Acrylic based dispersants

The most effective and widely used dispersants are low molecular weight anionic polymers. Dispersion technology has advanced to the point at which polymers are designed for specific classes of foulants or for a broad spectmm of materials. Acrylate-based polymers are widely used as dispersants. They have advanced from simple homopolymers of acryflc acid to more advanced copolymers and terpolymers. The performance characteristics of the acrylate polymers are a function of their molecular weight and stmcture, along with the types of monomeric units incorporated into the polymer backbone. 

Emulsion-based primer plus alkyd finish These are based on acrylic resin dispersions and have the advantage of a rapid rate of drying. They generally have excellent adhesion and flexibility but lack the sealing properties of aluminum primers. 

De Simone et al. synthesized poly(fluoroalkyl acrylate)-based block copolymers for use as lipophilic/C02-philic surfactants for carbon dioxide applications [181]. The particle diameter and distribution of sizes during dispersion polymerization in supercritical carbon dioxide were shown to be dependent on the nature of the stabilizing block copolymer [182]. 

The way to maximise the solids content of the slurry while keeping a reasonable viscosity is through the use of a dispersant. The dispersant helps maintain fine solid particles in a state of suspension, thus minimising their agglomeration or settling. The dispersant is generally a low molecular weight acrylic based polymer. For most applications, cost of dispersant is critical. 

This article studies some of the polymer characteristics influencing the slurry dispersion and describes a new class of acrylic based polymer showing promising dispersing properties for ultra fine calcium carbonate slurries. 

The new route (process C) for manufacturing acrylic based polymers seems very promising. Polymers prepared by this way attain the efficiency of the best dispersants on the market. In the future, we will explore this route, improving parameters which are known to influence dispersant efficiency such as molecular... 

Self-adhesive labels can be applied to most materials wood, plastic, metal, glass, paper and board. As the adhesives are resin-based (plasticised thermoplastics), migration problems can occur when they are applied to certain plastics (PVC, LDPE, etc.). Adhesive systems for pressure sensitive labels include latex and acrylic bases and adhesives which may be applied as a hot melt, or via a solvent, emulsion or dispersion base. Water-based adhesives are currently increasing in use. 

Modem adhesives for self-adhesive labels include acrylic, polyethylene combinations. There is a distinct move away from solvent-based adhesives (for ecological reasons) to water-based dispersion/emulsion systems. 

Imperon Binder. [Hoechst AG] Selfcrosslinking acrylate-based copolymer dispersion for pigment dyeing. 

Heating oil storage premises must be equipped with a collection trap so that any heating oil leaking from the tank cannot contaminate the soil. The interior of these premises must be painted with an officially approved coating material that is not dissolved or penetrated by heating oil. The coating must also cover cracks in the substrate. Multilayer systems based on waterborne acrylic resin dispersions are suitable for this purpose. 

Cross-linkable monomers may be included to make the formulated adhesive curable by catalysis, heat, or radiation, thereby improving the performance of the film, especially at higher temperatures. Since the dispersion has both toughness and tack built in, no further compounding is necessary, making pressure-sensitive acrylic dispersions the easiest products to work with. In most applications, however, the formulator will prefer to modify the properties to order, and use of tackifying resins added either in solution or as a dispersion is common. Vinyl ethers can again be used either as sole binders or as tackifiers to modify the properties of the base dispersion. 

Chem. Descrip. Proprietary acrylate-based, ammonium/sodium salt Uses Dispersant for water-bas coatings, slurries, adhesives, etc. Features Best for dispersibility and gloss Properties Pale yel. dear llq., ammoniacal odor sp.gr. 1.18 g/ml pH 9.5-10.5 anionic... 

Chem. Descrip. Acrylic-based polymer Uses Dispersant for TiOj in water for use in paints/coatings Zephrym PD3315 [UniqemaAm.]... 

Conductive Dispersion 1000 Series Conductive Dispersion 3000 Series conductivity agent, acrylic-based systems ESP conductive coatings Conductive Dispersion 1000 Series Conductive Dispersion 3000 Series conductivity agent, coalings EFKA -6780 EFKA -6782 ElekVoslat 80/ 54 Elekiroslal 100/50 conductivity agent, electrostatic spray... 

Disperse-Ayd 6 defoamer, acrylate-based parquet floor... 

