Construction of coal pitch-based HA-K grafted poly condensates and their excellent anti-temperature and viscosity-reducing properties

Humic acids(HAs)are widely used as filtrate and viscosity reducers in drilling fluids.However,their practical utility is limited due to poor stability in salt resistance and high-temperature resistance.Hightemperature coal pitch(CP)is a by-product from coal pyrolysis above 650℃.The substance's molecular structure is characterized by a dense arrangement of aromatic hydrocarbon and alkyl substituents.This unique structure gives it unique chemical properties and excellent drilling performance,surpassing traditional humic acids in drilling operations.Potassium humate is prepared from CP(CP-HA-K)by thermal catalysis.A new type of high-quality humic acid temperature-resistant viscosity-reducer(Graft CP-HA-K polymer)is synthesized with CP-HA-K,hydrolyzed polyacrylonitrile sodium salt(Na-HPAN),urea,formaldehyde,phenol and acrylamide(AAM)as raw materials.The experimental results demonstrate that the most favorable conditions for the catalytic preparation of CP-HA-K are 1 wt%catalyst dosage,30 wt%KOH dosage,a reaction temperature of 250℃,and a reaction time of 2 h,resulting in a maximum yield of CP-HA-K of 39.58%.The temperature resistance of the Graft CP-HA-K polymer is measured to be 177.39℃,which is 55.39℃ higher than that of commercial HA-K.This is due to the abundant presence of amide,hydroxyl,and amine functional groups in the Graft CP-HA-K polymer,which increase the length of the carbon chains,enhance the electrostatic repulsion on the surface of solid particles.After being aged to 120℃ for a specified duration,the Graft CP-HA-K polymer demonstrates significantly higher viscosity reduction(42.12%)compared to commercial HA-K(C-HA-K).Furthermore,the Graft CP-HA-K polymer can tolerate a high salt concentration of 8000 mg.L-1,measured after the addition of optimum amount of 3 wt%Graft CP-HA-K polymer.The action mechanism of Graft CP-HA-K polymer on high-temperature drilling fluid is that the Graft CP-HA-K polymer can increase the repulsive force between solid particles and disrupt bentonite's reticulation structure.Overall,this research provides novelty insights into the synthesis of artificial humic acid materials and the development of temperature-resistant viscosity reducers,offering a new avenue for the utilization of CP resources.

Synthesis,characterization and evaluation of polyacrylamide graft starch/clay nanocomposite hydrogel system for enhanced oil recovery

In this paper the suitability of a graft polymer nanocomposite hydrogel system for enhanced oil recovery was examined using polyacrylamide graft starch/clay nanocomposite(a laboratory synthesized product) and chromium(III) acetate(crosslinker). X-ray diffraction analysis,Fourier transform infrared spectrometry analysis, field-emission scanning electron microscopy and transmission electron microscopy were carried out to reveal the laboratory synthesized product as a nanocomposite. The effects of various parameters like salt concentration, p H, temperature, polymer concentration and crosslinker concentration on the properties of the developed gel system were systematically evaluated.The thermal stability of the nanocomposite gel and the conventional gel system were also determined by thermogravimetric analysis. The graft polymer nanocomposite gel system exhibited acceptable gel strength, gelation time and gel stability compared with the conventional gel system. The nanocomposite gels prepared using a low crosslinker concentration showed higher gel strength and required longer gelation time than the conventional gel which is more desirable properties for the effective placement of gel during enhanced oil recovery operations. In addition, sand pack flooding experiments show that the graft polymer nanocomposite gels had better plugging capacity than the conventional gel systems under reservoir conditions. Hence, this gel system may be suitable in the water shutoff treatments required for enhanced oil recovery from oilfields.

Plasma Induced Grafting of PMMA onto Titanium Dioxide Powder

Grafting of polymer of methyl methacrylate （PMMA） onto titanium dioxide powder is investigated in this paper. The graft polymerization reaction is induced by dielectric-barrier- discharge produced N2 plasma treatment of titanium dioxide surfaces. IR, XPS and TGA results show that PMMA is grafted onto the surfaces of titanium dioxide powder. And crystal structure of the titanium dioxide powder observed with XRD spectra is unchanged after plasma graft polymerization.

