Hydrophilic copolymers polymer

Polysaccharides are hydrophilic natural polymers that can be degraded enzymatically. Block copolymers containing polysaccharide as a block were reviewed recently... 

Interpolyelectrolyte complexation between various charged (co)polymers or between charged double-hydrophilic copolymers and surfactants has been used as a tool to generate well-defined micellar structures, as will be discussed in more detail in Sect. 7.4. 

Balazs and Lewandowski (1990) have performed simulations of the adsorption of triblock copolymers onto a planar surface, and examined the conformations of the adsorbed chains. Monte Carlo simulations were performed of the motion of hydrophilic-hydrophobic chains on a cubic lattice. These simulations revealed a complex structure in the interfacial region due to the self-assembly of chains, driven by the solvent-incompatible block, reducing adsorption onto the surface. The influence on the surface coverage of length of the hydrophilic segement, polymer concentration, interaction energy between hydrophilic block and the... 

In the mid to late 1990s, Mimotopes was producing rigid injection molded polypropylene devices that were surface grafted with either a hydrophilic copolymer of methacrylic acid/dimethyl acrylamide or the relatively hydrophobic polystyrene.12 The polymer was then suitably deriva-tized to allow the incorporation of a linker system. In contrast to the various commercial resins available at the time, the Crown was a macroscopic, quantized solid phase. As shown in Fig. 2, the Crowns were typically fitted to a polypropylene stem, which in turn could be fitted into a... 

Homopolymers of methacryloyloxyethyl-type monomers containing 5-FU, thymine, or adenine were very stable toward acids and bases, while their hydrophilic copolymers were found to be degraded in aqueous solution under mild conditions to give the derivatives of purine and pyrimidines. The derivatives released from the copolymers were identified by UV spectroscopy as N-hy-droxyethyl derivatives of 5-FU, thymine, or adenine after isolation by preparative TLC. This means that the ester groups of the polymer side chains were hydrolyzed in aqueous solution. 

Nanogels Cross-linked hydrophilic copolymers, e.g., Pluronic-poly(ethylenimine) (PEI) and polyethylene oxide (PEO)-PEI Covalent conjugation of polymers 20,51,52... 

Soft lenses are made of hydrophilic hydrogel polymers that contain 36-74% water. Other plastics and copolymers are added to alter the physical characteristics of the lens. The diameter is 10.5-15.5 mm and the thickness at the center 0.03-20 mm. Soft lenses can correct most optical defects, including myopia, hyperopia, and astigmatism. Bifocal lenses are also available. They can be colored with either transparent hnes or opaque patterns to change apparent eye color or to mask malformations of the cornea or iris. They are available for daily, weekly, and twice-weekly disposable nse, 1-3 months frequent replacement, and annual replacement. 

Acrylic acid can be used as comonomer in different copolymers. The most common of these are probably poly(ethylene-co-acrylic acid) (see Section 6.1, Figure 6.1.7), poly(acrylic acid-co-acrylamide), and poly(acrylic acid-co-styrene-co-acrylonitrile) or ASA terpolymer. The acrylic acid in the poly(ethylene-co-acrylic acid) increases the wettability of the polymer. Different salts of poly(acrylic acid-co-acrylamide) are used in the water purification processes as water clarification aid and in drilling fluids. Additional -COOH groups make the polymer even more hydrophilic, and polymers such as poly(acrylic acid-co-maleic acid) are easily water soluble and used as liquid thickeners. 

The release profiles were also fitted to Eq. (1) using a nonlinear regression program to obtain estimates of B, the erosion rate. R 2 in all cases was greater than 0.99 and hence the good fit of the release profile to Eq. (1). The optimized values of B obtained by nonlinear regression are listed in Table 18. The erosion rate ranged from 0.0037 cm/day for the most hydrophobic copolymer. P(FAD-SA) 80 20 to 0.028 cm/day for the most hydrophilic copolymer, P(FAD-SA) 10 90. However, the erosion rate was not linearly dependent on the hydrophili-city of the polymer, expressed as % of sebacic acid in the copolymer (Fig. 18). 

Lens hazing and protein deposition are common problems for wearers of soft contact lenses. Previous experiments with hydrophobic-hydrophilic copolymers exposed to plasma showed protein adsorption to be minimal at intermediate copolymer compositions. Adsorption of proteins from artificial tear solutions to a series of polymers and copolymers ranging in composition from 100% poly (methyl methacrylate) (PMMA) to 100% poly(2-hydroxyethyl methacrylate) (PH EM A) was measured. The total protein adsorption due to the three major proteins in tear fluid (lysozyme, albumin, and immunoglobulins) was at a minimum value at copolymer compositions containing 50% or less PH EM A. The elution of the adsorbed proteins from these polymers and copolymers with various solutions also was investigated to assess the binding mechanism. 

The accumulation of proteins on contact lenses has long been viewed as an undesirable event. In this study, the effect of polymer composition on both the total amount of protein on the materials, and on the specific proteins on each polymer composition was documented. The importance of these factors for biological response is not known, so this situation remains a fertile area for investigation. This study also demonstrated that a linear variation in material composition will not necessarily result in a linear variation in absorbed layer protein composition. The minima and maxima noted at intermediate copolymer compositions have strong implications for both understanding the mechanism of protein adsorption and for biological response. Investigation is underway to explore further protein interaction with hydrophobic-hydrophilic copolymer materials. 

Polystyrene resin, frequently used resin material for solid-phase peptide synthesis (SPPS). The polymeric support for SPPS must be chemically inert, mechanically stable, completely insoluble in the solvents used, and easily separated by filtration. For many applications a copolymer of polystyrene with 1% of divinyl benzene as crosslinker is used. The dry resin beads are able to swell up to the five-or sixfold volume in the different organic solvents mainly used for peptide synthesis (e.g., dichloromethane or dimethylfor-mamide). For SPPS the resin material must be chemically functionalized in order to allow for attachment of a handle/liker (e.g. Wang resin), or the first amino acid (—> Merrifield resin). Hydrophilic tentacle polymers gels (TentaGel) are obtained by grafting polyethylene glycol (PEG) chains with an arbitrary degree of polymerization onto porous polystyrene beads. 

Many synthetic hydrophilic vinyl polymers and copolymers have been studied as water-soluble drug carriers, most of them being based on substituted acid derivatives or on vinyl monomers (e.g., N-vinylpyrrolidone). In principle, these polymers contain... 

Furlong, S. A., and Armes, S. P. (2000). Facile synthesis of hydrophilic-hydrophilic copolymers via atom transfer radical pol5merization. Polym. Prepr. (Am. Chem. Soc., Div. Polym. Chem.), 41(1) 450-451. 

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