Preparation and Cement Fluidity of Slow-Release Polycarboxylate-Type Superplasticizer

2011 ◽  
Vol 399-401 ◽  
pp. 1307-1311 ◽  
Author(s):  
Xia Lv ◽  
Cheng Bing Yu ◽  
Wen Ying Qi
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Acrylic Acid ◽  
High Performance ◽  
Slow Release ◽  
Thioglycolic Acid ◽  
Ammonium Persulfate ◽  
Allyl Ether ◽  
Molecular Weight Regulator

High performance polycarboxylate-type superplasticizer (PCSP) was synthesized with acrylic acid (AA), polyethylene glycol allyl ether (APEG) and one monomer of methyl acrylate (MA), methacrylate acid (MAA), acrylamide (AM), and ethyleneglycol dimethacrylate (EGDMA). Ammonium persulfate and thioglycolic acid, as an initiator and a molecular weight regulator respectively, were used for radical polymerization in aqueous solution. Influence of superplasticizer on the cement fluidity of grout was investigated. The results showed that plasticizer admixture compounded with EGDMA-APEG-AA had excellent dispersibility and slump retention.

Preparation and Characterization of Kenaf-Based Superabsorbent Polymers

2011 ◽  
Vol 183-185 ◽  
pp. 1812-1816
Author(s):  
Dan Wang ◽  
Zhan Qian Song ◽  
Shi Bin Shang ◽  
Zhan Jun Wang ◽  
Myoung Ku Lee
Keyword(s):  
Aqueous Solution ◽  
Acrylic Acid ◽  
Graft Copolymerization ◽  
Ph Value ◽  
Crosslinking Agent ◽  
Ammonium Persulfate ◽  
Deionized Water ◽  
Superabsorbent Polymers ◽  
Saline Solutions

Novel kenaf-based superabsorbent polymers (SAPs) were prepared by grafting acrylic acid (AA) and acrylamide (AM) onto kenaf cellulose. Graft copolymerization was carried out in aqueous solution using N, N’-methylenebisacrylamide (NMBA) as crosslinking agent and sodium bisulfite (NaHSO3) and ammonium persulfate ((NH4)2S2O8) as initiator. The SAPs so obtained were examined by SEM. The absorbency of SAPs consists of different kenaf cellulose in deionized water, saline solutions and different pH value solutions were investigated.

Dispersion Polymerization of Acrylamide and Acrylic Acid in Aqueous Media

2009 ◽  
Vol 87-88 ◽  
pp. 233-238
Author(s):  
Jiao Lu ◽  
Bo Peng ◽  
Ming Yuan Li ◽  
Mei Qin Lin
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Acrylic Acid ◽  
Intrinsic Viscosity ◽  
Salt Concentration ◽  
Apparent Viscosity ◽  
Dispersion Polymerization ◽  
Aqueous Media ◽  
Salt Solutions ◽  
Aqueous Salt Solutions

Dispersion polymerization of acrylamide and acrylic acid was successfully carried out in aqueous salt solutions using anionic polyelectrolytes as stabilizers. The influences of aqueous solution of salt concentration, molecular weight and concentration of the stabilizers on the apparent viscosity and stability of the dispersions, and on the molecular weight of the polymers prepared were investigated. The results showed that stable dispersions could be obtained on condition that salt concentration was between 26%~30%, concentration of stabilizers between 8%~12%, and intrinsic viscosity of stabilizers between 2.977~3.740 dL/g. With salt concentration ranging from 26% to 30%, molecular weight of products increased first and then decreased. Molecular weight of products was hardly changed when concentration of stabilizer was between 8%~12%. When intrinsic viscosity of stabilizer was between 2.977~3.740 dL/g, increase of the molecular weight of stabilizer resulted in a decrease in the molecular weight of the products.

Synthesis and Characterization on a Kind of Polycarboxylate Superplasticizer

2014 ◽  
Vol 989-994 ◽  
pp. 228-232
Author(s):  
Xing Li ◽  
Guang Jun Zheng ◽  
Yao Bi ◽  
Cheng Fei Fu ◽  
Ming Hua Yuan ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Acrylic Acid ◽  
Chain Transfer ◽  
Thioglycolic Acid ◽  
High Water ◽  
Ammonium Persulfate ◽  
Synthesis And Characterization ◽  
Polyoxyethylene Ether ◽  
Polycarboxylate Superplasticizer ◽  
Gel Permeation

This study was undertaken to evaluate a new kind of polycarboxylate superplasticizer .Used polyoxyethylene ether (TPEG), acrylic acid (AA) as the monomer, ammonium persulfate (APS) as initiator, thioglycolic acid (TGA) as chain transfer agent, synthesised polycarboxylate superplasticizer with high water reducing rate. The effect of admixtures on fluidity and concrete slump were discussed in this paper. The structure of carboxylic acid water reducing agent was characterized by IR spectra and Gel permeation chromatography.This investigation also evaluated the influence of different serials of polyoxyethylene ether (TPEG), the dosage of acrylic acid (AA) and ammonium persulfate (APS).

