Fluorine is the most negative-electronic element,So negative charges gathered around fluorine atoms and electron cloud covered densely in polymers. That the neighboring fluorine atoms repel mutually make the fluorine atoms which connect with the main chain of the fluorine-containing polymers spiral-shaped distribution along the zigzag carbon-carbon chain. The radius of fluorine atom is extremely small,so the main chain protected well. The fluorine-carbon bond of the fluorine-containing polymer is short so the bond energy is very big. The polarizability of fluorine atom is low. Therefore,the fluorine-containing polymers have many special performances such as the thermo stability,the chemical stability and the weather-resistant,the low surface energy,the non-adherence,chemistry corrosiveness resistant,the water-repellency, and so on.The fluorine-containing acrylate was synthesized by hexafluoropropylene trimer,HEMA and other monomers on the condition of tri-ethylamine (NEt3)’s existence in this thesis. The fluorine-containing emulsion was copolymerized with this special fluorine-containing acrylate, BA, MMA, AA. The Fluorine-containing emulsion was stable. And the stability of this emulsion and the film’s water-repellency are researched.With tri-ethylamine (NEt3)’s existence,was synthesized by directly mixed-reaction of C9F18 and HEMA. In this process, this is no solvent.
Biosurfactant is a high surface-active agent synthesized by plant, animal or microorganism, but at present the mosts come from the microorganism production.Compared with chemical surfactant, has environment compatibility, saying non-toxic, be completely degraded by microorganism, not create pollution to environment, good selectivity and few use level. Biosurfactant has been gradually applied in agriculture, , food drink, industry clean, leather, papermaking, petroleum, environmental fields and so on. Many biosurfactants and their producing processes have been studied deeply and widely. However, so far few of biosurfactants have been industrialized for its low-yield and high costs. So is the only way for the industrialization to extensively screen the strains and to analyze the producing processes and to study the relevance between the molecular structure and its function. Therefore, more biosurfactants of specific purpose and high function should be produced by the way of structural and simulating. And is necessary to optimize the producing conditions and purification methods. Therefore, much integrated technology and other science such as simulation technology, nano-technology and bio-technology, is bound to the development of the overall trend.A large number of biosurfactant-producing strains have been reported. But the microbes on Earth are very rich so that less than 1% of microorganisms have been known. So there is still a lot of undiscovered species. In the paper, three biosurfactant-producing strains were screened from the organic pesticides activated sludge by designing filter medium. All of them are identified to belong to genera of Acinetobacter. From them, W2 with its surfactant has the best performance. So the factors for fermentation of surfactant were studied, and the fermentation condition was optimized initially..At the same time, the microbiology and molecular biotechnology has been developed, so that the process of microbial fermentation and the molecular mechanism of metabolic regulation have been deeply studies and are more and more clear. So more genetically engineered bacterial with high performance may be constructed with genetic analysis and molecular biotechnology, which is necessary for industrialization. In the paper the of Strain W2 was studied by the way of the elimination of bacterial plasmid and rapid detective technology. It was found that there is a big plasmid at least through electrophoresis test. The strains with plasmid can produce macrophages oil spot (that is to producing surfactant), but the strains with eliminated plasmid can not produce oil spot macrophages (that is to producing no surfactant). It is concluded that the is lactated among the plasmid.
