蓖麻油聚醚多元醇在聚氨酯软泡中的应用

利用双金属催化剂(DMC)制备了相对分子质量在2000～5600之间的聚氨酯(PU)软泡用蓖麻油聚醚多元醇,并通过发泡实验与常用软泡聚醚多元醇H-330进行了性能比较。结果表明,相对分子质量2000的蓖麻油聚醚多元醇制备的泡沫拉伸强度、伸长率和压陷硬度等均优于H-330聚醚,表明蓖麻油聚醚多元醇完全可以取代普通聚醚多元醇用于普通软泡生产。     

蓖麻油和环氧树脂改性水性聚氨酯-丙烯酸酯的合成与表征

以甲苯二异氰酸酯(TD I)、聚醚型多元醇(N210)、2,2-二羟甲基丙酸(DMPA)、甲基丙烯酸甲酯(MMA)等为主要原料,蓖麻油(C.O.)和脂肪族环氧树脂(RE)为交联剂,以原位乳液聚合法制备出聚氨酯-丙烯酸酯(PUA)复合乳液。以无皂乳液聚合法合成了聚丙烯酸酯乳液(PA),再与聚氨酯(PU)乳液机械混合得到PU/PA共混乳液。探讨了蓖麻油C.O.、RE对复合乳液及涂膜性能的影响,烯丙氧基羟丙基磺酸钠(COPS-1)用量对共混乳液和涂膜性能的影响。结果表明,C.O.、RE分别占PU干质量的5.0%～7.0%和2.0%～3.0%,COPS-1占单体总质量的2.0%时,乳液和涂膜综合性能较好。PUA比PU/PA柔韧性好、断裂伸长率高及附着力好,硬度低,成本高。红外光谱分析发现,PUA与PU/PA中—NH—全部形成氢键。TEM观察到,PUA形成核-壳结构的粒子,粒径较小。通过AFM扫描发现,PUA存在硬段与软段的微相分离。     

蓖麻油交联改性阳离子型聚氨酯乳液

以甲苯二异氰酸酯(TDI)、聚乙二醇(PEG)和N-甲基二乙醇胺(MDEA)等为主要原料,以蓖麻油(C.O.)作为部分聚醚多元醇的替代物,采用PU(聚氨酯)预聚体法制备出具有一定交联结构的亲水性阳离子型WPU(水性聚氨酯)乳液。结果表明:当体系交联度较低时,C.O.对WPU的改性效果不明显;当体系交联度较高时,WPU乳液稳定性及其胶膜耐水性等均随C.O.比例增加而提高;当n(PEG)∶n(C.O.)=7∶3时,WPU胶膜的耐水性(吸水率约6%)相对最好,其静态接触角(约82°)相对最大。     

油溶性单组分聚氨酯灌浆材料的研制

以聚醚多元醇、蓖麻油、多亚甲基多苯基多异氰酸酯(PAPI)和助剂等为原料,制得了单组分油溶性聚氨酯(PU)灌浆材料。研究了PU预聚体的配方、反应条件、蓖麻油及增塑剂的用量对该灌浆材料性能的影响。研究结果表明,当蓖麻油用量为混合醇质量的70%时,该灌浆材料所形成的固结物压缩强度较高(为32.5MPa),适用于加固地表和防水兼备的工程。     

高固含量丙烯酸酯改性聚氨酯胶粘剂的研制

以聚醚多元醇、聚酯多元醇和蓖麻油为混合多元醇,以改性MDI(4,4′-二苯基甲烷二异氰酸酯)及PAPI(多亚甲基多苯基多异氰酸酯)为混合异氰酸酯,合成了聚氨酯(PU)胶粘剂预聚体;然后以PA(羟基丙烯酸酯树脂)作为PU预聚体的改性剂,制得高固含量的PUA(聚丙烯酸酯改性聚氨酯)胶粘剂。结果表明:当m(改性MDI)∶m(PAPI)=1∶1、n(-NCO)∶n(-OH)=2.2∶1、w(PA)=8%(相对于PU质量而言)和w(丙烯酸羟乙酯)=3%(相对于PU质量而言)时,PUA胶粘剂的综合性能较好。     

