Sodium Methylallyl Sulfonate Research Articles

Effects of crosslinked polycarboxylate superplasticizers with crosslinking agent containing ester and amide groups on the properties of cementitious systems

AbstractHerein, crosslinked polycarboxylate superplasticizers were synthesized using acrylic acid, sodium methylallyl sulfonate and methyl polyethylene glycol acrylate as monomers, and monomers that contain either ester or amide groups as crosslinking agents. The superplasticizers that were synthesized from the ester‐ and amide‐based crosslinking agents were respectively denoted as SP‐E and SP‐N. In addition, a series of performance characterizations were carried out to explore the influence of different functional groups in crosslinking agents on the performance of superplasticizers. Fluidity test results showed that the dispersibility and fluidity retention of cement pastes treated with the SP‐E were better than those of cement pastes treated with SP‐N. Meanwhile, the viscosity of the sample containing SP‐E was lower than that containing SP‐N. In addition, the amount of the two superplasticizers that had become adsorbed onto the surfaces of cement particles also differed, and in this case the adsorption capacity of SP‐E was greater than that of SP‐N. X‐ray diffraction, thermogravimetric analysis, and scanning electron microscopy tests showed that the ester‐group based SP‐E superplasticizers promoted cement hydration to a greater degree than that was achieved with their amide‐bearing SP‐N counterparts. This study would provide valuable insight for the development of crosslinked polycarboxylate superplasticizers.

Synthesis and rapid cement hardening evaluation of polycarboxylate superplasticizers incorporating ester groups in their backbone chain

AbstractA new water‐soluble, hydrolyzable polyethylene glycol di‐mercaptoacetate (PGM) was synthesized as a chain transfer agent. Subsequently, an early‐strength polycarboxylate superplasticizer (ESPC) was successfully prepared by using PGM as a chain transfer agent, along with acrylic acid, sodium methylallyl sulfonate (SMAS), and isoprene oxy poly(ethylene glycol) as comonomers. The effect of the ESPC on cement particles was systematically investigated. The fluidity, setting time, and compressive strength were measured to evaluate the performance of the ESPC and compared with those of a conventional polycarboxylate superplasticizer (PCE). The setting time of the ESPC can be shortened by 40 min in comparison with the PCE, and the compressive strength at 24 hr of setting time is increased by 5 MPa. In addition, X‐ray diffraction, thermogravimetric analysis, and scanning electron microscopy characterization were performed to investigate the effect of the ESPC on cement hydration from a microscopic level. Furthermore, the hydration heat was determined to investigate the interactions between the ESPC with the cement particles. It was found that if ester groups were introduced into the backbone chain of the ESPC and subsequently hydrolyzed, the ESPC was readily adsorbed onto cement particles. This enhanced adsorption improved the microstructure of the cement hydrate and accelerated the cement hydration process.

A comparative study on impact factors of emission: surface state, carbonaceous core, and size based on series of exactly designed P, S co-doped carbon dots

Heteroatoms, such as nitrogen, sulfur, and phosphorus, in surface state dedicate the passivation layer, which along with the structure of carbonaceous core (the size of conjugated sp2 domains) and diameter in carbon dots affect the emission. To disclose the dominant one among them, two series of well-designed P, S co-doped carbon dots (P/S-CDots) possessing different particle sizes and individual chemical structures both in surface and core were prepared. As results, the concentration of sp2 hybrid carbon atom in carbonaceous core plays the vital role in effecting the photoluminescence efficiency of carbon dots by determining the optical-harvesting ability, followed by heteroatom’s doping amount. Besides, phosphorus is superior to sulfurs regarding to improving the photoluminescence efficiency based on the calculated results of LUMO-HOMO gap. It is worth mentioning that the copolymer as precursor is very qualified in the paper, because that the structure and diameter of P, S-CDots are easy to be manipulated by managing the chain structure and molecular weight of it, which is a terpolymer prepared by free radical polymerization using acrylic phosphate, sodium methylallyl sulfonate, and acrylic acid as monomers in the presence of ammonium persulfate.

Comb‐like polymer with sulfo groups and its dispersion and rheological properties in aqueous ceramic suspensions

ABSTRACTTwo types of new comb‐like polymers were formed as dispersants for aqueous ceramic suspensions with isoprenyloxy poly(ethylene glycol ether), acrylic acid, maleic anhydride as the main starting materials. During the synthesis, one comb‐like polymer introduced sodium methylallyl sulfonate (SMAS) into the reaction media, whereas the other did not. The chemical structure and molecular weight were characterized by Fourier transform infrared spectroscopy and gel permeation chromatography. The effects of the polymers on the dispersion, ζ potential and rheological properties of the kaolin suspensions are discussed in detail. The results indicate that SMAS facilitated chain transfer, controlled the effective charge density of the surface, and increased the electrostatic repulsion force. The kaolin suspensions displayed shear‐thinning behavior on the basis of the electrostatic and steric effects of the comb‐like polymers. The apparent viscosity decreased from 1088 to 258 mPa s with the assistance of the SMAS‐prepared comb‐like polymer as a dispersant. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44563.