Ultraviolet (UV)-Curable waterborne polyurethane acrylate resins have gained more and more atention and speedy development in the past years as result of the merits in environmental protection, lower energy consumption and excellent propertie. The most of them are based on the single hydroxyl-terminated acrylate, therefore, only very limited content of double bonds can be incorporated into the polyurethane backbones, as well as, the water resistance and thermal resistance of the polyurethane based on polyester polyol and polyether polyol are very poor. The hydrodiol containingcan be incorporated into the polyurethane backbones reacted with diisocyanate to crosslink, and the instead of polyester polyol and polyether polyol was incorporated into the polyurethane backbones, the properties of the coating can be improved because of the water resistance and thermal resistance. The related reports of this are spare.The novel prepolymer containing more double bonds and carboxyl group were prepared from 1,1,1-trimethylolpropane (TMP)-based diol which was synthesized by TMP and maleic anhydride (MA), toluene-2, 4-diisocyanate (TDI) and 2-hydroxyethyl acrylate (2-HEA). The control processes of the synthesis was determined by N, N-dibutylamine reverse-titrate method and FT-IR.In-situ Fourier transform Infrared spectroscopy was employed to investigate the of noncatalyzed of the polycondensation process between toluene-2, 4-diisocyanate (TDI) and polyethers diol. These studies showed that when the reaction was divided into two phases, a reasonable fit of the reaction profile could be approved with the second order rate equation for every phase firstly. The constants at different phases were obtained and then the activation energies were also obtained.A series of the waterborne polyurethane acrylate resins were obtained based on the different kinds of and diisocyanate (NCO). These studies on properties of resins showed that: the system of uv-curable waterborne resins was stable emulsion when the content of carboxyl group was 0.2-0.6 mmol/g, the size of particles in emulsion was minished obviously when the content of carboxyl group was increased, as well as the viscosity was increased. The appearance of the system was changed from unstable emulsion with little yellow to unstable ivory-white emulsion with little blue ligh with the increase of neutralization. Studies on properties of showed that: neutralized with triethylamine, degree of neutralization was 80%, Darocur 1173 as the photoinitiator with the dosage 2% in prepolymer.
Investigation on Diffusional Behavior of Water-Insoluble Chain Transfer Agents in Emulsion Polymerization
Chain Transfer Agents (CTAs), as a sort of effective reagent for regulating the molecular weight and molecular weight distributions (MWDs) of polymers, is widely used in the industrial production behavior. However, the effect of CTAs can be exerted only if the entry of CTAs into the major loci of emulsion polymerization, polymer particles, is successfully achieved. Sois necessary to investigate the of CTAs, especially the water-insoluble CTAs in the emulsion polymerization.In the article, the emulsion containing polymer particles was first prepared by batch emulsion polymerization, then the solution of monomer and CTA was added to implement the emulsion polymerization, and the difrusional behavior of water-insoluble dodecyl-mercaptan was discussed, in contrast with the one got from the experiment of water-soluble amyl-mercaptan.The model proposed by Momura shows that the diffusion of CTA in emulsion polymerization is realized by its passing through monomer droplet/water/polymer particles. By combining the analysis on the data of our experiment, is obvious to find that the amyl-mercaptan diffused fast through the water phase due to its good solubility in water while the diffusion of dodecyl-mercaptan was affected by the mass transfer resistance in the water phase, due to its water insolubility. Further study also indicates that elevation of temperature and enlargement of the interface could improve the diffusional ability of CTAs in heterogeneous system.
As a kind of engaged device, twin screw extruder has been gained widespread availability, for its extremely excellent attribute for processing, and twin screw extruder has became the main tendency of market development. Drive system is one of the key part of twin screw extruder, which requires a large torque for output and can endure large axial force. But due to the confining or restricting of center distance, the design and manufacture of the gears, shafts and bearings etc., become more difficult.This paper makes many profound researches onof twin screw extruder. Based on introduce of the researching achievements both in home and abroad, the current situation and future development of of twin screw extruder, a detailed analysis and comparison is put on the and thrust bearing group. Then combined with the design request, a general scheme and thrust bearing design and layout scheme is selected. Then drive system and its accessories design and analysis are accomplished. In this part design and selection of accessories of drive system, calculation of profile modified gears, strengh check of output shaft and calculation of bearing’s service life are all involved. Especially, analysis of the coordination of each accessorie of drive system , uniform load structure and gear engaged rigidity are specified involved, also. At last, By using ANSYS 11.0, the finite element analysis of the strain and stress to the key output shaft B in the drive system is completed, and gained the pictures and results of the analysis of the strain and stress status. According to the pictures and results, proper improvements and mpdifications are put forward, in order to improve the proformance of the drive system and increase its server lifeThe researches of this paper can play an important role in the development of the drive system of twin screw extruder and can supply optimized scheme and technical support for maintenance of the drive system. is a good reference on design and development of like devices.
