离心机产生塑化物的原因分析及处理方法

分析了离心机产生塑化物的原因，并提出了具体的处理方法，经过实际运行，达到了生产的使用要求。

氯醋生产中塑化物产生的原因及防范措施

石河子中发化工有限责任公司开发生产的氯醋产品是氯乙烯和醋酸乙烯二元共聚树脂。由于第二单体的引入，该树脂软化温度和熔体粘度较低，加工性能优良，可广泛应用于制造涂料、粘合剂、油墨等。可制得耐候性和耐酸碱性好的制品，同时还是生产半硬质块地板和柔性卷材地板的原料，是一种重要的改性聚氯乙烯树脂。但是由于软化温度降低，产生塑化物的几率远远大于通用性树脂，塑化物的产生影响了树脂的外观和溶解性（加工方面），更影响了成品树脂的质量（杂质），限制了树脂的使用。

聚丙烯粉料中的塑化物是如何产生的

一、前言齐鲁石化公司塑料厂6万t/a聚丙烯装置是引进HIMoNT公司的Spheripol工艺技术,亦是当今比较先进的聚丙烯装置。本装置由华福公司设计,自开车以来运行比较平稳,但也存在着一些问题,如从聚合生产出来的粉料中有塑化物,呈块状或丝状,时多时少,并一直困绕着装置的平稳运行。

Resosolv和氯仿用于牙髓塑化后根管再通的临床研究

目的 比较Resosolv和氯仿再通塑化后根管的能力。方法 4 0颗离体牙 (80个根管 )经FR酚醛树脂塑化后随机分成 4组 ,每组 2 0个根管。A组 :K型锉和Resosolv去除根管内塑化物 ;B组 :K型锉和氯仿去除根管内塑化物 ;C组 :超声K型锉和Resosolv去除根管内塑化物 ;D组 :超声K型锉和氯仿去除根管内塑化物。记录根管通畅的个数、操作时间和工作长度丧失情况。结果 Resosolv溶解根管内塑化物的能力明显优于氯仿 ,Resosolv辅助能通畅 87 5 %的根管 ,而氯仿辅助仅能通畅 4 5 0 %的根管。结论 Resosolv是有效的根管内塑化物的辅助溶剂。

Acetylation of Chinese bamboo flour and thermoplasticity

Chinese bamboo flour was chemically modified by acetylation with acetic anhydride by using trichloroacetic acid as an activation agent and the optimized condition for acetylation of bamboo flour was determined as the trichloroacetic acid amount 6.0 g per 1.5-g bamboo flour, ultrasosonication duration 40 min and the reaction time 1 h at 65℃. The composition, microstructure and thermal behavior of acetylated bamboo flour were preliminarily characterized by FT-IR, DSC and SEM etc. The acetylated bamboo flour can be molded into sheets at 130℃ and 10 MPa, indicating the modified bamboo flour possesses thermalplastic performance.

PVC树脂杂质粒子的产生原因及控制措施

针对PVC产品中出现杂质及塑化物的问题,对整个生产系统进行排查,确定塑化物产生于风送管线,因此采取了在料仓下部、包装线之前加装振动筛,以及更换风送管线的措施。实施后产品中再未出现塑化物。

混凝土技术新进展

混凝土技术发展最突出的表现就是添加高效减水剂制备的"超塑化拌合物",即用水量较低,而流动性还非常好的拌合物,硬化后由于孔隙率小,因而强度高且耐久性优异。为使暴露于侵蚀环境的钢筋混凝土结构寿命长久的目的,运用阻锈剂、环氧涂层钢筋和阴极保护等,也是同期出现,并且已为众所周知的先进技术途径。

Ultrasonic plastification speed of polymer and its influencing factors

The melt filling difficulty in micro cavity is one of the main challenges for micro-injection molding (MIM). An approach employing ultrasound in MIM was proposed. The approach was extensively studied through experiments with a home-made experimental ultrasonic plastification device. The results of the experiments show that polymer ultrasonic plastification speed increases with ultrasonic supply voltage and plastification pressure. When the ultrasonic supply voltage is 200 V and the plastification pressure is 2.0 MPa, the polymer ultrasonic plastification speed reaches the maximum value of 0.111 1 g/s. The results also indicate that the ultrasonic cavitation effect is the most significant effect of all the three effects during polymer ultrasonic plastification process.

