineering properties of municipal solid waste （MSW） depend largely on the waste＇s initial compositionand degree of degradation. MSWs in developing countries usually have a high kitchen waste content（called HKWC MSW）. After comparing and analyzing the laboratory and field test results of physicalcomposition, hydraulic properties, gas generation and gas permeability, and mechanical properties forHKWC MSW and low kitchen waste content MSW （called LKWC MSW）, the following findings wereobtained： （1） HKWC MSW has a higher initial water content （IWC） than LKWC MSW, but the field capacitiesof decomposed HKWC and LKWC MSWs are similar; （2） the hydraulic conductivity and gaspermeability for HKWC MSW are both an order of magnitude smaller than those for LKWC MSW; （3）compared with LKWC MSW, HKWC MSW has a higher landfill gas （LFG） generation rate but a shorterduration and a lower potential capacity; （4） the primary compression feature for decomposed HKWCMSW is similar to that of decomposed LKWC MSW, but the compression induced by degradation ofHKWC MSW is greater than that of LKWC MSW; and （5） the shear strength of HKWC MSW changessignificantly with time and strain. Based on the differences of engineering properties between these twokinds of MSWs, the geo-environmental issues in HKWC MSW landfills were analyzed, including highleachate production, high leachate mounds, low LFG collection efficiency, large settlement and slopestability problem, and corresponding advice for the management and design of HKWC MSW landfills wasrecommended.

水基凝胶注模用高固相含量氧化锆增韧氧化铝陶瓷浆料及烧结陶瓷的性能

在不同氧化锆质量分数(25.0%,27.5%,30.0%)和分散剂添加量(0.2%~0.4%,质量分数)下制备高固相含量(45%~57%,体积分数)、不同pH(1~12)的氧化锆增韧氧化铝(ZTA)陶瓷浆料,研究了pH、分散剂添加量和固相含量等对陶瓷浆料流变性能的影响;在较佳pH和分散剂添加量下制备不同氧化锆含量的陶瓷浆料,经水基凝胶注模成型后,在1600℃进行常压烧结,测试了烧结陶瓷的相对密度和力学性能。结果表明:当pH为7~12时,ZTA陶瓷浆料的Zeta电位和黏度均随pH的增大先减小后增加,且当pH为9时Zeta电位绝对值最大、黏度最小,说明此时陶瓷浆料最为稳定;随着分散剂添加量增加,浆料黏度先减小后增大;随着固相含量增加,浆料黏度增大;在pH为9、分散剂质量分数为0.3%条件下,制备的高固相含量(45%~55%)ZTA陶瓷浆料具有良好的流动性和较低黏度,成型并烧结后,当固相含量较高时,陶瓷的相对密度、抗弯强度和断裂韧度均较高。

高固含量热固性固体推进剂3D打印技术

3D打印技术相比于传统的固体推进剂浇注成型方法具有更高的制造灵活性和安全性。对于高固含量(质量分数大于85%)的固体推进剂材料,传统挤出打印方式存在挤出不连续、成型质量差等问题,限制了发动机的整体性能。针对上述问题,基于超声减摩辅助挤出原理设计了双超声振子共振挤出高固含量热固性固体推进剂打印头。重点探究了打印过程中打印温度、挤出压力、喷嘴直径等关键工艺参数对于打印推进剂材料孔隙率的影响。在打印温度为70℃、挤出压力为0.6 MPa、喷嘴直径为φ1.7 mm,打印层高间距比为0.8的最优工艺参数条件组合下,可打印制备固含量为88%、孔隙率为3.46%、打印制造误差被控制在0.4%以内的复杂变燃速热固性固体推进剂药柱结构,同时打印样件的拉伸强度较传统浇注样件提升56%,为复杂高固含量固体推进剂药柱结构的制造提供了一个新思路。

