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嵌段型非离子表面活性剂在微乳剂制备中的应用 总被引:5,自引:0,他引:5
介绍了1组嵌段型非离子表面活性剂的合成方法,进行了一系列性质表征,筛选出一种用于新型高效农药5.2%甲维盐·溴虫腈微乳剂的制备。考察了表面活性剂、助表面活性剂、溶剂及水对其稳定性的影响,确定了优惠配方。对甘蓝小菜蛾幼虫的室内毒力测定及田间药效结果表明,共毒系数CTC为172.5,具有明显的增效作用。将其稀释1000、2000倍7d后的防效分别为90.4%及80.5%,均高于0.5%甲维盐乳油、10%溴虫腈悬浮剂2种单剂药效。显示了该药剂具有较强的杀虫作用和较长的持效期,具有较好的推广应用前景。 相似文献
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Modification of polypropylene (PP) has been successfully carried out by graft copolymerization of gelatin, by chemical method using benzoyl peroxide (BPO) as radical initiator. PP was preirradiated by gamma rays at a constant dose rate of 3.40 kGy/h before grafting to introduce hydroperoxide groups. Optimum conditions pertaining to maximum percentage of grafting were evaluated as a function of different reaction parameters. Maximum percentage of grafting of gelatin (115%) was obtained at BPO concentration = 4.132 × 10?2 mol/L in 120 min at 70°C using 30 mL of water. Characterization of PP‐g‐gelatin was carried out through FTIR, thermogravimetric analysis, and scanning electron microscopy. Swelling studies were carried out in pure, binary, ternary, and quaternary solvent systems comprising distilled water, ethanol, dimethylsulphoxide (DMSO), and N,N‐dimethylformamide (DMF) in different ratios. Maximum swelling of PP‐g‐gelatin (both composite and true graft) was observed in pure solvents that is, DMSO followed by DMF, ethanol, and water and was higher than that observed in the mixed solvent system. Water retention studies of unmodified PP, that is, pristine PP and PP‐g‐gelatin (both composite and true graft) were investigated at different time periods, temperatures and pH. Maximum % water retention for PP‐g‐gelatin (composite; 170%) was observed in 8 h at 50°C in neutral medium (pH = 7). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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以丙烯酸羟乙酯(HEA)、丙烯腈(AN)为单体,偶氮二异丁腈(AIBN)为引发剂,β-巯基乙醇(β-ME)为链转移剂在甲醇溶剂中通过自由基聚合,制备了HEA-AN共聚物。用红外光谱(FT-1 1IR)、H核磁共振(H-NMR)以及热重分析(TG)对聚合物的结构进行了分析表征。通过控制变量的方法研究了反应温度、时间、引发剂用量、链转移剂用量等对聚合反应中的黏均分子质量、转化率的影响;对比分析了一次投料和连续投料2种方法合成的共聚物的羟值,发现连续投料法合成的聚合物在反应过程中羟值变化很小,合成的聚合物结构组成均匀性更好。 相似文献
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Massarat B. S. Osman El Sayed A. Hegazy Abo El-Khair B. Mostafa Afaf M. Abdel-Maksoud 《Polymer International》1995,36(1):47-56
Graft copolymers were obtained by radiation-induced grafting of vinyl acetate (VAc) and N-vinylpyrrolidone (NVP) individually and in binary mixture on to polypropylene (PP) films. The effect of some grafting conditions on the grafting yield was determined. The addition of Cu2Cl2 as inhibitor to the reaction medium inhibited the homopolymerization of the comonomer. The grafting process was remarkably enhanced by using dioxan as a diluent compared with other solvents used. The addition of some inorganic salts has a great influence on the individual grafting of both monomers. The gel percent in the graft copolymer was determined; it increased as the grafting yield increased. The swelling behaviour and electrical conductivity for the grafted films slightly increased by grafting. The changes in thermal parameters such as glass transition (Tg), melting (Tm) and recrystallization (Trc) temperatures and heats of melting (ΔHm) and recrystallization (ΔHrc) of the graft copolymers were also followed by differential scanning calorimetry (DSC). These thermal parameters of PP were varied by grafting with VAc and NVP and depend on the graft yield, which reflects the change in its crystalline domains and formation of crosslinks in the graft chains. The heat of recrystallization of the graft copolymer by cooling from the molten state decreases by grafting which is a good indication of crosslink formation, since crosslinking decreases the crystallizability of the polymer matrix. 相似文献
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Nanoscale bimetallic particles (Pd/Fe, Pd/Zn, Pt/Fe, Ni/Fe) have been synthesized in the laboratory for treatment of chlorinated organic pollutants. Specific surface areas of the nanoscale particles are tens of times larger than those of commercially available microscale metal particles. Rapid and complete dechlorination of several chlorinated organic solvents and chlorinated aromatic compounds was achieved by using the nanoscale bimetallic particles. Evidence observed suggests that within the bimetallic complex, one metal (Fe, Zn) serves primarily as electron donor while the other as catalyst (Pd, Pt). Surface-area-normalized reactivity constants are about 100 times higher than those of microscale iron particles. Production of chlorinated byproducts, frequently reported in studies with iron particles, is notably reduced due to the presence of catalyst. The nano-particle technology offers great opportunities for both fundamental research and technological applications in environmental engineering and science. 相似文献
