How do you make polycarboxylate?
The preparation method comprises the following steps: adding unsaturated polyether methyl allyl polyoxyethylene ether, hydrogen peroxide and 2-acrylamide tetradecyl sulfonic acid into deionized water to prepare a base solution; dripping a solution A consisting of acrylic acid, methacrylic acid and a chain transfer …
What is a polycarboxylate admixture?
Polycarboxylate-based water reducing admixtures (PCE) are widely used in concrete technology as they have superior properties such as ease of molecular structure change, high dispersing and water reduction capacity. Besides these positive effects, PCEs show a high sensitivity to clay particles.
How is superplasticizer made?
They are prepared by crosslinking of the sulfonated monomers using formaldehyde or by sulfonating the corresponding crosslinked polymer.
Is polycarboxylate toxic?
Polycarboxylates are toxic to warm blooded animals only in very high doses. They have virtually no irritant effect on skin and mucous membranes and no sensitizing properties. There has been no indication of possible irreversible genetic damage.
What is the disadvantage of superplasticizer?
The main disadvantage of superplasticizer usage is loss of workability as a result of rapid slump loss and incompatibility of cement and superplasticizers. Superplasticizers are soluble macromolecules, which are hundreds of times larger than water molecule (Gani, 1997).
What is the limitation of plasticizers?
What is the limitation of plasticizers? Explanation: A good plasticizer is one which does not cause air-entrainment in concrete is greater than 1-2%.
What are plasticizers made?
What are they made of? Plasticizers are produced by a reaction of an alcohol with an acid such as adipic acid, phthalic anhydride, and so forth. The choice of alcohol and acid will determine the type of ester that can be produced and hence the kind of plasticizer.
What is sodium polycarboxylate?
Sodium polycarboxylates are anionic polymers with a carbon-carbon backbone and attached carboxyl functionality. Polycarboxylates are identified by the monomers used in their preparation and the molecular weights of the resultant polymers.
What are the uses of polycarboxylate cement?
They are used as filling materials, protective cavity liners, luting materials for crowns, bridges, inlays and orthodontic appliances, root canal fillings, and pulp capping. Various types of cements are available for different purposes.
How should polycarboxylate cement appear?
How should polycarboxylate cement appear after the mixing process? It should have a syrup-like in consistency, which thickens as it sets.