Synthesis of PGMA Microspheres with Amino Groups for High-capacity Adsorption of Cr(VI) by Cerium Initiated Graft Polymerization

Abstract A novel polyglycidylmethacrylate （PGMA） microspheres with high adsorption capacity of Cr（VI） was prepared by cerium（IV） initiated graft polymerization of tentacle-type polymer chains with amino group on polymer microspheres with hydroxyl groups. The micron-sized PGMA microspheres were prepared by a dispersion polym erization method and subsequently modified by ring-opening reaction to introduce functional hydroxyl groups. The polymer microspheres were characterized by scanning electron microscopy （SEM） and Fourier transform infrared spectroscopy （FTIR）. The results indicated that the polymer microspheres had an average diameter of 5 m with uniform size distribution. The free amino group content was determined to be 5.13 mmol·g^-1 for g;PGMA-NH2 microspheres by potentiometric and conductometric titration methods. The Cr（VI） adsorption results indicated that the graft polymerization of tentacle-type polymer chains on the polymer microspheres could produce adsorbents with high adsorption capacity （500 mg-g-l）. The polymer microspheres with grafted tentacle polymer chains have potenial application in large-scale removal of Cr（VI） in aqueous solution.

Preparation of Chelating Polymer Grafted Magnetic Adsorbent and Its Application for Removal of Pb(Ⅱ) Ions

A novel magnetic chelating adsorbent （CPMS） with iminodiacetate functionality was prepared by polymerization of glycidyl methacrylate-iminodiacetic acid （GMA-IDA） monomer with N, N-methylenebisacrylamide as crosslinker in the presence of monodisperse magnetic silica microspheres （MS）. CPMS was characterized by IR, SEM, VSM and TGA. The experimental results revealed that MS was embedded in the gel polymer, but the morphology of CPMS was irregular. The saturation magnetization for CPMS was found to be 28.4 emu/g, and the percentage of GMA-IDA polymer grafted on MS was about 46.5%. CPMS were shown to be efficient for the removal of Pb（II） ions at pH 3.0 - 6.0, and the adsorption data obeyed the Langmuir equation with a maximum adsorption capacity of 54.4 mg？g？1 at pH 5.0. Moreover, the adsorption rate of CPMS was fast and it took about 5 minutes to achieve adsorption equilibrium in aqueous solution of lower lead ions concentration.

Preparation of Cationic Chitosan-Polyacrylamide Flocculant and Its Properties in Wastewater Treatment

Chitosan derived from crab shells, was used to prepare the graft polymer in aqueous solution with acrylamide （AM） and methacrylatoethyl trimethyl ammonium chloride （DMC） as raw materials and ceric ammonium nitrate （CAN） as initiator. The flocculation ability of the resulting polymer （PCAD） was studied in waste water treatment experiments. Its properties were determined on the basis of the transmittance of waste water after flocculation. The effects of ehitosan and DMC content on PCAD＇s flocculation ability were studied. Floeculation experiments were also undertaken under various pH conditions. According to the experimental data, the flocculation ability could be improved when chitosan content decreased in the raw material, but the monomer conversion would decrease obviously. When the ehitosan＇s content was more than 65%, AM and DMC groups were less on each chitosan molecule. So PCAD＇s flocculation ability was poor. Similarly, high content of DMC would result in low monomer conversion and high flocculation ability. PCAD molecules with more DMC group had more positive charges. It was favorable to flocculation. However, monomer conversion would decrease with the increase of DMC content. The suitable conditions were that chitosan and DMC contents were 65% and 15-20%, respectively. The experiment data showed that PCAD had good flocculation ability under weak acidic condition. Its ability would be weakened by strong acidic or alkaline condition. The flocculation efficiency was the best at pH of 5.5 when PCAD＇s dosage was 8mg-Lk Compared with cationic polymer （the copolymer of AM and DMC, PAD）, PCAD showed better flocculation ability under acid and neutral conditions, but worse ability under alkaline condition.