Based on this brief literature survey, it seems quite clear that not all features of the hybrid acrylic-urethane dispersions have been studied so far. The purpose of the present study is to clarify the effect of various factors on the properties of acrylic/styrene-urethane dispersions. Some results of preliminary investigations of the particle morphology will also be revealed. 

Generally, based on the results shown above, it can be concluded that introducing double bonds into polyurethane-urea is undoubtedly one of the ways to obtain coatings of excellent properties based on hybrid polyurethane-urea-acrylic/styrene dispersions. 

A polyanrline-poly(butyl acrylate-vinyl acetate) composite exhibiting electroactivity and having a conductivity of 2.2 S/cm was prepared by emulsion polymerization. The composite was soluble in common organic solvents and a stable water-based dispersion could also be prepared. Films cast from aqueous media had exceptional mechanical properties and had excellent adhesion to steel [144]. From the same group, a polyaniline and polyvinyl alcohol electroactive composite has been synthesized by... 

Solvent-based dispersions such as polyvinyl acetate. Polyurethane, polyesters, polyethers, acrylic copolymers, Rubber-based adhesives with tackifiers and plasticizers. 

Water-based dispersions or emulsions such as polyvinyl acetate, acrylics, polyvinyl chloride and polyvinyl alcohol with plasticizers and tackifiers. In addition, this range can include urea formaldehyde and phenolic adhesives, resins, natural adhesives produced from starch, dextrin, casein, animal glues (see Polyvinyl alcohol in adhesives, Phenolic adhesives single-stage resoles. Phenolic adhesives two-stage novolacs. Animal glues and technical gelatins) and rubber latex (see Emulsion and dispersion adhesives). Solvent-free 100% solids such as polyurethane. Hot melt adhesives include Ethylene-vinyl acetate copolymers, polyolefins, polyamides, polyesters with tackifiers and waxes. More recent additions include cross-linkable systems. 

Tests on acrylic/styrene dispersions having varying minimum film forming temperatures demonstrate that when a suitable binder is used, solvent-free paints can be formulated, which exhibit weathering behaviour comparable to that of conventional solvent-based paints. Rutile titanium dioxide pigments are shown to have a greater influence on weathering resistance than the binder. 6 refs. 

Modifications that contain reactive or polymerizable functionality have been used to improve the clay dispersion in in-situ polymerized styrene-based nanocomposites [2, 5,15, 19, 28, 35, 36, 41, 43-47, 77], and these surfactants are listed in Table 13.2. The notion is that the growing PS chain may polymerize om or througft the reactive group on the surfactant, aiding to push the clay platelets apart and hence improve the prospect of exfoliation. In most cases, the reactive group has been styrene-based although acrylic-based surfactants have also been used (structures 38-41) [46-49]. Figure 13.3 describes the difference between reactive and nonreactive modifications. 

The application of 2-3% omf (on mass of fibre) fixed resin appears to be optimal for easy-care properties, dependant on the fabric constmction and weight. Application levels of 2% omf are needed to stop fibrillation on domestic washing. In addition to the resin, the choice of softener can have a large effect on the easy-care performance of fabrics, and it is important to consider the whole formulation and build it up to give the required performance. Silicone micro-emulsions penetrate yams more than the macro-emulsions. Polyethylene dispersions aid sewing and build the handle of the fabric, whilst some soft acrylic-based chemicals can increase the abrasion resistance. It is also worth remembering that caustic soda or liquid ammonia treatment in preparation will help to increase the easy-care rating of lyocell fabrics. 

T. J. White, L. V. Natarajan, T. J. Bunning, cuid C. A. Guymon, Contribution of monomer functionahty and additives to polymerization kinetics and hquid crystal phase separation in acrylate-based polymer-dispersed hquid crystcils (PDLCs). Liq. Cryst. 34, 1377-1385 (2007). 

The most common preformed rubber particles used as a toughening agent for epoxy polymers are the so-called structured, core-shell latex particles (Figure 4). These particles typically have a polybutadiene-based core and an acrylate-based shell. Such additives can be purchased as powders from Rohm and Haas or Elf-Atochem and can be purchased as epoxy concentrates from the Dow Chemical Company. The key parameter for these modifiers is the composition of the shell polymer, since the shell chemistry plays a crucial role in the overall blend morphology. It should be noted that it is possible to obtain commercial core-shell latex particles with reactive groups in the shell for improved dispersion of the rubber particles. 

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