蓖麻油基聚醚多元醇的制备及其表征

以双金属氰化物(DMC)为催化剂、蓖麻油为起始剂制备了新型蓖麻油基聚醚多元醇.采用傅立叶变换红外(FTIR)、核磁共振(1H-NMR)、凝胶色谱(GPc)及热失重(TG)等分析手段对合成产物的结构和热稳定性进行表征.结果表明,蓖麻油基聚醚多元醇结构中既含有蓖麻油的酯基和双键,又含有聚醚的烷基醚基团;本实验的蓖麻油基聚醚多元醇相对分子质量分布随相对分子质量的增大而变窄;与普通聚醚多元醇相比具有更高的热稳定性.     

双固化胶粘剂的制备及性能研究

以MDI(二苯基甲烷二异氰酸酯)、PPG(聚醚二元醇)为主要原料,制备了端—NCO基PU(聚氨酯)预聚体(热固化PU胶粘剂的A组分);然后以蓖麻油基聚酯多元醇、蓖麻油和PNA(聚己二酸新戊二醇酯)为固化剂,采用共混法得到混合多元醇(热固化PU胶粘剂的B组分);随后以Irgacure754和TPO-L为复合光引发剂、PUA(聚氨酯丙烯酸酯)为基体,制得光固化PUA胶粘剂(C组分);最后将上述A组分、B组分和C组分按比例共混后,得到双固化胶粘剂。研究结果表明:该双固化胶粘剂经UV辐照后,其初始剥离强度明显提高;双固化胶粘剂中C=C含量较低,而增加光引发剂掺量能提高该胶粘剂的光固化速率;当m(Irgacure754)∶m(TPO-L)=1∶1、w(复合光引发剂)=6%和w(PUA)=8%~10%(均相对于胶粘剂质量而言)时,双固化胶粘剂的剥离强度较大、综合性能较佳。     

聚醚软段对HMDI基透明聚氨酯弹性体性能的影响

以环己基甲烷二异氰酸酯(HMDI)、聚氧化乙烯二醇(PEG)、聚氧化丙烯二醇(PPG)和聚四氢呋喃醚二醇(PTMG)为主要原料,采用预聚法合成了一系列透明聚氨酯(PU)弹性体。通过红外光谱、热重分析、动态机械性能、拉伸性能和光学性能测试等方法讨论了不同聚醚多元醇组分对所合成的透明PU弹性体的热性能、结晶性能和机械性能的影响。结果表明,相同条件下,PTMG基PU薄膜的热稳定性、软硬段相容性以及力学强度要明显优于PPG基和PEG基PU薄膜;由于软段结晶能力的不同,PPG、PTMG基PU薄膜的透光度和雾度均明显好于PEG基薄膜。     

聚氨酯复鞣填充剂的合成

蓖麻油经马来酸酐酯化得到羟基官能度为2.0～2.2的改性蓖麻油（MCO）,将其作为多元醇成分与异佛尔酮二异氰酸酯（IPDI）、聚乙二醇1000（PEG1000）和二羟甲基丙酸（DMPA）等反应合成脂肪族耐光型聚氨酯复鞣填充剂(CPUF)。重点探讨了MCO/PEG1000、加料顺序、反应温度、DMPA用量和中和剂对乳液稳定性的影响。利用IR对聚氨酯复鞣剂的结构进行了表征。确定了工艺过程：改性蓖麻油首先同IPDI在70 ℃预聚40min,然后加入PEG1000和DMPA在80 ℃扩链100 min生成羟基终端的聚氨酯,其中m(MCO)∶m(PEG1000)=1∶1;中和剂选择三乙胺,聚氨酯复鞣剂中—COOH的质量分数为4%～5%。     