高固含低黏度生物基氟碳树脂的合成及性能

将生物基原料氢化松香醇与三乙胺、对羟基苯甲醚、丙烯酰氯反应制备了可聚合的丙烯酸氢化松香醇酯,然后其与一系列丙烯酸及其衍生物通过共聚,制备了高固含低黏度生物基氟碳树脂。结合分子动力学模拟,分析了丙烯酸氢化松香醇酯降黏机理,探究了生物基氟碳树脂成膜后的涂膜性能。结果表明,随着丙烯酸氢化松香醇酯质量分数的增加,改性氟碳树脂运动黏度降低;当丙烯酸氢化松香醇酯质量分数为18.6%时,改性氟碳树脂固含量为78.56%,其运动黏度与石油树脂叔碳酸乙烯酯改性氟碳树脂相当,远低于不含大体积侧基的改性氟碳树脂;与叔碳酸乙烯酯相比,丙烯酸氢化松香醇酯的空间体积更大,侧基体积效应更明显,分子间作用力小,降黏效果好;丙烯酸氢化松香醇酯改性氟碳涂膜硬度、附着力高于叔碳酸乙烯酯改性氟碳涂膜,耐化学腐蚀性略低于叔碳酸乙烯酯改性氟碳涂膜。

大掺量固废混凝土的制备及性能研究

将粉煤灰、矿粉、不同类型的钢渣粉按不同质量比(mF∶mK∶mG分别为60∶32∶8、60∶28∶12、60∶24∶16、50∶40∶10、50∶35∶15、50∶30∶20)制备了三元复合掺合料,确定了最佳钢渣粉类型和mF∶mK∶mG。在此基础上,通过调整砂率、水胶比、减水剂掺量等方式制备了大掺量固废混凝土(固废总量≥70%),研究了其工作性、力学及耐久性能。结果表明:综合考虑胶砂流动度、三元复合掺合料的活性指数、经济性和环境效益,推荐选用原状钢渣粉,并控制mF∶mK∶mG为60∶32∶8;制备的大掺量固废混凝土的工作性、力学及耐久性能均较好,满足相关设计要求,并推荐采用聚羧酸减水剂,不推荐采用以萘系减水剂与脂肪族减水剂复配而成的复合减水剂。

SPE-HPLC-UV法测定绞股蓝提取物中皂苷的含量

本试验旨在建立固相萃取-高效液相色谱-紫外检测法(SPE-HPLC-UV)对绞股蓝提取物中绞股蓝皂苷XLIX和皂苷A进行定量分析。样品经甲醇提取,采用C_(18)固相萃取柱净化,使用Kinetex C_(18)色谱柱(150 mm×4.6 mm,2.6μm)分离,流动相乙腈/水,柱温40℃,检测波长203 nm。依照此法测定绞股蓝粗提物中三萜皂苷XLIX和皂苷A的含量。结果表明:2种绞股蓝皂苷在一定质量浓度范围内线性关系良好(r≥0.999),平均回收率为91.38%~98.4%,相对标准偏差为0.69%~2.48%。该方法的灵敏度、准确度和精密度均符合检测技术要求,且简便快速,适用于绞股蓝提取物中绞股蓝皂苷XLIX和皂苷A含量的准确测定。

高球形度超高镍三元前驱体合成因素的研究

探讨不同的搅拌频率、不同的固含量对三元前驱体合成因素的影响,通过共沉淀反应过程中梯次降低搅拌频率和调控反应过程中浆料的固含量,制备了高球形度、高振实密度、粒度分布适中的超高镍三元前驱体Ni_(0.95)Co_(0.04)Mn_(0.01)(OH)_(2)。结果表明:以38 Hz开机,然后以每12 h下调3 Hz的速度梯次降低搅拌频率至20 Hz,并且将固含量控制在300 g/L,既可以保证高球形度、高振实密度,减少球粘连,又可以避免前驱体产生裂纹和碎球,制备出了高球形度、颗粒分布均匀的超高镍三元前驱体。

高含水钻井固废超细颗粒过滤分离实验研究

针对钻井固废处理的难点在于其含有大量10μm以下的超细颗粒难以分离问题,结合振动筛分和深层过滤处理方法,从减少整体固相含量和分离超细颗粒出发,开发了一种能有效去除高含水钻井固废中超细颗粒的新型处理方法。结果表明,在优选工艺参数下,高含水钻井固废经过振动筛分处理后,10μm以上的较大颗粒被去除,固相含量从30.42%降低至9.55%。筛下液再经过深层过滤处理,92.77%的超细颗粒被去除。研究结果表明,新型处理方法对高含水钻井固废超细颗粒有良好的去除效果,有利于实现高含水钻井固废回收利用要求。