Toughening wood/polypropylene composites with polyethylene octene elastomer (POE)

Polyethylene octene elastomer (POE) as impact modifier was incorporated into wood/polypropylene composites (WPC) to enhance the impact strength of the composite. Two extruding routes, i.e. direct extruding route and two-stage extruding route, were adopted to produce Wood Powder/PP/POE ternary composites. The mechanical and dynamic mechanical analysis (DMA) properties of the composites were investigated. The results showed that the addition of POE can increase the impact strength of the composites, and the composites produced via two-stage extruding route showed superior mechanical properties. The results of the DMA confirmed the mechanical tests.

Derivatives of 3（5）,4-Dinitropyrazole as Potential Energetic Plasticisers

The development of a pseudo-one pot synthesis of 3（5）,4-dinitropyrazole enabled us to use it as a starting material for energetic plasticisers. Its acidic proton allowed simple derivatisation on one of the ring nitrogens. The thermal characteristics of two derivatives were evaluated. For instance, the N-allyl compound was a liquid with very low glass transition temperature, whereas the N-propargyl compound was a sticky solid at ambient temperature. The two compounds were both thermally stable according to STANAG 4582.

Discrete dislocation plasticity analysis of dispersion strengthening in oxide dispersion strengthened(ODS) steels

A discrete dislocation plasticity analysis of dispersion strengthening in oxide dispersion strengthened(ODS) steels was described. Parametric dislocation dynamics(PDD) simulation of the interaction between an edge dislocation and randomly distributed spherical dispersoids(Y2O3) in bcc iron was performed for measuring the influence of the dispersoid distribution on the critical resolved shear stress(CRSS). The dispersoid distribution was made using a method mimicking the Ostwald growth mechanism. Then, an edge dislocation was introduced, and was moved under a constant shear stress condition. The CRSS was extracted from the result of dislocation velocity under constant shear stress using the mobility(linear) relationship between the shear stress and the dislocation velocity. The results suggest that the dispersoid distribution gives a significant influence to the CRSS, and the influence of dislocation dipole, which forms just before finishing up the Orowan looping mechanism, is substantial in determining the CRSS, especially for the interaction with small dispersoids. Therefore, the well-known Orowan equation for determining the CRSS cannot give an accurate estimation, because the influence of the dislocation dipole in the process of the Orowan looping mechanism is not accounted for in the equation.

Comparative analysis on homogeneity of Pb and Cd in epoxy molding compounds

Reference materials for quantitative determination of regulated heavy metals, such as Pb and Cd in electronic components, were designed and investigated in terms of stability and homogeneity. Reference materials with two concentration levels of heavy metals were prepared by spiking Pb and Cd compounds to epoxy molding compounds made by mixing silica powders and epoxy resin. The concentration changes of the reference materials during stability test for 1 a were not observed. In the homogeneity assessment, the as-prepared reference materials were studied by using three different analytical tools, inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray fluoroescence spectrometry (XRF) and laser ablation ICP mass. The results show different homogeneities by the characteristics of analytical tools and the materials.

Waste Plastic Conversion into Hydrocarbon Fuel Materials

The increased demand and high price for energy sources are driving efforts to convert organic compounds into useful hydrocarbon fuels. Although much of this work has focused on biomass, there are strong benefits to deriving fuels from waste plastic material. Natural State Research Inc. （NSR） has invented a simple and economically viable process to decompose the hydrocarbon polymers of waste plastic into the shorter chain hydrocarbon of liquid fuel （patent pending）. The method and principle of the production/process will be discussed. Initial tests with several widely used polymers indicate a high potential for commercialization.

Municipal Waste Plastics Conversion into Aviation Fuel

Aviation fuel is in great demand globally. The increased demand and high price for energy sources are driving efforts to convert natural non-renewable organic compounds into useful hydrocarbon fuel materials such as in form of aviation fuel. Alternate sources to these non-renewable hydrocarbon fuels are important and necessary. Much of these alternative sources are focused on biomass however, there are strong benefits of deriving fuels from waste plastic materials. Thermal processes can be used to convert waste plastics into hydrocarbon fuels like aviation fuel, which have unlimited applications in airline industries, as well as in transportation and power generation industries. These thermal processes are used to break down the long carbon chains found in plastics into the shorter chains in a temperature range from 300-450 ℃. This method has been carried out in succession in previous experiments. This simple and economically viable process has been developed to convert the hydrocarbon polymers of waste plastics into the short and medium chain hydrocarbons of liquid fuels. Based on the initial characterization, a fractionated portion of the developed fuel shows properties similar to some of the commercially available aviation fuels.