Study on dispersion, adsorption and flow retaining behaviors of cement mortars with TPEG-type polyether kind polycarboxylate superplasticizers

This paper highlighted the study on dispersion, adsorption and flow retaining behaviors of cement mortars with TPEG-type polyether kind polycarboxylate superplasticizers (PCEs) which were synthesized by isoprenyl oxy polyethylene glycol ether (TPEG), acrylic acid (AA), maleic anhydride (MA) and sodium methylallyl sulfonate (SMAS). These copolymers were characterized by FT-IR, 1H NMR and GPC. The effects of TPEG-type PCEs on fluidity and flow retention, adsorption and zeta potential in cement mortars were detailed discussed, and the dispersion and adsorption mechanism was compared with conventional MPEG-type polyester kind PCEs. Experimental results indicated that the MA modified TPEG-type PCE2 with certain number of anchor groups and PEO side chains has excellent water reducing capability and flow retaining ability, which is mainly attributed to the maximum synergistic effects of steric hindrance and electrostatic repulsive force. Further application results indicated that PCE2 can be used as high-range water reducer to produce high performance concrete.

Synthesis and properties of an AMPS-modified polyacrylic acid superplasticizer

A 2-acrylamide-2-methyl propylene sodium sulfonic (AMPS)-modified polyacrylic acid superplasticizer was synthesized using aqueous solution polymerization with the major monomers including the self-made active macromers polyethylene glycol mono-methyl ether acrylate acrylic (MPEGAA), acrylic acid (AA), AMPS, and sodium methyl allyl sulfonate (SMAS). The ratios of the monomers were determined using an orthogonal experiment. This research focused on the effects of the dosages of different macromers, the polymerization conditions, and the length of MPEGAA side chains on the properties of the AMPS-modified polyacrylic acid superplasticizer. The best polymerization conditions of the AMPS-modified polyacrylic acid superplasticizer are when (n(MPEGAA):n(SMAS):n(AMPS):n(AA) equals 0.1:0.1:0.2:0.65, the molecular weight of monomethoxypolyethylene glycol is 1 200, the initiator ammonium persulfate accounts for 5% of the total mass of the polymerized monomers, the polymerization temperature is 80 °C, and the reaction time is 4 h. The AMPS-modified polyacrylic acid superplasticizer synthesized in the best conditions exhibited excellent dispersivity and dispersion retainability. When the dosage ratio was 0.24%, the initial fluidity was 400 mm and the fluidity had nearly no loss after 1 h.

Study on Relationship between Structure and Properties of Polycarboxylate Superplasticizer

A polycarboxylate superplasticizer (PCs) was synthesized by copolymerization of allyl polyoxyethylene ethers (APE), acrylic acid (AA), sodium methylallyl Sulfonate (SMAS) and ethyl acrylate (EA). The effect of functional groups and branch chain on PCs properties was investigated by the test of fluidity of cement paste, retardation performance and Zeta potential of cement particles. The results showed that carboxylic groups and ethyl ester groups can improve water reducing ratio and fluidity of cement paste, and the sulfonic groups has an important contributiion to retardation performance of PCs.

Preparation and Properties of Polycarboxylate Superplasticizer with Hydroxy Terminated Side Chains

Maleic anhydride modified polycarboxylates superplasticizes (MPC) was synthesized from allylic poly (ethylene oxide ether) (APEG), maleic anhydride (MAH), sodium methylallyl sulfonate (SMAS) using ammonium persulfate (APS) as initiator. The optimal MPC with best fluidity was got at 90 °C when molar ratio of MAH, APEG, SAMA was 2.75∶1∶0.4 in the present of 4.5 mol% APS of all the monomer molars. MPC which possessed hydroxyl terminated side chains shows some difference in fluidity retarding related to the conventional superplasticizers possessed methoxy terminated side chains.

Determination of residual monomers in polycarboxylate superplasticizer using high performance liquid chromatography

A procedure was developed for the determination of residual monomers in polycarboxylate superplasticizer (PCs) by reversed-phase high performance liquid chromatography (RP-HPLC). Four kinds of residual monomers were well separated and determined on a SinoChrom ODS-BP (C18) column with mobile phases composed of acetonitrile and phosphate buffer solution. The monomers were detected by UV detector at 205 nm and quantitatively analyzed with an external standard method. For those residual monomers, the linear response ranged from 4.0×10−6 mol·L−1 to 2.0×10−3 mol·L−1. The determination limit of acrylic acid, sodium methylallyl sulfonate and 2-Acrylamido-2-methylpropane sulfonic acid was 0.02×10−5 mol·L−1, while that of methoxy-polyethylene glycol monoacrylate was 0.1×10−5 mol·L−1. The relative standard deviation (RSD) of high concentration samples was less than 1%, while that of the low concentration samples was between 1%–4%. The standard (additional) recovery ratio was 97.4%–104.2%.

