April
Concrete and cement products
CHI3~A concrete _ and cement products
Issue 2, 2002
April
Development and properties of polycarboxylic acid series high performance water reducer
Li Chongzhi Li Yongde Feng Naiqian
(Tsinghua University Civil Society, Beijing 100084)
According to the structural characteristics of polycarboxylic high-tech water reducer, the activities of R-band, sulfonic acid group and polyoxyethylene chain ester group were studied by orthogonal test.
The effects of solid elements such as the molar ratio of unsaturated monomers and the pocket degree of polyethylene oxide chain on the properties of polycarboxylic acid water reducer were obtained, and the synthesized polyethylene oxide was obtained.
This is the best formula of acid-based high performance alkaline water reducer. The self-inspection of the trial-produced products shows that polycarboxylic acid water reducer has excellent dispersion ability and can emit odor for a long time.
It maintains its rheology, good compatibility with different cements, good cohesiveness of cement paste and good performance of prepared concrete.
Key words: polyacid controlled water reducer; Phenotypic molecular structure
In this paper, the influence of the ratio of unsaturated vinyl groups on M was studied by orthogonal experimental analysis.
... class =' class1' > sulfhydryl groups on the side chain of polyoxyethylene (peo) and the influence of molecular coffee degree ...
The results show that the polyene water reducer has excellent performance.
Mch has good dispersibility and is used to maintain fluidity. It has good compatibility with all kinds of Ⅱ M, and the four ∞ t adhesion is good.
In the past week, there was a good mercury column in that concrete mountain.
Key words: polycarboxylic acid water reducer; synth~is:Molectdar 8mIcnJ
China Library Classification Number: TU5~042 2 Document Identification Number: A Document Number: 1O00-4637 (2002 JD2-03-o4
Preface of 0
With the development of modern concrete technology, the durability of concrete refers to
With the continuous improvement of standards, the water-binder ratio of concrete will become smaller and smaller; In addition, due to
With the development of high-rise buildings and deep underground space, high strength, high efficiency,
The consumption of ultra-high strength fluidity concrete is also increasing, so is the requirement.
The water-binder ratio is less than 0.25, the compressive strength is greater than 100MPa, and it can keep good.
Concrete with good fluidity. The purpose of high-performance water reducer is to obtain high-performance coagulation.
The key material of soil not only has high water reducing effect, but also
It is required to control the slump loss of concrete and solve the setting problem better.
Such as air entrainment, blockage and soil erosion. At present, in many series of restores,
Among the aqueous reagents, polycarboxylic acid alkaline aqueous reagents with comb-like molecular structure
(polyarylether water reducer, referred to as Pc series water reducer.
Agent) has strong dispersibility, low content and small slump loss of concrete, and is made in China.
Research and development hotspot of external chemical additives-ZL
In this paper, excess acrylic acid was partially esterified with polyethylene glycol to obtain acrylate.
Polyethylene glycol monoacrylate (PA) series. Then orthogonal test was used.
In research method L, stilbene group and methyl propyl sulfonate group contained in acrylic acid were analyzed.
Sodium olefin sulfonate, polyethylene glycol monoacrylate based on polyoxyethylene chain, etc.
Molar ratio of unsaturated monomer to polyethylene oxide.
The effects of chain polymerization length and other factors on the properties of synthetic products were found.
The optimum formula of polycarboxylic acid series high performance water reducer is given. Preliminary tests have proved that
Ming, the synthesized product has good dispersibility, no retarding, obvious early strength effect, cement
Slurry fluidity loss is small, and the actual dosage is very low.
The comprehensive performance of series water reducer powder products is far less than that of liquid poly.
Carboxylic acid is a high performance water reducer, among which PC23 synthesized by the author has low performance.
ADVA 105, a water reducer of Japan's w.R.GRACE Company.
This Kao company's 7 Yu 3000S high-performance AE water reducer product.
Its performance is similar and its engineering application prospect is broad.
Molecular structure of 1 polybasic acid series high performance water reducer
Firstly, acrylic acid was partially esterified to obtain PA series with different chain lengths.
Then adopt carboxyl group (COOM) and sulfonic group (SOjM) with active groups,
Unsaturated monomers such as polyoxyethylene chain groups (PEO- 1), etc. According to some
The proportion in water is initiated by polymerization of initiator with comb-like molecular structure.
Polycarboxylic acid water reducer. The following chemical formulas represent * * * monomers and.
Chemical structure of polycarboxylic acid water reducer
R R R 0
Methane 2 = carbon methane 2 = carbon methane 2 = carbon
I will
CH 2 C=0 C=0
Me, me.
SO 3 M O(CH 2CH 20)nR Medal of Merit
MAS or SAS PA0 or p 9 or PA23 or PA35 MAA or KA.
Monomer monomer monomer monomer monomer
R R R
q-ch 2-⊙cn-⊙cn:⊙ 10
C=0 CH 2 C=0
『l l
OM SO M 0(CH CH 20)nR
Molecular structural formula of Pc series water reducer
three
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