Generation of Transportation Fuel from Solid Municipal Waste Plastics

Transportation fuels derived from imported fossil fuels are subjected to the price fluctuations of the global marketplace, and constitute a major expense in the operation of a vehicle. Emissions from the evaporation and combustion of these fuels contribute to a range of environmental and health problems, causing poor air quality and emitting greenhouse gases that contribute to global warming. Alternative fuel created from domestic sources has been proposed as a solution to these problems, and many fuels are being developed based on biomass and other renewable sources. Natural State Research, Inc. proposes a different alternative hydrocarbon fuel which is produced from abundant waste plastic materials. This fuel burns more efficiently and cleaner than commercial gasoline and diesel. The process exists to efficiently convert waste plastic into a reliable low cost source of fuel.

Climate change and contrasting plasticity in timing of a two-step migration episode of an Arctic-nesting avian herbivore

Greenland white-fronted geese Anser albifrons flavirostris wintering in Britain and Ireland migrate over the sea for 700-1200 km to stage 3-5 weeks in Iceland in spring, continuing a similar distance over the sea and Greenland Ice Cap to West Greenland breeding grounds. During 1969 to 2012, the geese advanced the mean departure date from Ireland by 15 days, during which time also they attained threshold fat stores earlier as well as departing in fatter condition. Over that period, Iceland spring-staging geese shifted from consuming underground plant storage organs to grazing managed hayfields, which provide fresh grass growth despite sub-zero temperatures, when traditional natural foods are inaccessible in frozen substrates. In 2012 and 2013, geese arrived three weeks earlier to Iceland, in fatter condition and accumulated fat significantly slower than in 1997-1999 and 2007. Although geese accumulated sufficient fat stores earlier in Iceland in 2007, 2012 and 2013, they departed around the same date as in 1997-1999, prolonging spring staging by three weeks. Plasticity in winter departure dates is likely due to improved winter feeding conditions （enabling earlier departure in better condition） and a novel predictable food resource in Iceland. Greenland white-fronted geese attained threshold fat stores in Iceland earlier, but remained rather than departing earlier to Greenland. Despite arriving earlier in Iceland, arrival dates on the breeding areas have not changed since the 1880s, presumably because of relatively constant cool springs and heavy snowfall in West Greenland during recent years [Current Zoology 60 （2）： 233-242, 2014].

Effects of soil nitrogen levels on growth and defense of the native and introduced genotypes of alligator weed

Plants growing in nutrient-rich environment are predicted to be less defended than conspecifics under nutrient limitation.However,less is known about the effects of nutrient levels on tolerance and induced resistance,and whether the effects differ between native and introduced populations of invasive plants.We performed a greenhouse experiment with introduced(the USA)and native(Argentina)genotypes of Alternanthera philoxeroides in order to study the effects of soil nitrogen levels on plant growth,constitutive and herbivore(Agasicles hygrophila)-induced chemical defense,and herbivory tolerance.We measured total biomass,elongation rate(as proxy of growth rate),carbon and nitrogen,and the concentration of triterpenoid saponins(defensive chemicals)in leaves and roots.Constitutive resistance(+33%higher leaf triterpenoid saponins in control treatment at low nitrogen level)and tolerance[less decreased total biomass after herbivory treatment(−24%and−15%for high and low nitrogen levels)]were favored at lower nitrogen level,while induced resistance was favored at higher nitrogen level(+24%increased leaf triterpenoid saponins after herbivory treatment at high nitrogen level).Constitutive resistance and tolerance exhibited trade-offs with growth rate,while induced resistance positively correlated with growth rate.Additionally,the introduced genotypes had−6%lower content of leaf carbon in the presence of herbivores than the native genotypes at low nitrogen level,but such difference was absent at high nitrogen level.Our results indicate that soil nitrogen levels influence the preference of different defensive strategies of plant,and interweave with herbivory to determine the performance of introduced genotypes.