Amphiphilic Polyphosphazene with Poly(ethylene oxide) Side Chains Prepared through the Decker-Forster Reaction

Poly （4- methylphenoxyphosphnzene ） -graft-poly （ ethylene oxide ） （ PPZ-g- PEO ）, a novel amphiphilie grafting polymer was prepared via the Decker-Forster reaction. It is found that the graft efficiency increased with extension of reaction time. Low molecular weight of poly （ ethylene oxide ） favored the grafting reaction. The grafted polymer has two different glass transition temperatures（ Tg） with those of pure poly（ 4-methyl- phenoxy-phopsphazene ） and PEO. The emulsifying ability of grafted polymer was studied with benzene-water mixtare. The emulsifying volumes increased with the decreasing of PEO＇ s molecular weight. The contact angle of film forming from grafted polymer decreased after introduction of PEO grafting chain.

Applications of DOSY NMR in the Chemical IndustryApplications of DOSY NMR in the Chemical Industry

DOSY(diffusion ordered spectroscopy)NMR is a technique that separates NMR signals of different species according to their diffusion coefficients.It is a powerful technique to provide solid characterization evidence for various applications in the chemical industry.Encapsulation and functional polymer grafting are two important capabilities in the chemical industry for new product development with challenging characterization requirements.Model systems of encapsulation and grafted polymer were studied and the characterization methods were set up by DOSY NMR.

Continuous Synthesis of Main-Chain-type Fluorinated Graft Copolymers via Successive Flow START Polymerization and Cu(0)-Mediated RDRP

Fluorinated polymers are receiving more and more attention worldwide due to their unique chemical properties,and modified fluorinated polymers with different topologies are persued for enriching and enhancing their performance in a variety of application fields.In this work,main-chain-type semifluorinated graft copolymers are produced steadily in continuous tube reactors via photocontrolled step transferaddition and radical-termination(START)polymerization and Cu(0)-mediated reversible deactivation radical polymerization(Cu(0)-RDRP)at room temperature for the first time.Specifically,semifluorinated alternating copolymer(AB)n B is prepared by START polymerization of 1,6-diiodoperfluorohexane(A)and 1,7-octadiene(B)in the first quartz pipeline under irradiation with purple LED light at 20℃.The(AB)nB with periodic C―I bonds is then flowed into the second copper pipeline directly and acts as the macroinitiators for Cu(0)-RDRP of methyl acrylate(MA)to obtain corresponding graft copolymer(AB)n B-g-PMA.This work provides a new strategy for continuous synthesis of fluorinated graft copolymer materials.

Effect of Preparation Process of Functional Polymer Active Materials on Properties of Gadolinium Ion Selective Electrode

Recently we have studied the rare earth ion-selective electrodes with active materials of the func-tional polymers and found that the process chosen for the functional polymers had an effect on the propertiesof gadolinium ion selective electrode besides the effects of their structures.1.Effect of preparation process of the grafted polymers on the properties ofgadolinium ion selective electrodesThe electrode membranes which consist of functional polymers as active materials were prepared by re-action of gadolinium chloride with the radiation grafted clmer of acrlic acid and polystyrene of which

Tunable wavelength filters using polymer long-period waveguide gratings based on metal-cladding directly defined technique

In this work, long-period waveguide grating-based tunable wavelength filters using organic–inorganic grafting poly（methyl methacrylate）（PMMA） materials are designed and fabricated by metal-cladding directly defined technique.The thermal stabilities and optical properties of the organic–inorganic grafting PMMA core materials are analyzed. Structures and performance parameters of the waveguide gratings and self-electrode heaters are designed and simulated. The contrast of the filter is about 15 d B and the resonant wavelength can be tuned by different electric powers applied to the metal-cladding self-electrode heaters. The temperature sensitivity is 3.5 nm/℃ and the switching time is about 1 ms. The technique is very suitable for realizing the optoelectronic integrated wavelength-division-multiplexing systems.

Dielectric phenomena and electrical energy storage of poly(vinylidene fluoride) based high-k polymers

Polymeric dielectrics have wide range of applications in the field of electrical energy storage because of their light weight and easy processing. However, the state-of-the-art polymer dielectrics, such as biaxially orientated polypropylene, could not meet the demand of minimization of electronic devices because of its low energy density. Recently, poly（vinylidene fluoride） （PVDF） based ferroelectric polymers have attracted considerable interests for energy storage applications because of their high permittivity and high breakdown strength. Unfortunately, the high dielectric loss and/or high remnant polarization of PVDF-based polymers seriously limits their practical applications for electrical energy storage. Since the discovery of relaxor ferroelectric behavior was firstly reported in irradiated poly（vinylidene fluoride- trifluoroethylene） （P（VDF-TrFE）） copolyrner, many strategies have been developed to enhanced the electrical energy storage capability, including copolymerization, grafting, blending and fabricating of multilayer How these methods affect the polymorphs, crystallinity, crystal size of PVDF-based polymers and the connection between these microstructures and their corresponding energy storage properties are discussed in detail.