高固含量乳化沥青储存稳定性影响因素研究

探究乳化剂掺量、乳化液pH、沥青温度、剪切时间对高固含量乳化沥青储存稳定性的影响。结果表明,各因素均可提高储存稳定性,随乳化剂掺量增加,乳化沥青稳定性呈现先增加后保持稳定趋势;随乳化液pH、沥青温度、剪切时间的增加,乳化沥青稳定性呈现先升高后降低趋势。乳化沥青制备工艺的最佳条件为pH值2.7,沥青温度139℃,剪切时间83 s。

低黏度高固含量聚醋酸乙烯酯乳液胶黏剂的制备及应用

聚醋酸乙烯酯(PVAc)具有固化速度快、初粘性好的优点,可作为胶黏剂或增稠剂应用于人造板工业。研究以醋酸乙烯酯(VAc)为单体、聚乙烯醇(PVA)为保护胶体,采用半连续乳液聚合法制备低黏度、高固含量聚醋酸乙烯酯乳液,并考察了PVA种类及其他聚合工艺因素对乳液性能的影响。结果表明:PVA种类对乳液性能影响较大。采用激光粒度分析仪、差示扫描量热仪(DSC)等对不同种类PVA合成的乳液进行表征表明:粒径随PVA醇解度增加而明显增大;PVA聚合度对乳液的玻璃化转变温度(Tg)影响较大。以PVA0599为保护胶体制备的PVAc乳液作为木材胶黏剂时,其拉伸剪切强度达8.62 MPa。

不同后扩链剂对无溶剂型高固含水基聚氨酯的影响

分别以水、乙二胺(EDA)、异佛尔酮二胺(IPDA)、二乙烯三胺(DETA)、N-β-(氨乙基)-γ-氨丙基甲基二甲氧基硅烷(KH-602)和聚醚胺(D-230)为后扩链剂,制备一系列无溶剂高固含水基聚氨酯,研究不同后扩链剂对水基聚氨酯的乳液性能(乳液稳定性、粒径大小、乳液黏度)、成膜性能(耐水耐溶剂性、力学性能、热稳定性、玻璃化转变温度)及应用性能(常温耐折牢度、热粘性、耐温性)的影响。结果表明,在较高R值(—NCO/—OH摩尔比)条件下,采用后扩链法可制备无溶剂、高固含水基聚氨酯,其热力学性能满足应用需求。其中,含环状结构的后扩链剂如IPDA可提高聚氨酯力学性能和耐温性;含交联功能的后扩链剂如DETA与KH602可提高聚氨酯耐水耐溶剂性及涂层抗热粘性和耐温性;而含柔性链的后扩链剂如D-230所制备的聚氨酯具有非常低的模量,适合制备非常柔软的聚氨酯。

高固含量水性聚氨酯的研究进展

从乳化工艺、亲水单体、异氰酸酯指数(R值)和软段等方面综述了水性聚氨酯(WPU)固含量的影响因素,并对高固含量WPU的发展趋势进行了展望。

环保型高固含低表面处理容忍性环氧涂层的制备及其性能

为了满足钢结构设备表面的维修需要,制备了高固含低表面处理容忍性环氧涂层,并分别讨论了树脂含量、固化剂种类以及复配颜填料对于所制备涂层性能的影响。结果表明:采用最优配方(A组分中环氧树脂质量分数为25%,改性曼尼希碱为固化剂,磷酸锌、氧化锌、三聚磷酸铝、钼酸锌、复合铁钛粉复配体系为颜填料)制备的涂料具有较好的流动性和润湿性,在低表面处理基材上即可使用,成膜后涂层的防腐蚀性能优异。

基于DPM模型的碱回收炉竹浆黑液雾化数值模拟研究

为高效回收高固含量竹浆黑液的化学品和热能,改善其雾化性能,本研究采用DPM(discrete phase model)模拟研究碱回收炉中高固含量竹浆黑液的雾化性能。通过建立的碱回收炉三维几何模型,采用Fluent软件对碱回收炉进行冷态流场模拟,研究了黑液黏度、雾化锥角及粒径范围对碱回收炉中黑液雾化效果、颗粒分布、熔融物垫层形成的影响。结果表明,增大黑液黏度对液滴破碎影响显著,而对于分散沉降的影响远不及雾化锥角及初始液滴尺寸;碱回收炉前墙上、下二次风之间区域存在结渣风险。液滴粒径大于0.5 mm时,黑液液滴主要受重力作用下沉至垫层,能有效减少气流的机械携带现象。