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The use of antibacterial packaging materials is an effective way to delay fruit rotting and spoilage, thereby minimizing economic losses and health hazards. Natural antibacterial agents, especially essential oils, are often selected as antibacterial components in antibacterial packaging materials, due to their excellent antibacterial properties. However, their low water solubility, poor stability, and easy volatility result in materials containing them having poor mechanical properties and short antibacterial efficacy time. Therefore, in this work, the citral loaded Pickering emulsion was prepared using chitosan and self-made carboxymethyl glucan self-assembled nanoparticles as emulsifier. Then, composite films with good transparency, excellent mechanical properties and long-term antibacterial properties for fruits packaging were prepared from chitosan (CS), carboxymethyl-glucan(CMG), poly(vinyl alcohol)(PVA), and Pickering emulsion(PE)by solvent casting strategy. Pickering emulsion has a protective effect on citral, which not only improves the compatibility of citral in composite film substrate, but also extends the antibacterial time of packaging materials. In this experiment, the transparency of the antibacterial composite film containing Pickering emulsion(CS-CMG-PVA-PE1)was 84%, the tensile strength was 32 MPa, and the elongation at break was 130%. More importantly, the composite polymer solution can be dipped directly on fruits as a coating for food storage to improve food shelf life, substantially expanding its ease of use and scope of use. [ABSTRACT FROM AUTHOR]

Due to the poor salt resistance of polyaerylamide polymers, the technology of polymer flooding for enhanced oil recovery in high calcium and magnesium reservoirs is limited. By introducing the suspended microcrystalline polymer system, it becomes beneficial for the injection of water containing the high- concentration calcium and magnesium ions. The self-developed tackifier turns the calcium and magnesium ions into microcrystals, and associates the microcrystals with polymer molecules to form a local network. The structure of the three-dimensional macromolecules has the properties of anti-calcium and magnesium, thickening, and the increased viscosity of the polymer solution. The optimum concentration of dispersant and crystallization agent in suspended microcrystalline polymer system is 0.2% and 0.3%, respectively. The polymer is preferably hydrophobic associative polyaerylamide polymer. [ABSTRACT FROM AUTHOR]

Linear polyacrylamide (LPA) was synthesized through an oxidation-reduction initiator system in aqueous solution. Linear polyacrylamide/poly(N, N-dimethylacrylamide) (LPA/PDMA) and linear polyacrylamide/poly(N-hydroxyethyl acrylamide) (LPA/PHEA) quasi-interpenetrating polymer networks were synthesized by polymerizing N, N-dimethylacrylamide (DMA) and N-hydroxyethyl acrylamide (HEA) in LPA aqueous solution, respectively. Characterization techniques, including ¹H-Nuclear Magnetic Resonance Spectra (¹H-NMR), Fourier Transform Infrared Spectrometer (FT-IR), and Differential Scanning Calorimetry (DSC), were employed to analyze the structures. The intrinsic viscosity of LPA, LPA/PDMA and LPA/PHEA were determined using a Ubbelohde viscometer, and the viscosity average molecular weight (Mη) was calculated based on the intrinsic viscosity. The rheological properties of the above quasi-interpenetrating polymer networks were systematically investigated, focusing on the effects of LPA intrinsic viscosity molecular weight, shear rate, temperature, and other factors. When the mass concentration of polymer(ρ) is less than the critical entanglement concentration(ρ*), the specific viscosity(ηsp) of LPA solution increases slowly with ρ. When ρ is more than ρ*, ηsp increases rapidly with ρ. And ρ* of LPA solution decreases as molecular weight increases. LPA, LPA/PHEA, and LPA/PDMA solutions exhibit significant shear-thinning behavior, and the apparent viscosity(η) of LPA/PHEA and LPA/PDMA solutions is significantly lower than that of the corresponding LPA solution. The η of polymer solutions decreases with increasing temperature, and LPA/PHEA and LPA/PDMA are more temperature-sensitive. The viscoelastic results show that in the linear viscoelastic region, at a mass concentration of 0.025 g/mL, polymer solutions based on medium and high molecular weight LPA are predominantly elastic, indicating a relatively stable polymer network structure, while those based on low molecular weight LPA are predominantly viscous, indicating that the polymer network structure is unstable and easily disrupted by external forces. [ABSTRACT FROM AUTHOR]