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Graft copolymerization of starch has been carried out onto preirradiated polypropylene (PP) in an aqueous medium using benzoyl peroxide (BPO) as the radical initiator. The maximum percentage of grafting (115%) of starch onto PP was obtained at optimum conditions of BPO concentration, 1.239 × 10−3 moles; temperature, 65°C; in 120 min. using 30 mL of water. Swelling studies were carried out in pure, binary, ternary and quaternary solvent systems comprising of water, ethanol (EtOH), dimethylsulphoxide (DMSO), and N,N‐dimethylformamide (DMF) in different ratios. Maximum swelling is observed in DMSO and DMF, followed by EtOH and least in water for true graft. Water retention studies of pristine PP and PP‐g‐Starch (both composite and true graft) were investigated at different time periods, temperature and pH. The composite contains grafted PP, unreacted starch and unreacted PP whereas true graft is the product from which both unreacted polymers have been removed. Maximum % water retention of PP‐g‐Starch (composite) (110%) was observed in 8 h at 50°C in neutral medium (pH = 7). The graft copolymers were characterized by FTIR, DTG, DTA, TGA, and SEM. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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非离子型水分散性聚氨酯的制备及性能研究 总被引:5,自引:0,他引:5
主要讨论了以聚乙二醇为亲水单体,聚醚多元醇N220为多元醇制备非离子水性聚氨酯乳液。讨论了亲水单体的用量,NCO与OH比例对聚氨酯乳液及干膜性能的影响。并比较了阴离子型,阳离子型和非离子型聚氨酯乳液的性能。 相似文献
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Copolymers of linear low‐density polyethylene (LLDPE) grafted with two novel nonionic surfactants, acrylic glycerol monostearate ester (AGMS) and acrylic polyoxyethylenesorbitan monooleate ester (ATWEEN80), containing hydrophilic and hydrophobic groups and 1‐olefin double bond were prepared by using a plasticorder at 190°C. To evaluate the grafting degree, two different approaches based on 1H‐NMR data were proposed, and FTIR calibration was showed to validate these methods. The rheological response of the molten polymers, determined under dynamic shear flow at small‐amplitude oscillations, indicated that crosslinking formation of the chains could be decreased with increasing the monomer concentration. Their thermal behavior was studied by DSC and polarization microscope (PLM): The crystallization temperature (TC) of grafted LLDPE shifted to higher temperature compared with neat LLDPE because the grafted chains acted as nucleating agents. Water and glycerol were used to calculate the surface free energy of grafted LLDPE films. The results indicated that the novel polyoxyethylene surfactant ATWEEN80 could greatly improve the hydrophilicity of LLDPE and the surface free energy varied from 33 mN/m of neat LLDPE to 106 mN/m of the grafted LLDPE film. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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Qi Meng Yiwen Cao Shufeng Ma Meiling Wang Hao Niu Weihua Jiang Qiaoqiao Teng Ninghong Jia 《应用聚合物科学杂志》2023,140(6):e53433
Organic acid is a kind of important fine chemicals with wide application, while impropriate discharges would cause serious damage to environment. In this report, two polyethyleneimine (PEI-600, 1800) functionalized polystyrene (PS) resins were facilely prepared to remediate common organic acids. The heavier PEI-1800 resulted in surprisingly lower nitrogen loading of PSPEI under optimal conditions due to more significant extra grafting. Therefore, PSPEI-600 was used to adsorb two groups (aliphatic and aromatic) of eight common organic acids, and showed highest adsorptive capacities toward salicylic acid (SA) and trifluoroacetic acid (TFA). The adsorption of TFA was faster and was mainly due to strong acid–base interactions by forming ammonium carboxylate. SA possessed lower acidity, but its additional π-π stacking and hydrogen bonding interactions with the PSPEI resin led to a slower but overall higher uptake. Kinetic studies indicated that both acid adsorptions conformed to pseudo-second-order kinetics, and the adsorption rate was controlled by intraparticle diffusion. The adsorptions followed Langmuir isotherms and were identified as a spontaneous endothermic process. 相似文献