Effects of the Carboxyl Density on the Properties of Polycarboxylate-Type Superplasticizer

2014 ◽  
Vol 989-994 ◽  
pp. 151-155
Author(s):  
Cheng Fei Fu ◽  
Guang Jun Zheng ◽  
Kang Ling Li ◽  
Yao Bi ◽  
Long Xiong
Keyword(s):  
Molecular Weight ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Acrylic Acid ◽  
Weight Distribution ◽  
High Performance ◽  
Gel Permeation Chromatography ◽  
Monomer Conversion ◽  
Cement Pastes ◽  
Gel Permeation

The effect of carboxyl density (the ratio of acrylic acid and polyoxyethylene ether) upon the performance, molecular weight, and monomer conversion rate of polycarboxylate (PCE) were investigated by slump test, Gel Permeation Chromatography (GPC) and High Performance Liquid Chromatography (HPLC), respectively. The results showed that with carboxyl density increased from 2:1 to 7:1, molecular weight of PCE increased from 7968.5 to 13930.1 and the molecular weight distribution coefficient increased from 1.5 to 2. The HPLC date indicated carboxyl density does not affect the rate of monomer conversion. Test of the fluidity of cement pastes displayed that as carboxyl density was 4.0:1, PCE show the optimal dispersion and dispersion-retaining ability.

Complex formation between poly(acrylic acid) and pyrene-labeled polyethylene glycol in aqueous solution

1987 ◽  
Vol 20 (3) ◽  
pp. 474-480 ◽  
Author(s):  
Hideko Tamaru Oyama ◽  
Wing T. Tang ◽  
Curtis W. Frank
Keyword(s):  
Aqueous Solution ◽  
Polyethylene Glycol ◽  
Complex Formation ◽  
Acrylic Acid ◽  
Poly Acrylic Acid

Preparation and Properties of New Polycarboxylate-Type Superplasticizer

2011 ◽  
Vol 194-196 ◽  
pp. 1122-1125
Author(s):  
Sheng Hua Lv ◽  
Rui Jun Gao ◽  
Jian Ping Duan ◽  
Xiao Liang Yan ◽  
Ming Ming Hou
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Maleic Anhydride ◽  
Sulfonic Acid ◽  
Setting Time ◽  
Monomethyl Ether ◽  
Ammonium Persulfate ◽  
Molar Ratio ◽  
Glycol Monomethyl Ether ◽  
Relative Molecular Weight

A modified polycarboxylate superplasticizer was synthesized by copolymerization of polyethylene glycol monomethyl ether methacrylate (MPEG-MA), β–Cyclodextrins grafted maleic anhydride (MAH-β-CD), methacrylic acid (MAA) and methallyl sulfonic acid (MAS). The excellent superplasticizer was obtained at the molar ratio of n(MAH-β-CD) : n(MAS) : n(MAA) : n(MPEG-MA) was 0.05:0.1:3:1 using ammonium persulfate (APS) as initiator at 90°C for 5 h. The applied results show that the product had many advantages, such as lower dosage, longer setting time, better flow-keeping ability and better compatibility with different cement. Meanwhile, the structure and relative molecular weight were characterized by FTIR and GPC respectively.

Polycarboxylate-Lignosulfonate Copolymerized High Performance Water Reducing Agent: Preparation and Application

2013 ◽  
Vol 687 ◽  
pp. 435-442 ◽  
Author(s):  
Zhen Ping Sun ◽  
Lei Zhao ◽  
Xiong Rong Huang ◽  
Hui Yang ◽  
Liang Liang Shui
Keyword(s):  
Aqueous Solution ◽  
Polyethylene Glycol ◽  
Methacrylic Acid ◽  
High Performance ◽  
Reducing Agent ◽  
Engineering Applications ◽  
Glycol Methacrylate ◽  
Sodium Methyl ◽  
Methoxy Polyethylene Glycol

A new polycarboxylate-lignosulfonate copolymerized high performance water reducing agent (PCL) was synthesized by polymerizing self-made methoxy polyethylene glycol methacrylate (MPEGMA), methacrylic acid (MAA), lignosulfonate (LS) and sodium methyl acryl sulfonate (SMAS) in aqueous solution. Influence of LS dosage used in synthesis on the performance of the product was investigated. The performance of the new polymer and compounds prepared by polycarboxylate based superplasticizer (PC) and LS were compared, which revealed that the former has better properties of plasticizing and strength improving. Engineering applications indicated that concrete incorporating the new superplasticizer has advantages on its cohesiveness and pumpability. Moreover, it’s not easy to bleed, segregate and stick to the ground.

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