Study on United Production of Propionic Acid and Vitamins B12 by Removal of Propionic Acid from Fermentation Broth
Fermentation production of propionic acid（PA）and vitamin B12(VB12)is greatly inhibited by propionic acid that is product of fermentation.By the removal of propionate acid,high concentration of propionic acid and VB12 was obtained.In this thesis,PA has been separated by.Adsorption behaviors and the selectivity were studied by using static methods including the static equilibrium ,the thermo dynamics properties and the kinetics of adsorption.The good operation conditions including adsorption,washing,desorption and regeneration,have been confirmed by dynamic adsorption methods.Then PA has been separated from the fermentation broth.PA was separated by expanded bed was preliminary studied.The adsorbent ZGA330 was selected to separate PA from the residual solution of fermentation.The adsorbent selectivity is good,which the selectivity coefficient（K）of PA with amino acids and glucose in turn equaled to 0.025 g·L-1and 22.9 g·L-1.The dynamic adsorption experiments indicated that the best flow rate was 3BV·h--1;the fitting washing condition:at first wash out 2.0 BV at 3BV·h-1;the good desorption condition:flow rate of desorption was 3BV·h-1,the concentration of NaOH solution was 1.0mol·L-1,the volume of desorption solution was 2.5BV.Based on study of fixed bed,that PA was separated by expanded bed was preliminary studied.The dynamic adsorption experiments indicated that the best expanded volume was 2BV;the fitting washing condition:at first wash out 5.0 BV with 2BV of expanded volume;the good desorption condition: flow rate of desorption was 3BV·h-1,the concentration of NaOH solution was 1.0mol·L-1,the volume ofdesorption solution was 2.5BVBy the secondary removal of PA with fixed bed of ZGA330,high concentration of VB12was obtained comparing to the batch fermentation. VB12concentration was 0.55 fold of those in the batch fermentation respectively.By the once removal of PA with expanded bed of ZGA330,high concentration of VB12was obtained comparing to the batch fermentation. VB12concentration was 0.51 fold of those in the batch fermentation respectively.
Using duck blood and NaNO2 as main material, theof was studied. Effects of various factors on the of the pigment were discussed, and main factors were optimized. And then the stability and rheological properties of pigment were also studied, is benefit for further research. The results showed as follows.1. The method of acetone to determine the content of can exclude the interference of impurities during response action and could reflect the amount of pigment production more accurately.2. The synthesis conditions of pigment were optimized: The concentration of , NaNO2 content, ascorbic acid content, pH, temperature and the reaction time which are affecting the synthesis were studied through the single factor experiment. Based on the single factor experiment, the response surface analysis were used to optimize the various conditions of the main factors affecting absorption, the regression equation of the NaNO2 amount （x1）, ascorbic acid content （x2） and pH （x3） on absorbance （Y） can be gotten. The optimum combination of NaNO2 content, ascorbic acid content and pH is: 0.53 ml, 272.37mg, 4.51, its response to the corresponding value for absorbance 0.91.3.Under the 450-650 nm scan, the spectrum picture of pigment extracted by 80% aqueous acetone are the same as dinitrosyl ferrohemochrome （DNFH） and HbNO reported before, which indicated that the structure of them were similar.4. The experiment of pigment stability showed that: pigment was stable in 40min, and the high temperature over 85℃caused a lot of chromoproteins deposited after 40min which illuminated that a lot of chromoproteins were lost caused by this temperature and heating processing light was a certain impact on pigment stability, but far less than the light pigment of acetone extract of the impact. There was no effect on pigment under short time ultraviolet radiation.Cu2+ and Ag+ have a greater impact on pigment solution, when the two are put into soon there have joining muddy; Zn2+ and Fe3+ have little effect on the stability of solution. Ascorbic acid was relative to the stability of pigment, but the affection was not prominent. On the other side, saccharose and glycerin boost up the stability of pigment.5. The rheological properties of pigment were studied, The results showed as follows: when temperature is 25℃, 12% of the pigment solution is the fake plastic fluid of non-Newtonian fluids, non-Newtonian index is n=0.58, consistency coefficient is K=0.63; The sticky flow activation energy of 12% of the pigment solution is 28.38 kJ/mol; when temperature is 4°C, the apparent viscosity of pigment increase as the concentration of pigment solution increased, when the concentration is higher than 9%, the viscosity increase rapidly as concentration increased. At higher concentrations, the apparent viscosity of solution decrease as shear rate increased, and performs as fake plastic flow of non-Newtonian fluid, and while the concentration is <8%, the solution is Newton.fluid.