The apparent viscosity, rheology, resistance and residual resistance coefficients, microstructure and hydrodynamic radius of polymer solution after shearing by well transition zone shear simulation experiment device were investigated with hydrophobic polymer AP-P4 under different water absorption strength conditions. The results showed that the polymer AP-P4 solution lost up to 61.4% of viscosity and reduced more than 40.0% of its ability to build up the drag and residual drag coefficients with the increase of water absorption strength after shearing by the well ground transition zone, but the reduction of its ability to build up the residual drag coefficient was smaller than the reduction of its ability to build up the drag coefficient. The lower the energy storage modulus and loss modulus of the polymer solution, the more severely the microstructure is disrupted, and the smaller the hydrodynamic radius. [ABSTRACT FROM AUTHOR]

Synergistic therapeutic effect through the intracellular co-delivery of chemotherapy and biomacromolecule drugs is a novel strategy for improving tumor treatment effectiveness. A triblock copolymer, poly(acrylic acid)-poly(N, Ndiisopropylaminoethyl methacrylate)-poly(N-vinylcaprolactam) (PAA-PDPA-PNVCL), was designed and synthesized for the construction of smart responsive drug carriers. The structure of the polymers was verified by nuclear magnetic resonance spectroscopy (¹H-NMR) and fluorescence spectrophotometer (FL). The transmittances of the polymer solutions under different pH values or temperatures were measured by ultraviolet-visible spectroscopy (UV-Vis). Results showed that the polymer had excellent pH responsiveness and a low critical solution temperature (LCST), which could self-assemble into vesicles with PAA as hydrophilic shell, PDPA as hydrophobic intermediate layer and PNVCL as hydrophilic cavity. Then, the PAA shell layer was crosslinked with disulfide bonds through amide reaction, to improve the structural stability of vesicles and meanwhile introduce the reduction sensitivity. The changes of the particle size, Zeta potential, and morphology of the vesicle under different conditions were studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Results showed that the shell-crosslinked vesicles were uniformly sized spherical structure with good pH value and reduction responsiveness. Their drug encapsulation effect and in-vitro release behavior under different pH values and glutathione (GSH) concentrations were studied by UV-Vis and FT-IR. Results showed that the carriers could achieve zoned and co-loading of hydrophobic small molecule drug (doxorubicin (DOX)) and hydrophilic macromolecular protein drug model (bovine serum protein (BSA)). The hydrophobic layer of PDPA and the crosslinked layer of PAA provided dualblockade for drug leakage. The leakage of drugs under normal physiological conditions was low, and the release of DOX and BSA could only be triggered under simulated tumor microenvironment, that is, weak acid and high concentration of GSH conditions. The smart responsive drug carriers constructed in this paper are expected to achieve co-delivery of chemotherapy and biomacromolecule drugs, which have potential application value to the clinical treatment of tumors. [ABSTRACT FROM AUTHOR]

Copyright of Oilfield Chemistry is the property of Sichuan University, Oilfield Chemistry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The characteristics of polymer materials, the advantages of using polymer materials in industrial design and the common polymer materials in industrial design are introduced. Based on the perspective of technical aesthetics, the application technology of polymer materials in industrial design is classified and discussed from the aspects of injection molding technology, thermoforming technology, extrusion molding technology and 3D printing technology, and the innovative application cases of polymer materials in industrial design technical aesthetics are summarized. The challenges and solutions of using polymer materials in industrial design are proposed. In the future, it is necessary to further explore the aesthetic rules in the field of industrial design, and enrich the application scope of industrial design of polymer materials under the guidance of technical aesthetics. [ABSTRACT FROM AUTHOR]

