KLM型立式螺旋搅拌磨机在铜镍矿中的应用

介绍了立式螺旋搅拌磨机的基本结构和工作原理,重点描述了KLM型立式螺旋搅拌磨机用于通化吉恩镍业选矿厂铜镍矿再磨作业中的应用概况。铜镍分离的给矿粒度由原来的-38μm占65.25%(-74μm占90%)提高到91.33%,矿石单体解离度进一步提高,为铜镍高效分离提供了良好的浮选环境。在原矿中铜品位仅提高0.001%的条件下,铜精矿产品中铜品位提高1.683%,铜理论回收率提高1.08%,而铜精矿产品中镍品位降低0.583%,降幅高达27.87%,较好地实现了铜镍分离的目的;而在原矿中镍品位减小0.02%的情况下,镍精矿产品中镍品位降低0.122%,镍理论回收率提高0.14%。立式螺旋搅拌磨机是一种适合于有色金属矿细磨与再磨,且性能优越的磨矿设备。     

甲基丙烯酸酯类含硅有机单体的制备及其光固化

以甲基丙烯酸羟乙酯、γ-甲基丙烯酰氧基丙基三甲氧基硅烷为原料,在乙醇钠催化下进行酯化反应,合成了可以进行紫外光固化的多官能度甲基丙烯酸酯类含硅有机单体混合物(MAE-Si-OCH_3),并通过傅里叶红外光谱和核磁共振氢谱(~1H-NMR)对其结构进行了表征。通过~1H-NMR确定了甲基丙烯酸酯基团,含硅基团和甲氧基的比例关系。以2,4,6-三甲基苯甲酰基-二苯基氧化膦为光引发剂,考察了MAE-Si-OCH_3在405 nm LED光源下的自由基光固化行为。测试了MAE-Si-OCH_3的耐酸耐碱性和硬度。研究发现,所制备的甲基丙烯酸酯类含硅有机单体可以有效地进行自由基光固化,并且具有较好的耐酸碱性和一定的硬度。     

On the mechanisms of cyclic and bicyclic fatty acid monomer formation in heated edible oils

Using recent literature data reporting definite chemical structures for cyclic fatty acid monomers (CFAM), we present new insights into cyclization and rearrangement mechanisms that may be involved in the formation of CFAM and their further transformation into bicyclic fatty acid monomers (BFAM) during the frying process. The existence of structural similarities between CFAM and the unsaturated fatty acids from which they were formed, and between structurally related BFAM and CFAM, led us to examine various possible concerted reactions and thermal rearrangements. These structural similarities as well as the limited number of isomers formed provide evidence for concerted routes that are concordant with all identified structures formed from oleic, linoleic and linolenic acids. The proposed reaction pathways account for the presence of BFAM as well as their most probable structures.     

Eutectic‐forming binary system of poly(ethylene oxide) and p‐hydroxybenzaldehyde

The binary system consisting of poly(ethylene oxide) (PEO) and p‐hydroxybenzaldehyde (PHD) was characterized with the aid of differential scanning calorimetry, polarized optical microscopy, scanning electron microscopy and Fourier‐transform infrared spectroscopy. The phase diagram created from thermal analysis data provides clear evidence for the presence of a eutectic at 35.5 °C and PHD weight fraction of 42%. Microscopy studies show that, for the mixtures with a PHD weight fraction below 42%, the resulting morphology of the crystallized sample is coarse spherulitic texture. In the case of eutectic composition, the crystallization of the binary melt produces degenerated homogenous spherulites. For the hypoeutectic PEO–PHD mixtures, the PHD crystals become large and thick with decreasing the PEO fraction. Moreover, the infrared measurements indicate that hydrogen bonding in the PEO–PHD binary system has an important effect on the PEO helical conformation. With increase of the amount of PHD component, the PEO helical conformation in the PEO–PHD mixtures changes from the 7₂ helix to the 10₃ helix. Further increase of the PHD content leads to the destruction of the PEO helical conformation. Copyright © 2003 Society of Chemical Industry     

Initiator‐fragment incorporation radical polymerization of ethylene glycol dimethacrylate in the presence of 1,1‐diphenylethylene: synthesis and characterization of soluble hyperbranched polymer nanoparticles