There are abundant proteins and amino acid in the porcine blood and its nutrient value is high. Haemoglobin is an important ingredient in the porcine blood,which is more than 75%of total protein in the porcine blood and more than 90%of total blood corpuscle protein.Iron deficient anemia is one of the most common anemias in the world,and is also an important global nutrition deficient disease.The polypeptide-iron is a novel bio-active iron with stimulativeless and high bioavailability,which can be absorbed directly by the intestinal cells.Therefore,is gotten from fresh porcine blood;then,based on the chelating response between molysite and ,polypeptide-iron can be processed,and its anti-anemia results were aslo studied in this paper.The results showed as follows:1.The fresh porcine blood is used as material in the research.In the preparation process of ,the conditions of the discolouration,desalination and ultrafiltration and its sensory evaluate were discussed.The results indicated that:(1)The optimum parameters of the discolouration process are activated carbon concentration 2.0%,pH 5.0,temperature 50℃and time 1.5h.(2)The best flow velocity of the desalination process is 2BV/h.(3)The optimum parameters of the ultrafiltration are the operation pressure 0.15Mpa and temperature 25℃.(4)The polypeptides are divided into four kinds of the molecular weight scopes by ultrafiltration.The molecular weight scopes are more than 10kDal,5-10kDal,1-5kDal and less than 1kDal,and the content is 4.38%,13.97%,74.76%and 6.89%respectively,the most of polypeptides is 1-5kDal.(5)The polypeptides are canary powder,slightly bitter and without blood odor.2.The synthesized conditions of haemoglobin polypeptide and ferrous chloride were studied, and the component of the product has also been discussed.The results indicated that:The best chelating process conditions is the ferrous chloride chosen for the iron source of chelation,pH 5.0, the ratio ofpolypeptide to ferric chloride 3:1 and 3.0%polypeptide concentration. is proved that the polypeptide-iron is a new product in the form of chelation and is different from the haemoglobin polypeptide and the ferrous chloride.3.By the means of low-iron diet and weekly tail vein bleeding,the iron deficiency anemia rat model was successful accomplished after four weeks.And is proved that the polypeptide-iron can improve the effect of the iron deficiency anemia in rats,and anti-anemia results are clearly better than the ferrous glucose acid and ferrous chloride.Therefore,The polypeptide-iron can be used as an efficacious iron preparations for improving the iron deficiency nutrition anemia.