Polymers with complicated architectures constructed from the versatile, functional monomer 1-ethoxyethyl glycidyl ether

Because glycidyl(Gly) contains an epoxy and an active hydroxyl group, the Gly unit is difficult to introduce into certain polymeric chains in a controlled manner and usually yields hyperbranched polyglycidyl. Alternatively, the monomer 1-ethoxyethyl glycidyl ether(EEGE), derived from Gly and ethyl vinyl ether, has shown potential for application in polymer chemistry, and homopolymerization of this monomer directly produces linear poly(1-ethoxyethyl glycidyl ether) and further yields linear polyglycidyl. In this review, the initiation system of the EEGE monomer is first discussed in terms of chain transfer to monomers in ring-opening polymerization of epoxides with substituent groups. Then, random copolymerization of EEGE with other epoxides is considered. In addition, because the EEGE units on polymers can be transferred to Gly units and further used to construct copolymers with complicated architectures, the applications of EEGE monomers to block, graft, and hyperbranched copolymers are reviewed. Finally, the synthesis of main chain and terminal functional polyethers by transforming the hydroxyl groups at the polymer end or on the main chain into certain functional groups are also discussed. Chemistry based on EEGE has been proved to be an efficient, versatile route to constructing copolymers containing Gly units and ultimately yielding the target properties and applications.

Effect of GMA Polymer Compatibilizers on Highly Filled Composites of Low Density Polyethylene/Magnesium Hydroxide

Functional polymers such as polyethylene grafted glycidyl methacrylate （PE-g-GMA） and ethylene-methyl acrylate-glycidyl methacrylate terpolymer （E/MA/GMA） were used as compatibilizers in the preparation of highly filled composites of polyethylene/magnesium hydroxide（PE/MH）. Comparative studies were performed on the effect of magnesium hydroxide and stearic acid on the interface within polymer and magnesium hydroxide composites. The effect of polymeric compatibilizers on the properties of the composites was studied using tensile and impact tests, torque rheological analysis, differential scanning calorimetry and environmental scanning electron microscopy （ESEM）. The microstructure of highly filled PE/MH composites changed after the addition of functional polymers. The mechanical properties of the composite material increased after compatibilization. The compatibilization processes of PE-g-GMA and E/MA/GMA were different. The grafted polymer was more compatible with polyethylene, which led to a polar polymer phase. In contrast, the tercopolymer tended to adhere to the surface of MH particles.

Effect of Functionalized Multi-walled Carbon Nanotubes with Poly(N-vinyl pyrrolidone-co-2-acrylamido-2-methyl-1-propanesulfonic acid) on the Release of Tramadol Hydrochloride

Multi-walled carbon nanotubes （MWCNTs） were grafted with poly（N-vinyl-2-pyrrolidone） and with poly（2- acrylamido-2-methyl-1-propanesulfonic acid） at different compositions by using y-rays technique as initiator. The MWCNTs, MWCNT-graft-PNVP, MWCNT-graft-PAMPS and MWCNTs-graft-P（NVP-co-AMPS） were characterized by Fourier transform infra red （FTIR） spectroscopy, X-ray diffraction （XRD）, thermal gravimetric analysis （TGA）, elemental analysis and high-resolution transmission electron microscopy （HR-TEM）. The results indicated that the grafting processes of PNVP, PAMPS and P（NVP-co-AMPS） occurred on to the surfaces of MWCNTs without destroying the framework of MWCNTs. Tramadol hydrochloride （TH） was loaded as model drug and its release behavior was analyzed via various kinetic models. Release of the loaded TH was studied in simulated gastric fluid （SGF, pH = 1.2） and simulated intestinal fluid （SIF, pH = 7.4） at 37 ℃. Controlled release of TH from grafted MWCNTs was investigated. The outcome results suggest that the grafted MWCNTs could be used as a promising matrix candidate for oral drug delivery system by harmonization between the composition and pH level of the simulated biological fluids.