Methacryloxyethyltrimethyl Ammonium Chloride Research Articles

Preparation and antibacterial ability of photodynamic antibacterial nanoparticles with ammonium cationic groups

With the increasing infection of drug-resistant bacteria, it has become a great challenge for researchers to find new approaches to eradicate drug-resistant bacteria and their biofilms. Photodynamic antimicrobial chemotherapy (PACT) is an indispensable part of the new anti-bacterial strategy because of its unique anti-bacterial mechanism, which can effectively inactivate drug-resistant bacteria without inducing further drug resistance. In this work, nanoparticles with N-isopropylacrylamide and methacryloxyethyltrimethyl ammonium chloride as monomers, and loaded with a fluorescent conjugated polymer were successfully prepared by microemulsion polymerization. The average particle size ranged from 100 to 200 nm. The nanoparticles could disperse in water steadily according to their zeta potential analysis. The nanoparticles generated singlet oxygen upon exposing to light with wavelength of 500–700 nm. Their PACT efficiency was investigated against Escherichia coli, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus respectively. The results indicated that the antibacterial ability of nanparticles were excellent as the concentration was more than 0.01 mg/mL and the illumination time was 30 min. When the mass concentration of the nanoparticles was equal to or more than 0.05 mg/mL, the antibacterial mechanism was dominated by cation action, and when the concentration was equal or lower than 0.01 mg/mL, the antibacterial ability of the nanoparticles was improved effectively by photodynamic action. The antibacterial rate of the nanoparticle solutions against the bacteria in the biofilm was quantitatively studied, and it was proved that the nanoparticles eliminated bacteria in the biofilm effectively with a nanoparticle concentration of 0.2 mg/mL or more. The results indicated that the nanoparticles could effectively penetrate the biofilm to kill bacteria inside the biofilm by light illumination.

Multi-interface interaction mechanism of pulp reject-based flocculants for the removal of antibiotics and its combined pollutants

The efficient removal of antibiotics and its combined pollutants is essential for aquatic environment and human health. In this study, a lignin-based organic flocculant named PRL-VAc-DMC was synthesized using pulp reject as the raw material, with vinyl acetate (VAc) and methacryloxyethyltrimethyl ammonium chloride (DMC) as the grafting monomers. A series of modern characterization methods were used to confirm the successful preparation of PRL-VAc-DMC and elucidate its polymerization mechanism. It was found that the Ph-OH group and its contiguous carbon atoms of lignin served as the primary active sites to react with grafting monomers. Flocculation experiments revealed that PRL-VAc-DMC could react with tetracycline (TC) through π-π* interaction, hydrophobic interaction, hydrogen bonding, and electrostatic attraction. With the coexistence of humic acid (HA) and Kaolin, the aromatic ring, hydroxyl, and amide group of TC could react with the benzene ring, hydroxyl group, and carboxyl group of HA, forming TC@HA@Kaolin complexes with Kaolin particles acting as the hydrophilic shell. The increase in particle size, electronegativity, and hydrophily of TC@HA@Kaolin complexes facilitated their interaction with PRL-VAc-DMC through strong interfacial interactions. Consequently, the presence of HA and Kaolin promoted the removal of TC. The synergistic removal mechanism of TC, HA, and Kaolin by PRL-VAc-DMC was systematically analyzed from the perspective of muti-interface interactions. This paper is of great significance for the comprehensive utilization of pulp reject and provides new insights into the flocculation mechanism at the molecular scale.

Metal-Free Atom Transfer Radical Polymerization to Prepare Recylable Micro-Adjuvants for Dendritic Cell Vaccine.