The polymerization of ethylene glycol dimethacrylate (EGDMA) as crosslinker was carried out at 70 and 80 °C in benzene using dimethyl 2,2′‐azobisisobutyrate (MAIB) as initiator at concentrations as high as 0.50–0.70 mol l^?1 in the presence of 1,1‐diphenylethylene (DPE), where the concentrations of EGDMA and DPE were 0.50–0.70 and 0.25–0.50 mol l^?1, respectively. The polymerization proceeded homogeneously, without gelation, to give soluble polymers. The yield and molecular weight of the resulting polymers increased with time. The homogeneous polymerization system involved ESR‐observable DPE‐derived radicals of considerably high concentration (3.6–5.3 × 10^?5 mol l^?1). The methoxycarbonylpropyl groups as MAIB‐fragments were incorporated as a main constituent (35–50 mol%) into the polymers (initiator‐fragment incorporation radical polymerization). The polymers also contained DPE units (15 mol%) and EGDMA units with double bonds (10–25 mol%) and without double bonds (20 mol%). Results from gel permeation chromatography (GPC)–multiangle laser light scattering (MALLS), transmission electron microscopy (TEM) and viscometric measurements revealed that the individual polymer molecules were formed as hyperbranched nanoparticles. Copyright © 2004 Society of Chemical Industry     

Formation of a soluble hyperbranched polymer via initiator–fragment incorporation radical copolymerization of divinyl adipate and isobutyl vinyl ether

The copolymerization of divinyl adipate (DVA) with isobutyl vinyl ether (IBVE) was conducted at 70 and 80 °C in benzene using azobisisobutyronitrile (AIBN), at a concentration as high as 0.50 mol l^?1 as the initiator, where the concentrations of DVA and IBVE were 0.40 and 0.60 mol l^?1, respectively. The copolymerization proceeded homogeneously, without any gelation, to yield soluble copolymers in spite of the high molar ratio of DVA as an excellent cross‐linker for IBVE. The copolymer yield increased with time, and the number‐average molecular weight (M_n = 0.9–2.4 × 10⁴ g mol^?1) from gel permeation chromatography (GPC) and molecular weight distribution (M_w/M_n = 1.5–7.6) of the resulting copolymer increased with copolymer yield. The cyanopropyl group, as a fragment of AIBN, was incorporated as a main constituent in the copolymer, the fraction of which increased from ca 10 to ca 20 % with copolymer yield, hence indicating that the copolymerization is an initiator–fragment incorporation radical polymerization. The copolymers also contained IBVE units (10–30 %) and DVA units with intact double bond (8–36 %) and without double bond (45 %). The intrinsic viscosity of the copolymer was very low (0.1 dl g^?1) at 30 °C in tetrahydrofuran. The results from GPC–multi‐angle laser light scattering (MALLS), transmission electron microscopy (TEM) and MALLS revealed that individual copolymer molecules were formed as hyperbranched nanoparticles. Copyright © 2004 Society of Chemical Industry     

聚丙烯双单体接枝体系研究

以过氧化二异丙苯／过氧化二苯甲酰引发体系引发制备了各种聚丙烯的双单体接枝物，并对这些接枝物进行各种性能测试，确定了最佳的接枝单体组合、组成和工艺条件。     

Functional peroxides and peroxy oligoesters on the basis of pyromellitic dianhydride

A series of peroxy oligomers has been synthesized on the basis of pyromellitic dianhydride and tetrachloroanhydride of pyromellitic acid by condensation with polyethylene glycols and tert-butylhydroperoxide. The resulting oligoesters contain two types of functional groups: carboxylic – which can participate in ionic reactions and peroxide – able to initiate certain radical processes. Concentrations of these groups depend on the method of synthesis, the nature of starting monomers, and the molecular mass of polyethylene glycol. Structures of oligoesters have been determined by IR and ¹H-NMR spectroscopy. The oligoesters are able to form three-dimensional networks when heated to 400 K. A mechanism of the network formation is proposed. These materials can be used as curing agents for unsaturated polyesters and also for epoxy + unsaturated polyester resin compositions. Electronic Publication     

彩色油性铸型尼龙的加工应用技术

介绍了彩色油性铸型尼龙的加工应用技术，用此技术生产的尼龙制品强度高，耐腐蚀，耐磨，耐热，并具有较高的自润滑性及彩色外观。     

Synthesis and properties of fluorinated polyimides and fluorinated poly(imide amide)s containing pendent cyano groups

A series of fluorinated polyimides and fluorinated poly(imide amide)s containing pendent cyano groups were prepared and investigated to determine their dielectric constants as a function of relative humidity and thermal characteristics. The fluorinated polymides and fluorinated poly(imide amide)s containing pendent cyano groups were prepared by reaction of bis(4-aminophenoxy) benzonitriles with a fluorinated dianhydride and with a fluorinated di(acid chloride) containing preformed imide rings. The properties of the fluorinated polyimides and fluorinated poly(imide amide)s containing pendent cyano groups were compared with those of fluorinated polyimides and fluorinated poly(imide amide)s prepared from 1,3-bis(4-aminophenoxy)benzene. The introduction of the pendent cyano groups caused an increase in the dielectric constant and an increase in the glass transition temperature of the polymers compared with the polymers prepared without pendent cyano groups.