Лако-красочные материалы — производство

Along with the physicochemical characteristics of the bioadhesive and mucin-epithelium surface, physiological events in the area in which adhesion occurs must be addressed to optimize the drug delivery system. Most delivery systems utilizing bioadhesives are designed to be topically applied to a targeted tissue. Drug delivery systems using bioad­hesives can be applied to many areas […]

Various techniques have been designed to study the strength of adhesion between biolo­gical substrates and water-soluble or water-insoluble polymers. Adhesive quantitation of water-insoluble polymers usually involves measurement of tensile and shear strength of adhesion. In an appropriate buffer solution, the polymer is sandwiched between either two biological membranes or a membrane and a nonbiological substrate, […]

The physicochemical criteria for potential bioadhesion have been studied extensively for both natural and synthetic polymers. Past studies have shown that polyethylene glycols [16], sodium carboxymethyl cellulose [17], and potassium carrageenan [16] need a mini­mum molecular weight for bioadhesion. Further, the molecular weight of a compound has been shown to be proportional to its bioadhesive […]

A. Bioadhesive Examples The majority of work using bioadhesives in drug delivery has been with a small number of water-soluble and water-insoluble polymers. Water-soluble polymers are not cross-linked, whereas water-insoluble polymers are often swellable networks joined by cross-linking agents. Bioadhesives can be natural or synthetic in origin, but in drug delivery systems, nonbiological macromolecules or […]

Most animal cell membrane surfaces are covered with glycoproteins and glycolipids extending from the cell exterior [13]. Collectively, all the polysaccharide structures on the outer surface of the cell are referred to as the glycocalyx [14]. The glycocalyx is continually being synthesized by the underlying cells [14] and is thought to be partly responsible for […]

All external cavities of the body are lined with a continuous, thick, gel-like structure called mucin. Although the thickness varies depending on the type of tissue [3,4], this layer serves as a protective barrier between the cell surface and its external surroundings. Mucin is secreted by goblet cells and special exocrine glands [5] and can […]

Brian K. Irons[32] Columbia Research Laboratories, Madison, Wisconsin, U. S.A. Joseph R. Robinson University of Wisconsin, Madison, Wisconsin, U. S.A. I. INTRODUCTION The use of bioadhesives in drug delivery systems is by no means new, although increased interest in its unique applications in therapy is evidenced by the recent spate of publica­tions. Bioadhesives complement drug […]

During the hot press cycle the hardening of the resin and possible reactions of the adhesive with the wood substance take place. The influential parameters are especially the press temperature and the moisture content in the mat. Additional parameters are the wood density, porosity, swelling and shrinking behavior of the wood, structure at the surface, […]

The wood moisture content influences several important processes such as wetting, flow of the adhesive, penetration into the wood surface, and hardening of the adhesive in the gluing and production of wood-based panels. In bonding solid wood usually a wood moisture content of 6 to 14% is seen as optimal. Lower wood moisture contents can […]

A. Adhesive Consumption and Glue Spread in the Production of Particleboards Several aspects regarding the proportion of adhesive to be used in the production of particleboards must be evaluated to obtain good results: proportion of adhesive on individual particles proportion of adhesive in particle mixtures and fractions proportion of adhesive in the total particle mix […]