This paper focused on extracting molasses and producing fuel ethanol by utilization of citrus processing-residues. This study involved in extraction of citrus molasses, analysis of molasses composition,, optimization of fermentation conditions, distillation of condensed fermented mash and preparation of dehydrated alcohol in order to exploring feasibility of industrialized fuel alcohol manufacture..The citrus wastes were mixed fully with 0.3% quicklime （weight bass）, recation completely by standing for 20 minutes, the mixture was pressing by presser and filtered by finisher to obtain filtrate. Standing was performed for 12 hours and the oils over filtrate were removed by siphonic process. The filtrate was concentrated into 40°Brix molasses by vacuum rotary evaporation.The citrus pulps excreted from finisher were washed for 5 times to recover all sugar. The pulp wash could either be fermented directly or diluted with citrus molasses before fermentation. could also be concentrated and mixed with citrus molasses for fermentation and alcohol productionThe results of composition analysis of citrus molasses and pulp wash were given as follow that the soluble solids content of the citrus press juice was 11.8°Brix, reducing sugar 5.57g/100ml, total sugar 9.28g/100ml, oils 0.756%（by weight）.While molasses was 40°Brix, the reducing sugar 15g/100ml, total sugar 34g/100ml and oils 0.05%（by weight）.The contents of pectin in pulp wash and molasses were 0.474% and 0.653% respectively.There was not significant influence on growth of Saccharomyces cerevisiae if content of the oils in dilution solution of molasses was lower than 0.03%.However, when the content exceeds 0.04%, the growth of Saccharomyces cerevisiae was significantly affected by the oils and the lag phase was extended. In our study, the content of the oils in dilution solution of molasses was lower than 0.04% and fermentation was not influenced obviously.Through comparative assay about 6 strains of X1, X2, X3, X4, X5 and X6, indicated that X4 was the optimal strain for fermentation resulting either the alcohol yield or the suitability in citrus molasses culture medium. The yields of ethanol from directly waste sugar solution and citrus molasses fermented by X4 were 20g/L and 72g/L respectively.In single factor experiment, the superior conditions could be 25°Brix medium of molasses, 1.8 g/L, （NH4）2SO4 , 0.6g/L KH2PO4 and 0.6g/L MgSO4,pH 5.0 and inoculums size was 3×107individual/ml, and ethanol yield was 82.4 g/L.The optimal technological conditions determined by orthogonal experiment were initial pH 5.0, inoculums size 3×107individual/ml under 30℃. The maximum alcohol yield was got.Experiments In 15L fermentor based on single factor and an orthogonal experiment was carried out fermentation curves were similar with those from shake flasks except a shorter lag phase. could be confiremed that fermentation ability of this strain both in fermentor and shake flasks were no difference. It also manifested the stabilized fermented ability of this strain proved by amplified experiment after shake flasks.At last, 95% alcohol was obtained after atmospheric distillation 3 times and vacuum distillation once.The citrus molasses were made from s which was no cost. Through economical analysis, citrus molasses alcohol has competitive advantage comparing with corn alcohol and sweet sorghum stem alcohol. Industrial manufacture would be feasible if there were sufficient s and thus citrus molasses would be a kind of potentially biological energy sources.In a word, it was concluded that after proper processing, citrus molasses could be obtained from the citrus residues and then fermented into alcohol. It was also valuable to make comprehansive utilization of the citrus residues with a strong competitive strength to produce fuel ethanol.
S-adenosyl-L-methionine（SAM）is an important metabolic intermediate in organism which is involved in many biochemical reaction.There are vast market for SAM as nutrient and drug.Our main task is carries on screening to yeast,and itsconditions to do research.The separation and purification of them were preliminary studied.SAM can be obtained by three ways:chemosynthesis,enzymatic conversion technique,as well as microbial ,of which is the primary way of industrial production.In our experiment one was choosen from four strains to produce SAM high saccharomycetes Sake,its output is the 1.71g/L.By the space-mutation Yeast Sake,was picked out 500 yeasts,then through refilter we obtained one to produce the SAM high strain,No.552 of the yeast than the originally and its production output increase 11.16%.By the fermentation,fermentation conditions Sake552 strain of did conduct a preliminary exploration. were studied and identified the best initial pH is 5.0,while SAM accumulation phase is 6.0 in shake flask;best fermentation temperature is 28℃;Best medium are 20%distilled potatoes, glucose 7%,yeast extract 1%,Urea 1.4%,L-Met 1%,KH2PO4 0.4%,K2HPO40.2%,MgSO4·7H2O 0.5%, CaCl2·2H2O 0.2%.The culture conditions of the Yeast Sake 552 in fermentor 5L were optimized, including the prescription of cultural medium,pH,dissolved oxygen,agitation speed,aeration,feeding strategy of complementarity-cultural medium in different stages.The SAM content of the Yeast Sake 552 reached 3g/L after fermentation for 4 days under the optimized conditions.We also has researched the separation and purification process of SAM and has established a preliminary technics.The procedure followed with that the cell suspension of pH2 to be frozen for 24h then to disrupt and then purify with weak acid cation exchange resin,to crystal and deposit with methanol,to centrifugal deposition to freeze-dry it finally we got the crude SAM.