In the development of dendritic cell (DC) vaccines, the maturation of DCs is a critical stage. Adjuvants play a pivotal role in the maturation of DCs, with a major concern being to ensure both efficacy and safety. This study introduces an innovative approach that combines high efficacy with safety through the synthesis of micro-adjuvants grafted with copolymers of 2-(methacrylamido) glucopyranose (MAG) and methacryloxyethyl trimethyl ammonium chloride (DMC). The utilization of metal-free surface-initiated atom transfer radical polymerization enables the production of safe and recyclable adjuvants. These micrometer-sized adjuvants surpass the optimal size range for cellular endocytosis, enabling the retrieval and reuse of them during the ex vivo maturation process, mitigating potential toxicity concerns associated with the endocytosis of non-metabolized nanoparticles. Additionally, the adjuvants exhibit a "micro-ligand-mediated maturation enhancement" effect for DC maturation. This effect is influenced by the shape of the particle, as evidenced by the distinct promotion effects of rod-like and spherical micro-adjuvants with comparable sizes. Furthermore, the porous structure of the adjuvants enables them to function as cargo-carrying "micro-shuttles", releasing antigens upon binding to DCs to facilitate efficient antigen delivery.

Metal‐Free Atom Transfer Radical Polymerization to Prepare Recylable Micro‐Adjuvants for Dendritic Cell Vaccine

AbstractIn the development of dendritic cell (DC) vaccines, the maturation of DCs is a critical stage. Adjuvants play a pivotal role in the maturation of DCs, with a major concern being to ensure both efficacy and safety. This study introduces an innovative approach that combines high efficacy with safety through the synthesis of micro‐adjuvants grafted with copolymers of 2‐(methacrylamido) glucopyranose (MAG) and methacryloxyethyl trimethyl ammonium chloride (DMC). The utilization of metal‐free surface‐initiated atom transfer radical polymerization enables the production of safe and recyclable adjuvants. These micrometer‐sized adjuvants surpass the optimal size range for cellular endocytosis, enabling the retrieval and reuse of them during the ex vivo maturation process, mitigating potential toxicity concerns associated with the endocytosis of non‐metabolized nanoparticles. Additionally, the adjuvants exhibit a “micro‐ligand‐mediated maturation enhancement” effect for DC maturation. This effect is influenced by the shape of the particle, as evidenced by the distinct promotion effects of rod‐like and spherical micro‐adjuvants with comparable sizes. Furthermore, the porous structure of the adjuvants enables them to function as cargo‐carrying “micro‐shuttles”, releasing antigens upon binding to DCs to facilitate efficient antigen delivery.

Flexible quasi-solid-state supercapacitors for anti-freezing power sources based on polypyrrole@cation-grafted bacterial cellulose

Polypyrrole (PPy)/cellulose nanofiber (CNF) composites have been widely used in flexible energy storage devices because of their lightweight, inherent mechanical flexibility and large specific surface area. However, it is still a challenge to obtain PPy/CNF composite electrodes with high cycling stability. Herein, an electrostatic self-assembly strategy was adopted to deposit anion-doped PPy onto cationic poly(methacryloxyethyltrimethyl ammonium chloride)-grafted bacterial cellulose (BCD) nanofibers. The optimized PPy@BCD electrode demonstrated a high areal capacitance of 6208 mF cm−2 at a current density of 0.5 mA cm−2 and superior cycling stability (a capacitance retention of 100 % after 10,000 charge-discharge cycles at 10 mA cm−2). A quasi-solid-state anti-freezing flexible supercapacitor (AF-FSC) was designed by employing polyacrylamide organohydrogel electrolyte, yielding an areal capacitance of 2930.6 mF cm−2 at 1 mA cm−2 and a capacitance retention of 92.2 % after 1000 cycles at −20 °C. The present AF-FSC is expected to serve as a power source in real-life low-temperature applications.