环保无溶剂型双组分聚氨酯结构胶的研制

在传统PU(聚氨酯)胶粘剂组成体系中,以蓖麻油作为PAPI(多亚甲基多苯基异氰酸酯)固化剂的改性剂,并引入芳烃基聚酯多元醇和催化剂等,制备出一种适合工业化生产的环保无溶剂型双组分PU结构胶。研究了固化剂的改性、芳烃基聚酯多元醇类型及含量、无机填料和催化剂含量等对PU结构胶黏度和粘接性能的影响。结果表明:固化剂的适当改性有助于提高PU结构胶的粘接强度;当w[芳烃基聚酯多元醇(样8#)]=18%(相对于B组分质量而言)时,PU结构胶的综合性能相对最好,其剪切强度为10.9 MPa、90°剥离强度为50.2 N/cm;无机物填料的引入虽能降低PU结构胶的生产成本,但也会降低其粘接强度;催化剂的引入能有效提高PU结构胶的固化速率,其含量可根据不同地区、不同季节和不同用途进行调节。     

Insect problems of sunflowers

Many insect pests belonging to several different groups attack cultivated sunflowers in North America. Sunflowers are native to this continent and weeds belonging to the same or closely related species are abundant throughout areas where cultivated sunflowers are grown. Thus, most sunflower insects are native and have been multiplying rapidly during the recent expansion in sunflower production. Discussion of the insect pests of sunflowers is facilitated by grouping them according to the part of the sunflower plant attacked, e.g., (a) leaf feeders, (b) stem and root feeders, and (c) head feeders. Leaf feeders are usually the easiest group to control. They are exposed to view, they and their damage are easily evaluated, and effective insecticidal controls can be applied when necessary. The stem and root feeders such as the carrot beetle in the South and cutworms in the North can cause severe damage before control measures are applied. However, many other species of stem feeders can be present in large numbers without causing economic damage. Head feeders include the sunflower moth, the banded sunflower moths, the sunflower seed maggot, the seed midge, and the seed weevil. These pests are potentially very damaging and, once they have entered the head, are difficult to control with insecticides. Traps baited with a synthetic pheromone are now available to monitor the abundance of sunflower moths. Further research on early warning systems to detect the abundance and distribution of other pests in this group is especially important. These will enable growers to apply controls before the pests are protected within the heads and will reduce the application of insecticides when they are not required.     

智能膜材料研究新进展

能感知和响应外界物理和化学信号的智能膜是仿生功能膜领域的重要技术进展之一,已成为国际上膜科学领域研究的新热点。本文综述了智能膜材料方面的研究新进展,重点介绍了温度响应型、pH响应型、光响应型、葡萄糖浓度响应型以及分子识别响应型等环境刺激响应型智能膜的研究进展。     

Scaling-up of instantaneous data of complex kinetics

Kinetic data related to complex mixtures of reactants and catalysts are necessary to simulate design and rate industrial chemical reactors. In the particular case of Fluidised-bed Catalytic Cracking, the main reaction takes place in riser reactors; whereas laboratory data are obtained in small fixed bed reactors. Even though this important difference in size and hydrodynamics, laboratory reactors are used to estimate, accurately, yield to products and apparent activation energies of the reactions proposed; however estimated frequency factors are very different from the ones observed at industrial reactors. In this work a scaling-up of frequency factors is performed, assuming that activation energies estimated in laboratory are correct. The adjusting effort is minimised because it is necessary to scale-up only one of the reaction rates and the rest of them are fitted proportionally to the first one. A 5-lump kinetic scheme for catalytic cracking of vacuum gas oils is used to test this approach; prediction obtained for industrial yields is very accurate.     