Poly(ethylene glycol) monomethyl ether-poly(2-diisopropylaminoethyl methacry-late)-poly(acrylamide-coacrylonitrile) (mPEG-PDPA-P(AAm-co-AN)), a novel amphiphilic triblock ABC polymer, was designed and synthesized. This polymer was prepared by atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer polymerization (RAFT). When pH changes, PDPA undergoes a hydrophilic-hydrophobic transition. Therefore, the polymer has pH-responsivity with a pH-sensitive point at pH 6.53. The P(AAm-co-AN) fragment forms hydrogen bonds at low temperature. At high temperature, hydrogen bonds are formed between the polymer chains and water molecules so that the polymer mPEG-PDPA-P(AAm-co-AN) has a high critical solution temperature (UCST). By varying the monomer ratios of acrylamide (AAm) to acrylonitrile (AN) and the concentration of the solution, polymers with different UCSTs can be obtained. In a neutral environment at room temperature, the polymer solution forms micelles by self-assembly with mPEG as the shell and PDPA and P(AAm-co-AN) as the core. The particle size, potential and morphology of the micelles in various external environments were studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM). An increase in temperature induces a transition from micelles to asymmetric vesicles. The lower pH encourages the polymer to form looser micelles. Simultaneously changing the pH and temperature, the hydrophilicity of each block of the polymer increases, the micelles dissolve sufficiently, and the particle size increases. In an in vitro drug release investigation, polymeric micelles show good drug delivery for both the hydrophilic drug doxorubicin (DOX) and the hydrophobic drug quercetin. The micelles show low leakage at 37 ℃ and pH 7.4. The release rate of drug from the micelles increases significantly with the increasing of temperature and the decreasing of pH. It is demonstrated that the polymeric micelles have good environmental stimulus sensing ability and controlled drug release. [ABSTRACT FROM AUTHOR]

Auramine O may be illegally used as a food colorant because of its cheapness and easy to enhance color, causing great harm to human health. Therefore, it is of great significance to establish a sensitive and rapid method for the determination of auramine O in food. In the experiment, reduced graphene oxide and gold nanoparticles sol are used to modify working electrodes, a polymer film is formed by cyclic voltammetry on the surface of the modified electrode with auramine O as template molecule, o-aminophenol and o-phenylenediamine as composite functional monomers. The template molecules are eluted using constant potential of −0. 1 V in methanol-0. 5 mol/L NaOH aqueous solution (1∶1, V/V), the molecularly imprinted electrochemical sensor (MIECS) is prepared successfully for detection of auramine O. Electrochemical analysis method is used to optimize the ratio of template molecules to composite functional monomers. The polymer solution pH and cylinder number, the morphology and chemical structure of the membrane are characterized by scanning electron microscope and infrared spectrometer. The imprinting effect and analysis performance of the sensor are investigated. The results show that the sensor has specific adsorption to auramine O. Under the optimal conditions, the auramine O has a good linear relationship in the concentration range of 1. 0×10−9~3. 0×10−5 mol/L, the detection limit is 3. 3×10−10 mol/L, and the average recoveries are between 91. 16% and 101. 61% with the relative standard deviations（RSDs）of 2. 79%. The sensor has good stability and reproducibility, and is suitable for sensitive and rapid detection of auramine O in food samples. [ABSTRACT FROM AUTHOR]

Improving the foam stability in the presence of crude oil seriously affects the performance of foam enhanced oil recovery （EOR). The stability of SDBS/nano-SiO2/thixotropic polymer （WTP） foam in the presence of crude oil were studied by a series of laboratory experiments, such as static evaluation, microscopic visualization and morphology characterization. The results show that SDBS/nano-SiO2/WTP foam system has a good foam-stabilizing performance in the presence of light crude oil. When crude oil flows to the liquid film between bubbles, the high viscosity generated by the spatial network formed by thixotropic polymers in the liquid film will greatly increase the flow resistance of the oil phase. The “solid shell” formed by the adsorption of nano-SiO2 particles on the surface of the liquid film can prevent the invasion of crude oil into the liquid film and reduce the bubble coalescence rate of the film after drainage. The enhancement of foam stability in the presence of oil can improve the conformance control performance in fractured low-permeability reservoirs. [ABSTRACT FROM AUTHOR]