Synthesis of novel zwitterionic polymers and their properties as filtrate reducer for water‐based drilling fluid

AbstractThe development of high‐temperature and salt‐resistant filtrate reducer is of great significance to the exploitation of deep and ultra‐deep wells. In this study, Zwitterionic copolymer PANDS was synthesized by free radical polymerization using acrylamide (AM), N‐vinylpyrrolidone (NVP), methacryloxyethyl trimethyl ammonium chloride (DMC) and sodium p‐styrene sulfonate (SSS) as monomers. Through orthogonal test, the optimum synthesis conditions were determined as follows: n (AM): n (NVP): n (SSS): n (DMC) = 3.5:2:0.5:0.5, the reaction temperature is 50°C, the initiator concentration is 0.4 wt%. The structure and thermal stability of the copolymers were analyzed by Fourier transform infrared spectroscopy (FT‐IR), nuclear magnetic resonance spectroscopy (1H‐NMR) and thermogravimetry (TG). In addition, the filtration reduction performance of PANDS was evaluated according to the American Petroleum Institute (API) standard. The mechanism of reducing filtration loss was studied by laser particle size analysis, Zeta potential and scanning electron microscope analysis of mud cake. The results show that PANDS has good temperature resistance and good filtrate loss reduction. With the addition of 1.5%PANDS, the filtrate loss of drilling fluid is 8.7 mL after aging at 160°C for 16 h, and can resist 6 wt% NaCl and 1 wt% CaCl2.

Interaction between Amphoteric Polymer and Silicic Acid Tanned Leather

Silicic acid-based tanning system is an effective and promising chrome-free tanning technology, and it is urgent to develop compatible post-tanning processes. Fatliquoring is one of the key procedures to determine the quality of resulted leather and fatliquoring agents mainly play the role of an effective softer/ plasticizer in leather production. However, there is a mismatch between most commercial fatliquoring agents (mainly compatible with chrome tanned leather) and silicic acid tanned leather (named SATL). Herein, an amphoteric polymer emulsion (APE) was prepared by free radical polymerization using methacryloxyethyl trimethyl ammonium chloride (DMC), 2-acrylamido-2-methylpropanesulfonate (AMPS), lauryl methacrylate (LMA), dimethylaminoethyl methacrylate (DMAEMA) as monomers. And in order to improve the lubricating property, APE was further compounded with castor oil to obtain an amphoteric fatliquoring agent (named COAPE). Comprehensive characterization showed that the amphoteric (pI=8.22) and amphiphilic APE could reduce the surface tension of water to 38.6 mN/m. The fatliquoring process was controlled by ingenious regulation of pH based on isoelectric points (pIs) of APE and SATL. In the initial stage, the pH of the bath was adjusted to be lower than the pIs of APE and SATL, amphoteric polymer molecules could easily penetrate into SATL leather as they are all positively charged. While during the fixing stage, the pH of the bath was adjusted between the pIs of APE and SATL, so the electrostatic interaction between amphoteric polymer molecules and SATL leather, as well as the aggregation of amphoteric polymers can promote their combination synergistically. As a fatliquoring agent, the application of COAPE demonstrated that its absorpotion rate (90.5%) was much higher than anionic commercial fatliquoring agent (63.2%), thus imparting SATL leather better softness (6.5 mm), elongation at break (95.5%) and tensile strength (11.6 N/mm2). These findings therefore provided scientific basis and technical support for the application of amphoteric materials to silicic acid-modified collagen matrix and would promote the practical application of silicic acid-based chrome-free tanning technology

High-sensitivity humidity sensing of a U-shaped microfiber coated with porous methacryloxyethyl trimethyl ammonium chloride film.

We demonstrate an intensity-modulated humidity sensor based on a U-shaped microfiber coated with porous methacryloxyethyl trimethyl ammonium chloride (DMC) film. The high surface-to-volume ratios of the porous structure improve the interaction between the DMC film and water molecules, resulting in significantly enhanced sensitivity of the humidity sensor. In the humidity range of 34.0%RH to 50.0%RH, the humidity sensitivity of this microfiber sensor is up to 3.090dB/%RH, which is six times higher than that of other fiber humidity sensors. The humidity detection range can be adjusted with high humidity sensitivity (≥1.685d B/% R H) by controlling the microfiber diameter and bent diameter. Furthermore, this type of sensor has a fast recovery time of 0.023s and a response time of only 0.692s. This type of sensor has broad potential applications in chemical processing, medical diagnostics, instrument manufacturing, and so on.