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High yield and pure zinc glutarate catalysts used for copolymerization of carbon dioxide and propylene oxide have been synthesized in different solvents by ultrasonic methodology. For the purposes of comparison, low‐yield zinc glutarates were also synthesized via mechanical stirring method with other synthetic conditions remaining unchanged. Fourier Transform Infrared Spectroscopy and wide‐angle X‐ray diffraction techniques confirmed the presence of high‐quality zinc glutarate catalysts. Accordingly, poly(propylene carbonate) (PPC) can be synthesized from carbon dioxide and propylene oxide using the zinc glutarate catalysts. It was confirmed that the as‐prepared PPC had an alternating copolymer structure together with high molecular weight. The thermal and mechanical properties of the obtained PPC copolymer were determined by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and tensile test. DSC and TGA results showed that the PPC copolymer exhibited high glass transition temperature (39.39°C) and decomposition temperature (278°C) when compared to their corresponding values reported in the literature. Tensile test showed that the PPC film exhibited superior mechanical strength. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2327–2334, 2002 相似文献
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C. K. V. Zainul Abid Sruti Chattopadhyay Nasreen Mazumdar Harpal Singh 《应用聚合物科学杂志》2010,116(3):1640-1649
Quaternary ammonium compounds are some of the most widely used antimicrobial agents for various medical applications due to their low toxicity and broad spectrum antimicrobial activity. Various generations of poly(ethyleneglycol)diacrylate (PEGDA) based dendrimers were synthesized by Michael addition reaction of PEGDA with ethylene diamine and diethyl amine. The percentage yield of different generation of dendrimers were 70%, 66%, 60%, and 85% for G1.0 (=), G1.5 (NH2), G2.0 (=), and G2.5 (=, NEt2), respectively. Synthesized dendrimers were also copolymerized with ethyleneglycol dimethacrylate by free radical bulk polymerization at room temperature using ammonium persulphate/N,N,N′,N′‐tetramethyl ethylenediamine as a redox initiator system to form dendritic copolymer networks. These networks were quaternized with hydrochloric acid by continuously refluxing at 40°C for 6 h. Dendrimers and quaternized dendritic copolymer networks were characterized by 1HNMR, FTIR, Differential scanning calorimetry, Thermogravimetric analysis, Scanning electron microscope, swelling, and leaching studies. Synthesized quaternary ammonium dendritic copolymer networks were found to be biostable and insoluble in water and capable of killing both Gram‐positive and Gram‐negative bacteria when contaminated water was treated with them. It was also observed that antimicrobial efficiency of dendritic copolymer networks increases with the increase in nitrogen atoms in the copolymer. The dendritic copolymer network with 16 quaternary ammonium groups (G2.5 (=, NEt2): EGDMA QHCl) were highly efficient to disinfect 10 mL bacterial solution of 2000 cfu/mL within 2 min even at a very low concentration of 0.005 g/mL. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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Tahia B. Mostafa 《应用聚合物科学杂志》2009,111(1):11-18
The chemical modification of polypropylene (PP) fibers by graft copolymerization with vinylimidazole (VIm) and acrylonitrile (AN) was carried out using γ‐radiation. Preparation conditions, such as irradiation dose, comonomer concentration and composition and type of solvent, affecting the degree of grafting were investigated. The suitable diluent for obtaining reasonable graft VIm/AN copolymer yield was acetone. The higher grafted yield was achieved by increasing the amount of vinylimidazole in comonomer feed solution as well as irradiation dose. The derivatives of PP‐g‐P(VIm/AN) grafted fibers of different functional groups were obtained by treating the grafted fibers with various organic reagents containing reactive amino groups, such as sulpha‐drug compounds, aliphatic‐ and aromatic amines. Characterization of the obtained graft copolymers and their chemical treatments with different amines was also investigated. It was observed that the nitrile group in PP‐g‐P(VIm/AN) polymer undergoes simple addition reaction via nucleophilic interaction mechanism to produce the corresponding PP‐graft‐P(vinylimidazole/acrylomidine) derivatives. The ability of the grafted fibers and their treated forms to absorb some metal ions as Cd, Hg, and Pb from their individual and mixture solutions was evaluated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009. 相似文献
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污水生物处理过程中很多较强毒害作用的有机污染物转移到活性污泥中,进而影响了污泥的土地利用。本文依据对生态环境及人类健康的影响,以7种受关注度比较高的典型新兴有机污染物为对象,综述了其在污泥中的赋存状况,同时对这些污染物可能对污泥土地利用产生的影响进行了分析。最后,对7种新兴有机污染物在污泥中的赋存状况进行了总结,并对相关研究方向进行了展望,指出应继续分析和监测污泥中有机污染物,尤其是新兴有机污染物对生态环境的影响和危害,并深入研究污泥中这些物质的有效降解途径与方法,使污泥能够安全地进行土地利用。 相似文献