Polymers of phenylenediamines

The chemical or electrochemical oxidation of phenylenediamines in acidic aqueous media yields the corresponding oligomers or polymers. Their structures and properties are discussed in relation to a closely-related conducting polymer, polyaniline. Depending on the reaction conditions, polyphenylenediamines are produced as powders, colloidal dispersions, thin films, or composites. In contrast to polyaniline, polyphenylenediamines are rated as non-conductors and their conductivities are low. Similarly to polyaniline, these polymers display a salt–base transition and they are redox-active. They act as reductants of noble-metal compounds to the corresponding metals or as precursors in the carbonization to nitrogen-rich carbons. Applications proposed in the literature are outlined; they include the corrosion protection of metals, catalysis, electrorheology, sensors, energy-conversion devices, electrochromism, noble-metal recovery, and water treatment.     

茚酮化合物合成方法研究进展

茚酮化合物广泛存在于许多天然产物中,这类化合物具有多种生理活性,是重要的有机合成中间体,广泛应用于医药、农药、染料的合成等。本文重点介绍了环化法合成茚酮化合物,其中分子内傅雷德尔-克瑞福斯（Friedel-Crafts）环化法是茚酮化合物的经典合成法,该法优点是技术成熟,后处理较简单,易于工业化,但该方法产生大量的含铝废液,对环境造成污染。同时,文章对近年来出现的新的茚酮化合物合成方法,如重排法、光化法等进行了对比讨论,新方法与经典合成法相比,具有条件温和、步骤少、产物纯度高等优点,但受到所用原材料等条件的限制,其工业化进程不易实现。通过对近十几年来茚酮化合物合成方法的系统化讨论,指出开发绿色环保、原子经济、易于工业化的新的茚酮化合物合成方法是今后研究的重点。     

Assessment of the wettability of pharmaceutical powders

There is considerable interest in the assessment of the wettability of pharmaceutical powders, as the data can be used to give indications of product performance (in terms of a crude predictor of rates of drug release from dosage forms, or as a guide to the interfacial interactions between components of a formulation). However, contact angle methods for powders are problematic, in particular because powders have heterogeneous and rough surfaces, and these are often capable of rapid changes in properties. The different approaches to contact angle assessment are reviewed, and some advantages of vapour sorption experiments are discused.     

杀虫抗生素的发展概况与展望

杀虫抗生素是生物源杀虫剂,具有高效、低毒、选择性强、对环境无公害等特点,在害虫综合治理中有重要地位,是无公害作物中首选农药之一。作者就杀虫抗生素的品种开发情况进行了阐述,对杀虫素的杀虫机理、抗性机制及进一步加大研究开发力度等问题进行了讨论。     

Exploring the methods of synthesis,functionalization, and characterization of graphene and graphene oxide for supercapacitor applications

Graphene and graphene oxide, are attracting more attention over the last decades in the area of supercapacitor research and researchers concentrate on extensive exploration, owing to their dominating electrical conductivity, combined with mechanical properties. This review is a panoramic approach, giving insights into various aspects related to graphene and graphene oxide such as their properties, production methods, functionalities, and their applications in supercapacitors. The study ought to be beneficial to novice as well as to the domain experts. Various properties of both materials are explored and both synthesis methods are elaborated. Extra emphasis is given to bring out the role of graphene and graphene oxide in promoting the performance of supercapacitors. Synthesis methods are tabulated based on the evaluation metrics like specific capacitance and capacitance retention. Finally, the application of graphene and graphene oxide in supercapacitors are highlighted. Before concluding, perspectives along with challenges for further development are proposed and are expected to facilitate researchers in shedding light on further studies in this explorative area.     

给水生物预处理工艺中生物相的作用

分析了国内现有的给水微生物预处理运行资料,阐述了生物预处理中接触氧化法的机理,讨论了参与生物预处理的微生物的种类及其作用,指出了生物预处理的优缺点及今后应重点解决的问题。     

Characteristics of the storage proteins of cotton

The storage proteins of the cottonseed are composed of α and β globulins which are homologous to the vicilins and legumins, respectively, of the legumes. Gene sequences for members of both protein families have been determined, and the derived amino acid compositions are presented here. The proteolytic cleavages and glycosylations involved in the processing of the preproproteins during embryogenesis to yield the proteins found in the mature seed are outlined.