Of polyacrylate-based

When the water-cement ratio is reduced to give a similar slump to a control mix, the setting time is normally very similar to the control perhaps a small decrease in the case of SMF and SNF [64] and a slight increase in the case of polyacrylate-based materials [57], normally no greater than one hour either way. 

Adhesion and Yield of Polyacrylate-Based Photoresist Lamination in Printed-Circuit Fabrication... 

Gregor, H. P. Frederick, M. (1957). Titration studies of polyacrylic acid and polymethacrylic acids with alkali metals and quaternary ammonium bases. Journal of Polymer Science, 23, 451-65. 

These enhance the appearance of the polymer, but play no role in the chemical, physical or mechanical properties of the base polymer. The main difficulty is that if the finished assembled article is made from different grades of the same polymer or from different polymers, then, particularly with different polymers, the combination must be uniform. For example, bathroom suites are often made from different materials, e.g., ceramics, baths (polyacrylates), trimmings (PVC, PP). The colorants therefore have to undergo different processing conditions and it is essential that in the final products the colour is the same. 

More recently, increasing research attention has focused upon the use of mucoadhe-sive delivery systems in which the biopharmaceutical is formulated with/encapsulated in molecules that interact with the intestinal mucosa membranes. The strategy is obviously to retain the drug at the absorbing surface for a prolonged period. Non-specific (charge-based) interactions can be achieved by the use of polyacrylic acid, whereas more biospecihc interactions are achieved by using selected lectins or bacterial adhesion proteins. Despite intensive efforts, however, the successful delivery of biopharmaceuticals via the oral route remains some way off. 

Figure 2. Molecular structure of a polyacrylate-based amphipol [see ref. 5],...

Bouckaert et al. [42] tested buccal tablets of miconazole based on modified starch-polyacrylic acid mixtures. Although these tablets showed different mucoadhe-sion properties in vitro, no significant differences in the salivary content of miconazole could be observed in human volrmteers. 

The zeta potential of the polyacrylate-based materials is significantly lower than that for SNF or SMF as shown in Fig. 2.7 [35]. In fact for a similar lowering of viscosity, the zeta potential for the polyacrylate products can be half that for SNF or SMF [36]. 

The newer polyacrylate-based materials hold promise as a way of holding the high slump over a longer time period, as shown in Fig. 2.18 for one product of this type [62], where it can be seen that the extreme workability is maintained for over two hours. It has been suggested that this is due to this type of superplasticizer operating by the steric hinderence mode of action rather than by electrostatic repulsion [63]. 

Thus, to confirm the preceding, combinations of polyacrylates, phosphonates, and PMA-based products have been mainstays of chemical inhibitor formulations for the last 30 years or so. 

Martin, B. D., S. A. Ampofo, R. J. Linhardt, and J. S. Dordick. 1992. Biocatalytic synthesis of sugar-containing polyacrylate-based hydrogeMacromoleculeS5 7081-7085. 

A numerically controlled mill fabricated trenches and through holes at the ends of the trenches in a thin, colorless, polyacrylic acid plate [26], This thin plate was bonded to a more rigid, transparent polycarbonate base plate with U V-curing optical adhesive. The through holes in the plate were connected to holes in the base plate, thereby forming one conduit. The latter holes did not penetrate the base plate, but rather were connected to cross-type arranged borings. Thereby, fluid connections could be attached to the side of the base plate. 

Early antisealants used sodium hexametaphosphate (SHMP) as a threshold agent to inhibit the growth of calcium carbonate and sulfate-based scales.6 Most antisealants on the market today contain sulfonate, phosphate, or carboxylic acid functional groups. Perhaps the most effective antisealants today contain and blend of polyacrylic acid (PAA) and phosphoric acid or polyacrylate and a hydroyethylidene diphosphonate (HEDP).12 The polyacrylate-HEDP blends also claim to have good dispersion qualities toward silts and clays.12 Some new inhibitors include a chelant and disper-ant to keep suspended solids such as iron and manganese oxides in solution. These newer antisealants are generally more effective than SHMP for a variety of potential scales.6... 

A large number of azobenzene-based amorphous and liquid crystalline polymers, particularly polyacrylates and polymethacrylates with chiral azobenzene pendants, have been prepared for the development of data storage and photonic devices [1-3,11-14]. For instance, the introduction of optically active mesogenic azobenzene residues into the side groups of the polymers produces chiral nematic and cholesteric phases, which are regulated by photoisomerization of the azobenzene units [10,14]. In most cases, however, the optical activity and chiroptical... 

Chromatographic method The determination of silicate based upon the adsorption of preconcentrated phosphomolybdic and silicomo-lybdic heteropoly acid (HPA) in the dynamic mode on a microcolumn packed with an Amberlite XAD-8 polyacrylate adsorbent is reported [49]. The method is based on the adsorption of HPAs followed by desorption with acetonitrile and determination by reversed-phase HPLC. Another highly sensitive HPLC method for the simultaneous determination of soluble silicate and phosphate in environmental waters is used in ion-pair liquid... 

Arenes of the type ArX-Y, where X may be O, S, or NR, frequently undergo facile photoinduced homolytic cleavage of the X-Y bond with the Y radical subsequently attacking the aromatic ring. The photo-Fries reaction is the most common process of this type and has been reported within the year for aromatic esters which form part of a ptolymer chain or are pendant groups on a polymer chain. In the former case, the rearrangement of fluorene-based polyacrylates [for example, (292)] was studied. Formation of the o-hydroxybenzophenone moiety in the product (293) was monitored by u.v. and... 

Polyacrylate resins can be produced from EPOP by reacting them with acrylic acids. These resins can be applied on solid surfaces and when they are cured by ultraviolet irradiation, clear and glossy finishes result. The hardness and the tackiness can be increased or reduced by varying the amount and types of crosslinkers and the strength of the irradiation used (125-127). Characteristics of some polyacrylates based on epoxidized palm olein are listed in Table 48. 

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