Water based polymer systems

These water-based inks use water-based polymer vehicles. There are three main types of water-based polymer systems 1. latexes ... 

PUs are also widely used as coating materials sold as finished polymers, two-part systems, and prepolymer systems. Water-based PU systems are now available allowing easy home use. Aromatic diisocyanate-derived coatings generally offer poor external light stability while aliphatic-derived systems offer good light stability. 

The benefits demonstrated from the preservative use of Bronopol alone and in combination with other preservatives have been realised in several other application fields, namely polymer dispersions, adhesives, paper coatings and water-based paints. By way of example, the results of a study in a water-based paint system are reported, where Bronopol is evaluated alone and in combination with 2,2-dibromodicyanobutane (DBDCB). 

Water-based solvent systems originally developed for the separation and purification of proteins and other biomaterials (Walter et al., 1985) have been suggested for the treatment of contaminated aqueous waste-streams. Certain pairs of water-soluble polymers are incompatible in solution together, and this can lead to phase separation in which two phases are formed. Both phases are predominantly water, and each contains only one of the two polymers. Similar phase behavior results with some polymers and high concentrations of organic salts. The properties of the two phases ensure that the environment-afforded targeted species is different in the two phases. 

In addition to its use in PTT, 1,3-propanediol can replace traditional glycols in urethane-based polymer systems, improving thermal and hydrolytic stability. As a partial substitute for traditional glycols in polyester systems, 1,3-propanediol can improve coating flexibility without affecting other key properties. Other applications include engine coolants and water-based inks (33). 

Many polymers have a limited life and are subject to aging processes even before they are used in production. To delay these aging processes to a usable time period, antioxidants, antihydrolysis agents, and stabilizers are added to adhesive formulations. Antifungal agents or biocides are used in many water-based adhesive systems. 

The decrease in expansion seems to occur at moisture levels above 30°/o moisture for both cereal (starch-based) polymer systems, and protein (soy grits). This corresponds to a point on their adsorption curves where water activity rises rapidly with added moisture that is, at a level where the water added to a mix has little effect on primary hydration of polymers, but behaves as a diluent. In mechanical terms, this may be explained by proposing that at above levels of 25°/o-30% water plasticisation of the polymers is complete, and further added water acts as a lubricant, reducing the shear-induced temperature rise and particle damage necessary for the formation of homogeneous melts. 

While most of the subjects discussed up to this point involve injection molding or extrusion applications, there are a considerable number of other applications where polymer blend technology is and will be employed including adhesives, sealants, coatings, and thermosetting systems, polymeric membranes, and water-based polymers. 

Since the 1970s polymer dispersions manufactured by emulsion polymerization have increasingly substituted solvent-borne paints, coatings, adhesives and inks. Water-based emulsion systems have made a significant contribution to VOC-reduction in corresponding industries. The emulsifier in... 

Surfactants are added to a thermoset resin system to promote the dispersion of fillers in the resin matrix. Recently, surfactants have been used to disperse carbon nanotubes in polymer matrices [48-50]. Surfactants are of two types neutral and ionic. Surfactants have many applications in coating industries for the development of a water-based resin system [51]. Surfactants are added to phenolic or polyurethane foam formulation in which they facilitate formation of small bubbles. The size and uniformity of bubble formation results in a fine cell structure. A surfactant reduces the surface tension of resin formulations and provides an interface between the highly polar resin and the non-polar blowing agent. The surfactant for a particular resin system must be selected carefully so that it is compatible with the resin and resistant... 

Probably the main step to eliminate VOC in the polymer industry has been the substitution of solvent-based systems by waterborne products. Nowadays, about 5% of the polymers are produced by aqueous dispersion processes, mainly by suspension and emulsion polymerization [8]. The water-based polymers, however, are not totally free of monomer and VOCs, since the reaction does not reach completion and VOCs arising from impurities in the raw materials or from by-side reactions can be present. There are two main ways to reduce the residual monomer content in waterborne polymers post-polymerization or/and devolatilization. 

NeoPac E-850 is a formaldehyde-free, water-based aliphatic polyester urethane-acrylic dispersion. This system was developed specifically for use in wood furniture adhesives due to its bond strength and excellent water and heat resistance. As a water-based polymer, it can be highly loaded with mineral fillers to reduce the overall water content in the formulated adhesive without loss of adhesion properties. This is a necessary requirement for most wood laminating production methods in controlling viscosity, wood penetration and faster drying. 

Floor-covering adhesives made from water-based polymer emulsions contain approximately 10-20 % dry polymer in both European and North American systems. Floor-coverings are bonded using an application rate of about 250-500 g wT. ... 

Various types of amphiphilic water-soluble polymers have been a focus of considerable interest over the past decade from both scientific and practical perspectives. The scientific interests are derived from their molecular selforganization phenomena, which are relevant to biological polymer systems and to their nanoscopic molecular frameworks as a basis of materials science. Practical interests stem from their usefulness in a variety of applications, such as polymeric surfactants, emulsifiers, solubilizers, associative thickeners, rheology modifiers, flocculants, and colloid stabilizers. These applications are particularly important in such industries as paint, coating, printing, paper, ceramic, drug, and cosmetic or personal care goods [1-3]. In addition, these water-based polymers have become more important than ever as environmentally friendly materials. 

Water-Based Muds. About 85% of all drilling fluids are water-based systems. The types depend on the composition of the water phase (pH, ionic content, etc), viscosity builders (clays or polymers), and rheological control agents (deflocculants or dispersants (qv)). 

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