Chitosan based radiation crosslinked and grafted matrix: An environment friendly adsorbent for dye uptake

The adsorption capacity of [2-(methacryloxy) ethyl] trimethylammonium chloride (MAETC) grafted-crosslinked chitosan (CRChitosan-g-MAETC) using ionizing radiation was evaluated for adsorption of anionic dyes namely Acid Blue-25 (AB25), Reactive Orange-16 (RO16) and Reactive Red-120 (RR120) from manufactured aqueous solutions. Effect of various experimental variables like dye concentration, pH, contact time duration, temperature and adsorption on adsorbent grafted to different extent on adsorption kinetics and on equilibrium adsorption was investigated. To understand the equilibrium adsorption of dyes on the adsorbent the data was fitted into Langmuir, Freundlich and Temkin adsorption isotherms while adsorption kinetics was examined using pseudo-first order, pseudo-second order and intraparticle diffusion kinetic models. It was observed that the adsorption of all the three anionic dyes studied was better explained by the Freundlich model. Adsorption extent of dye varied with number of charge sites on the dye molecule. The adsorption of all the three anionic dyes followed pseudo-second order kinetics. Thermodynamic parameters such as standard enthalpy (ΔHo), standard entropy (ΔSo) and standard free energy (ΔGo) were estimated. The radiation grafted cationic adsorbent showed promising adsorbent properties for removal of anionic dyes.

Synthesis of starch‐based flocculant by multi‐component grafting copolymerization and its application in oily wastewater treatment

AbstractThe grafting copolymerization of methacryloxyethyl trimethyl ammonium chloride (DMC), acrylamide (AM) and polyaluminum chloride (PAC) on starch was initiated by KMnO4, HIO4and H2SO4composite system. The modification of starch was combined its best attributes with those of inorganic and organic polymers and therefore enhanced the flocculation effect when it was used as flocculants by increasing the charge neutralization, adsorption bridging and aggregation ability. The main influence factors on oil removal ratio were investigated through orthogonal experimental design, and the optimal preparation conditions were obtained. The grafted copolymer was characterized through a series of physicochemical techniques (i.e., SEC‐MALS,13C MAS NMR,27Al NMR, FTIR, SEM, and TGA and XRD), which indicated the PAC, PAM and PDMC were successfully grafted on the starch.

A Hydrophilic Strong Anion-Exchange Hybrid Monolith for Capillary Liquid Chromatography

A hydrophilic strong anion-exchange monolithic hybrid column was prepared by in-capillary coating 5-µm bare silica particles with the copolymers of methacryloxyethyltrimethyl ammonium chloride and pentaerythritol triacrylate in the presence of a porogen consisting of water, methanol, and cyclohexanol. The composition of the porogen and the concentration of the monomers were investigated and selected. The resulting column was characterized. The column had an uniform pore structure and could withstand a back pressure up to 3500 psi. Its permeability was comparable to that of packed columns and the swelling-shrinking behaviour negligible. Its hydrophobicity could be suppressed at acetonitrile concentrations above 40% (v/v) and the minimum theoretical plate height was about 10 µm for BrÑ. The column-to-column relative standard deviations (RSDs) were 2.2% and 3.5% (n = 9) and the batch-to-batch RSDs were 2.4% and 5.5% (n = 3) for k and H values, respectively. The column exhibited a remarkable performanceforthe separation of inorganic anions, organic weak acids, phenols, and nucleotides.