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Liquid Crystal & Displays is the property of Chinese Journal of Liquid Crystal & Displays and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Advances in New & Renewable Energy is the property of Editorial Office of Advances in New & Renewable Energy and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A porous polymer membrane was formed by immersion precipitation in a solution using the copolymer of vinylidene fluoride and hexafluoropropylene (PVDF--HFP) as film-forming material and acetone as solvent. A porous polymer electrolyte membrane (PPEM) was then prepared by immersing the said membrane into a 1 mol/L LiPF6-containing ionic electrolyte composed of ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC). The effects of the mass fraction of PVDF--HFP and the temperature of coagulation bath on the electrolyte uptake, ionic conductivity, and electrochemical stability window of PPEM were studied. The results showed that the PPEM obtained with 20% of PVDF--HFP in polymer solution and at a coagulation bath temperature of 25 °C featured an electrochemical stability window of 5 V and an electrolyte uptake of 40.2%. However, its ionic conductivity was only 1.52 x 10-4 S/cm and needed to be improved. [ABSTRACT FROM AUTHOR]

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Surfactants can change the performance of acid self-thickening polymer solution and improve the thickening ability of acid solution. An acidified self-thickening agent(ADD) was synthesized from acrylamide(AM), N-(3-dimethylaminopropyl) methylacrylamide (DMAPMA) and octadecyl dimethyl allyl ammonium chloride(DMAAC-18), the effects of surfactant on the thickening properties of self-thickening polymer and the rheological properties of spent acid were studied. The results showed that the peak viscosity of self-thickening acid solution could be increased from 429 mPa·s to 513 mPa·s, when the dosage of sodium dodecyl sulfate (SDS) was 32. 85 g at 30 ℃ and 5%(based on the mass of self-thickening polymer). At the shear rate of 600 s-1, the viscosity of ADD-SDS spent acid increases from 99 mPa·s to 182 mPa·s, and has greater kinetic modulus. After adding 2. 94 times water, the viscosity of ADD-SDS spent acid solution is reduced to less than 10 mPa·s, which has better flowback ability. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Oil Drilling & Production Technology / Shiyou Zuancai Gongyi is the property of Shiyou Zuancai Gongyi Bianjibu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Liquid Crystal & Displays is the property of Chinese Journal of Liquid Crystal & Displays and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Oil Drilling & Production Technology / Shiyou Zuancai Gongyi is the property of Shiyou Zuancai Gongyi Bianjibu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Oil Drilling & Production Technology / Shiyou Zuancai Gongyi is the property of Shiyou Zuancai Gongyi Bianjibu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The numerical analysis of flow-induced structures of complex fluids is one of effective approaches for elucidating the mechanism of their complicated flow behavior. In this article, three examples of the numerical simulation of the flow-induced structure using the Brownian dynamics (BD) method and the multi-particle collision dynamics (MPCD) method are presented: (a) BD simulation of shear flows of polymer/clay suspensions, (b) MPCD simulation of shear flows of linear polymer solutions, and (c) MPCD simulation of bio-convection of phototactic microalgae in water. In these simulations, complex fluids are modeled by dispersion systems of basic elements of the fluid inner structure such as particles and model polymers, and their behavior is analyzed for the investigation of the flow-induced structure. [ABSTRACT FROM AUTHOR]