Synthesis and characterization of poly(acrylic acid‐co‐acrylamide)/hydrotalcite nanocomposite hydrogels for carbonic anhydrase immobilization

AbstractTo combine the advantages of a biopolymer with hydrotalcite in an enzyme immobilization system, the intercalation polymerization was used to prepare poly(acrylic acid‐co‐acrylamide)/hydrotalcite (PAA‐AAm/HT) nanocomposite hydrogels using sodium methyl allyl sulfonate as intercalation agent. Transmission electron microscopy, X‐ray diffraction, and Fourier transform infrared spectroscopy results revealed that sodium methyl allyl sulfonate chains entered into the interlayer of HT, the interaction between them has taken place, and HT was dramatically exfoliated into nanoscale and homogeneously dispersed in the PAA‐AAm matrix. Transmission electron microscopy and cryo scanning electron microscope results showed that dried hydrogels were regular spherical particles, and swollen hydrogels revealed homogeneous porous network structures. Then, PAA‐AAm/HT nanocomposite hydrogels were used to immobilize carbonic anhydrase (CA), and the CO2 hydration activities of free enzyme and immobilized enzyme were evaluated. Results showed that immobilized CA retained the majority of the enzyme activity. The reason may be the formation of a microenvironment almost all of which is composed of free water inside the porous network structures. Therefore, the immobilized CA is of great potential in the removal of trace CO2 from the closed spaces. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3232–3240, 2009

Preparation and morphology of high‐performance exfoliated poly(sodium acrylate)/hydrotalcite nanocomposite superabsorbents

AbstractA poly‐matrix composite—poly(sodium acrylate) (PSA)/hydrotalcite (HT) (PSA/HT) nanocomposite superabsorbent—with obvious improvements in both the water absorbency and salt absorbency has been prepared by the intercalated HT, using sodium methyl allyl sulfonate as an intercalation agent. The superabsorbents acquired their highest water (salt) absorbency when the content of HT is 3 wt%. The highest absorbency for deionized water and 0.9 wt% NaCl (aq) were 1100 g/g and 145 g/g, respectively. Microstructures were analyzed by X‐ray diffraction and scanning electron microscope. Chemical analysis was determined measurements. Results showed that HT incorporated into the superabsorbents was by Fourier infrared spectroscopy and energy dispersion spectroscopy. Results showed that the superabsorbent particles were in the form of spheres, and the hydrogels were in the form of regular network structures. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers

Hyperbolic method to analyze the electrical resistivity curve of Portland cements with superplasticizer

The effects of structure parameters, such as molecular structure, segment kinds, molecular weight, and organic functional groups, on the performance of polyacrylic acid superplasticizer were discussed. According to the differences of chain sections, functional groups, etc, polyacrylic acid superplasticizer could be divided into A, B, C three parts. Among them, A chain section included sulfonic acid groups, B chain section carboxyl groups, C chain section polyester. Polyacrylic acid superplasticizers with different matching of A, B, C chain sections, different length of C chain section and different molecular weights were synthesized by acrylic acid, polyethylene glycol, sodium methyl allylsulfonate; the relation between the molecular structure and performance was also studied. The expetimental results indicate that the water-reduction ratio increases obviously with the increment of the proportion of sodium methyl allylsulfonate chain section in the molecular; the slump retention increases greatly with the increment of the proportion of acrylic acid chain section; the dispersion of cement particles increases with the increment of the chain length of polyethylene glycol; when the molecular weight is in the range of 5000, the dispersion and slump retentibity increase with the increment of the average molecular weight of polymers.

Preparation of nanocomposite superabsorbents based on hydrotalcite and poly(acrylic-co-acrylamide) by inverse suspension polymerization

Firstly, hydrotalcite (HT) was synthesized by the urea method. Then, sodium methyl allyl sulfonate (SMAS) was used as intercalation agent to prepare intercalated HT (SMAS–HT). Finally, a novel poly(acrylic-co-acrylamide)/HT nanocomposite superabsorbent was prepared by inverse suspension polymerization, using N,N′-methylenebisacrylamide (NMBA) as a cross-linking agent and potassium persulfate (KPS) as an initiator. The morphology of the superabsorbents was characterized by FT-IR, XRD, SEM and TEM. The influences of the amount of SMAS–HT on the water (salt) absorbency were investigated. Results showed that the intercalation was successful and the intercalated SMAS–HT incorporated into the superabsorbent was completely exfoliated. The superabsorbent particles approach a spherical shape and the average size is 200–300 nm. The particle sizes of the superabsorbents decrease with increasing the content of SMAS–HT. In addition, the superabsorbent acquired its highest water (salt) absorbency when the content of SMAS–HT is 3 wt%. The highest absorbencies of the superabsorbent for deionized water and 0.9% NaCl(aq) were 900 g/g and 140 g/g, respectively.