Design of novel temperature-resistant and salt-tolerant acrylamide-based copolymers by aqueous dispersion polymerization

ABSTRACT Development of polymer-based flooding technology to improve oil recovery efficiency, water dispersion copolymerization of acrylamide, cationic monomer methacryloxyethyltrimethyl ammonium chloride (METAC), and anionic monomer acrylic acid (AA) were carried out in aqueous ammonium sulfate solution with polyvinyl pyrrolidone (PVP) as the stabilizer. The copolymers were characterized by 1H-NMR, FT-IR, TG, and SEM to confirm that they were prepared successfully and exhibited excellent salt-resistant property. Moreover, the effect of the aqueous solution of ammonium sulfate (AS) concentration, stabilizer concentration, and initiator concentration on the viscosity and size were systematically investigated. To further improve the thermal endurance properties of copolymer, hydrophobic monomers with different alkyl chain lengths were added to the above system. The acrylamide-based quadripolymer possessed prominent thermal and salt endurance properties by utilizing the advantages of zwitterionic structure and hydrophobic monomer. With the temperature rising, the viscosity retention could reach 70.2% in the water and 63.8% in the saline. This work had expected to provide a new strategy to design polymers with excellent salinity tolerance and thermal-resistance performances.

Effect of tiny amount of DMC on thermal, mechanical, optical, and water resistance properties of poly(vinyl alcohol)

Abstract In this paper, tiny amount of methacryloxyethyl trimethylammonium chloride (DMC) was added in poly(vinyl alcohol) (PVA) in order to widen its thermoplastic processing window. The effects of DMC content on thermal, mechanical, optical, and water resistance were investigated. The results showed that the thermal stability of PVA/DMC was improved obviously. Compared with pure PVA, with tiny amount (∼0.6 wt%) of DMC, the initial decomposition temperature and the fastest decomposition temperature of DMC/PVA increased from 246 °C and 287.6 °C–320.8 °C and 364.8 °C respectively. Moreover, this tiny amount of DMC did not affect the crystallization performance of PVA. PVA/DMC (0.6 wt%) blend have similar mechanical, optical properties and low temperature water resistance as those pure PVA have. The melting temperature of the PVA/DMC remained at 221 °C as that of pure PVA. This work might provide a new method for widening the thermoplastic processing window of PVA without sacrificing its other inherent properties. The reasons why DMC could improve the thermal stability for PVA was explored as well.

Preparation of a novel zwitterion flocculant with the characteristics of quaternary ammonium salt cation and dithiocarbamate anion and its application in produced water treatment

In this paper, a novel flocculant with the characteristics of both quaternary ammonium salt cation and dithiocarbamate anion was synthesized. Firstly, a cationic polymer having secondary amine side groups was synthesized by using cationic monomer and diallyl amine (DAA) as monomers via aqueous solution polymerization, and then the secondary amine was modified by carbon disulfide (CS2) to prepare the zwitterion flocculant. By using the oil removal as index, the effects of cationic monomer type, monomer concentration, mass ratio of cationic monomer to DAA, initiator concentration, polymerization temperature and time on the copolymerization results were investigated. The recommended rational condition was as follows: cationic monomer was methacryloxyethyltrimethyl ammonium chloride (DMC), monomer concentration was 50 wt%, mass ratio of DMC:DAA = 4:1, initiator was ammonium persulfate (APS) and its concentration was 0.4 wt%, and polymerization temperature was 60 °C for 8 h. The zwitterion flocculant obtained at the recommended condition had a removal of 99.5% at the dosage of 300 mg/L for produced water obtained from an offshore oilfield. In addition, the flocculation mechanism of the zwitterion flocculant was studied. According to the results of zeta potential measurement and floc morphology, it can be found that the quaternary ammonium salt unit in the zwitterion flocculant can bridge and flocculate oil droplets by destroying the stability of oil droplets in produced water through electrostatic neutralization, while the dithiocarbamate unit can interact with Fe2+ in produced water to form a network structure to catch flocculated oil droplets, and the synergistic effect of quaternary ammonium salt unit and dithiocarbamate unit is helpful for achieving the good flocculation result. The results provide a new selection for produced water treatment.