As the development of polymer flooding, polymer contained blockage was appeared and the oil well production was decreased in SZ36-1 oilfield. In this paper, the components of blockage in polymer flooding injection well (PFIW) and response well (PFRW) were compared by several characterization methods firstly. The inorganic scale was the main substance in collected samples, the mass ratio of inorganic scale and organic scale in PFRW blockage was 4.0-5.5, which was much larger than that of PFIW (0.25-0.75). The inorganic scale mainly was Fe2O3 in PFIW and and CaCO3 in PFIW, and the organic scale was partially hydrolyzed polyacrylamide. Then, the formation mechanisms of inorganic scale and organic scale in PFRW and PRIW were investigated, especially the formation mechanism of blockage in PFRW was studied. In the area which was close to the response oil well, there was a lot of Fe3+ in residual acid solution after the acidification operation, and when it was mixed with polymer flooding solution, Fe(OH)3 was formed as the pH increased and Fe2O3 blockage was formed after the oxidation. In addition, the cross-linked polymer blockage which was organic scale, was formed by the selective coordination between polymer and Fe3+ when the degraded polymer was mixed with Fe3+ solution in acid condition. The results in this paper are helpful for the targeted removal of plugging in PFRW or PRIW and preventive blockage in PRIW. [ABSTRACT FROM AUTHOR]

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The influences of Fe2+ on the apparent viscosity of polymer solution have been studied in this paper, and the results showed that a small amount of Fe2+ would make the polymer degraded severely. HPAM polymer molecular weight and viscosity declined dramatically with the increasing of CFe2+ among the 0~0.5 mg/L, and declined slowly when the CFe2+ above a concentration of 0.5mg/L. The AFM photos also showed that polymer network structure was destroyed largely. In order to ensure the polymer viscosity, the contents of Fe2+ in preparation water should not exceed to the concentration of 0.5 mg/L. There are several controlling measures used to remove Fe2+ in preparation water, such as oxygen exposure, chemical complex method and manganese sand filtration. Chemical complex method is the most simple and effective one among them. The high effective iron removal reagent BHCT-1 with a concentration of 300 mg/L showed a good effect to remove Fe2+. For example, it was applied in offshore polymer flooding oilfield, and the viscosity of polymer solution would be increased by more than 20%. [ABSTRACT FROM AUTHOR]

To keep the thermal stability of polymer-surfactant dual-compound systems for a longer period. Some type of nonionic surfactant (0.10~0.20 wt%) is added to the polymer solution (2000 mg/L) diluted by produced water, and then, the system was aged for 60 days at 53 °C under the oxygen-deprived conditions. Following that, the thermal stability and the extent of reducing water-oil interface tension of the system were evaluated. The results showed that, after adding the surfactant and aging for 60 days, viscosity retention rate is improved from 22.3% up to 71.4%, and the water-oil interface tension is still within the order of 10-3 mN/m. The tentative practice which adopts this system to tentatively inject the solution combine polymer and surfactant into the reservior suggests that it reduce the water-oil interface tension down to the grade of 2.59×10-3; the viscosity of the solution remains the rate of 72%, even if the solution is kept in the same 53 °C for about 60 days; and the injection pressure enhances 1 MPa compared with the former conditions. [ABSTRACT FROM AUTHOR]

A certain concentration of polymer is contained in the treated sewage of polymer flooding produced liquid. The treatment of polymer-containing sewage is a problem in field. Preparing the polymer solution using sewage instead of fresh water can solve this problem very well. By this way, it has a certain effect to polymer viscosity. Can the polymer solution be affected by the polymer retained in the waste water? The factors affecting polymer viscosity were found out through the determination of hydrolysis degree, relative molecular mass, form in water, sewage viscosity of polymer flooding produced liquid and the analysis of sewage water quality. Meanwhile, factor analysis of hydrolysis degree increasing and relative molecular mass decreasing of polymer was carried out. Comparing with fresh water, Mg2+, Na+ , Ca2+ content is higher in the waste water, and it is the most significant for bacterial content to exceed standard, which should be the main reason for the loss of polymer viscosity. [ABSTRACT FROM AUTHOR]