Synthesis of a Superhydrophobic Fluorinated Nano-Emulsion and Its Modification on the Wettability of Tight Sandstone.

The water-blocking effect is a serious problem when developing tight sandstone gas reservoirs, which can cause a sharp reduction in gas production. Wettability alteration of near-wellbore sand rock surface from superhydrophilicity to superhydrophobicity is an effective method to decrease capillary pressure. In this study, a superhydrophobic fluorinated nano-emulsion was synthesized via a soap-free emulsion polymerization process using methacryloxyethyl trimethyl ammonium chloride, trifluoctyl methacrylate, and styrene as monomers. The effect of the fluorinated monomer concentration on wettability alteration was evaluated by measuring the contact angle of the formation water droplet on the modified glass slides using nano-emulsions with different fluorinated monomer concentrations. The results showed that the nano-emulsion had a good dispersibility and homogeneous particle size of around 90 nm, and with the increase in fluorinated monomer concentration, the contact angle increased. The contact angle was the largest when the fluorinated monomer mass rate concentration reached 50%. The adsorption of nanoparticles could alter the rock wettability from a super hydrophilic state (θ = 7°) to a superhydrophobic state (θ = 150°). The spontaneous imbibition experiments showed that the formation water adsorption quality of the core decreased by 49.7% after being modified by the nano-emulsion. The nano-emulsion showed a good superhydrophobicity and had the potential to be used to reduce the water-blocking damage in the tight gas reservoirs.

Single and competitive adsorption between Indigo Carmine and Methyl orange dyes on quaternized kapok fiber adsorbent prepared by radiation technique

Since industrial effluents contain several dye species, investigation on the competitive adsorption and selective adsorption mechanism is quite necessary. In this paper, single and competitive adsorption of Indigo Carmine (IC) and Methyl Orange (MO) dyes using methacryloxyethyltrimethyl ammonium chloride functionalized kapok fiber (DKF) were investigated. The maximum adsorption capacity of individual adsorption was 1011.3 mg/g and 1079.9 mg/g for MO and IC, respectively. However, IC has significant inhibitory effect on MO uptake but IC adsorption almost not change in binary system, which is in contrast to the reported results that competitive adsorption capacity was greatly reduced for each dye in binary system. The separation factor of IC/MO could reach 129.53 when the concentration of IC and MO equal 0.2 mol/L, indicating good selectivity toward IC. The selective adsorption mechanism between MO and IC was attributed to the displacement impact. Therefore, this work provided a potential adsorbent for selectively removing dye from industrial effluents and give a new sight to the competitive adsorption mechanism among dyes.

Facile Synthesis of Hydrogel-Based Ion-Exchange Resins for Nitrite/Nitrate Removal and Studies of Adsorption Behavior.

This research aimed to create facile, reusable, hydrogel-based anion exchange resins that have been modified with two different amines to test their ability to adsorb nitrate and nitrite in water using batch and continuous systems. In the batch experiment, maximum adsorption capacities of nitrate and nitrite onto poly (ethylene glycol) diacrylate methacryloxyethyltrimethyl ammonium chloride (PEGDA-MTAC) and poly (ethylene glycol) diacrylate 2-aminoethyl methacrylate hydrochloride (PEGDA-AMHC) adsorbents can be obtained as 13.51 and 13.16 mg NO3−-N/g sorbent; and 12.36 and 10.99 mg NO2−-N/g sorbent respectively through the Langmuir isotherm model. After 15 adsorption/desorption cycles, PEGDA-MTAC and PEGDA-AMHC retained nitrate adsorption efficiencies of 94.71% and 83.02% and nitrite adsorption efficiencies of 97.38% and 81.15% respectively. In a column experiment, modified adsorbents demonstrated adsorption efficiencies greater than 45% after being recycled five times. Proposed hydrogel-based adsorbents can be more effective than several types of carbon-based sorbents for nitrate and nitrite removal in water and have benefits such as reduced waste generation, cost-effectiveness, and a facile synthesis method.

Catalytic Activity Comparison of Gold Nanoparticles in Annealed and Quenched Spherical Polyelectrolyte Brushes

Abstract Two kinds of cationic spherical polyelectrolyte brushes (SPB), quenched poly(methacryloxyethyltrimethyl ammonium chloride) brush and annealed poly(2-aminoethyl methacrylate hydrochloride) brush with polystyrene cores (PS-PMETAC and PS-PAEMH), were synthesized by photo-emulsion polymerization. The small and uniform gold nanoparticles (AuNPs) were successfully immobilized in these two SPBs. The chain layer extension of the quenched SPB loaded with AuNPs (SPB-Au) was more complete than that of the annealed SPB-Au in alkaline system. Compared the catalysis of the prepared AuNPs onto the two SPBs, it was found that the catalytic activity of AuNPs in quenched SPB is higher than that in annealed SPB.

Chlorine-resistant positively charged polyamide nanofiltration membranes for heavy metal ions removal

Heavy metal pollution is one of the most serious environmental problems. Nanofiltration (NF) is an effective and potential membrane separation technology for removal of heavy metal ions from water. However, the separation performance and chlorine resistance of NF membranes should be further improved in industry. Herein, to obtain exceptional water permeability and chlorine resistance, novel positively charged polyamide (PA-PDMC) NF membranes were fabricated by surface-initiated atom transfer radical polymerization (SI-ATRP), through which methacryloxyethyltrimethyl ammonium chloride (DMC) was grafted to the 2-bromoisobutyryl bromide (BIBB) exposed on the surface of polyamide (PA-Br1) membrane. The graft length of positively charged polymer chains were controlled by ATRP time, which furtherly exerted influences on the surface structures and properties of PA-PDMC membranes. At the optimal graft content, the retentions to MgCl2, CaCl2, CuCl2, ZnCl2 of the as-prepared PA-PDMC membrane were 92.8%, 90.8%, 93.5% and 96.8% respectively with the flux of 82.5 L m−2 h−1, which maintained stability during the long-term operation process of 168 h. Moreover, the PA-PDMC membrane exhibited exceptional chlorine resistance at the chlorination condition of 12,000 ppm h.

Experimental investigation of a low-molecular-weight polymer coating agent for deep-sea oil and gas drilling

In order to solve the problems due to the thickening of drilling fluids at low temperatures caused by the use of high-molecular-weight polymer coating agents in offshore deep-sea oil and gas drilling, a low-molecular-weight polymer coating agent named PADA was synthesized with acrylamide, methacryloxyethyltrimethyl ammonium chloride, and 2-acrylamido-2-methyl propane sulfonic acid. The PADA polymer was characterized with Fourier transform infrared spectroscopy and gel permeation chromatography. The shale inhibition effects of the PADA polymer and associated mechanisms were investigated by shale recovery and expansion experiments, transmission electron microscopy observation, particle size and zeta potential analysis, and interlayer spacing measurements. In addition, the effects of the coating agent on the filter cakes and the low temperature rheological properties of bentonite mud were also tested, and the polymer biodegradability was evaluated. The results showed that the molecular weight of the PADA polymer was 265,000 D, which was significantly lower than that of the traditional coating agents. The PADA had similar effects as two typical commercial products CAP and HPAM on inhibiting the hydration dispersion of shales and performed better than another product PAM. The inhibition effect was achieved by the polymer absorption onto the clay particles through both hydrogen bonding and the electrostatic interactions. The viscosity of bentonite mud containing PADA was much lower than that of mud with other coating agents at 4 °C, so the serious thickening caused by traditional coating agents at a low temperature could be avoided. In addition, it is relatively easily biodegraded.