Hydroxyethyl methacrylate copolymer composition

Table A. Composition of Styrene—Hydroxyethyl Methacrylate Copolymers Determined by Chemical Analysis...

Structural studies of polymer surfaces. Materials that have been studied include PMMA [239], PMMA-polypyrrole composites [240], polyfchloromethyl styrene) honnd 1,4,8,11-tetrazacyclotetradecane, polyfchloromethyl styrene) honnd thenoyl triflnoroacetone [241], poly(dimethyl siloxane)-polyamide copolymers [242], PS [243], ion-implanted PE [244], monoazido-terminated polyethylene oxide [245], polynrethanes [246], polyaniline [247], flnorinated polymer films [248], poly(o-tolnidine) [249], polyetherimide and poly benzimidazole [250], polyfnllerene palladinm [251], imidazole-containing imidazolylethyl maleamic acid-octadecyl vinyl ether copolymer [252], polyphenylene vinylene ether [253], thiophene oligomers [254], flnorinated styrene-isoprene derivative of a methyl methacrylate-hydroxyethyl methacrylate copolymer [255], polythiophene [256], dibromoalkane-hexaflnorisopropylidene diphenol and bisphenol A [257], and geopolymers [258]. 

To study the internal crosslinking of styrene-hydroxy ethyl methacrylate copolymers, it was necessary to prepare a range of well characterized materials containing only low concentrations of hydroxyethyl methacrylate. To ensure that the copolymers were of uniform composition, only low monomer conversions were used so that the composition of the monomer mixtures did not change appreciably during the reaction. Low polymerization temperatures were used to obtain high molecular weight copolymers. 

Polymers are used frequently in paints and varnishes. These materials are usually filled with opaque materials and are difficult to separate or analyze by other procedures. Pyrolysis can be used to identify the nature of the paint, to measure quantitatively residual monomers, for quality control, and to examine additives [5, 13, 14]. Paints may contain a variety of polymers and copolymers such as vinyl derivatives, polyurethanes, phthalate polyesters, etc. Varnishes may contain various copolymers, siloxanes, etc. and can have a complex composition. This composition can be successfully analyzed using analytical pyrolysis. For example, the composition of a coating material consisting of the terpolymer poly(2-hydroxyethyl methacrylate-co-butyl acrylate-co-ethyl methacrylate) crosslinked with butoxy melamine resin has been analyzed with excellent results based on various monomer ratios resulting from pyrolysis at 590° C [15]. 

A membrane-controlled drug delivery device was developed to release tetracycline at zero-order rates. The tetracycline delivery vehicle Is a trllamlnate disk consisting of core and coating membranes fabricated from a series of 2-hydroxyethyl-methacrylate and methylmethacrylate copolymers. Appropriate adjustment of the monomer composition ratio Imparts a hydrophobic nature to the copolymer outer coating membrane (relative to the... 

Many approaches have been developed for the production of ionic liquid-polymer composite membranes. For example, Doyle et al. [165] prepared RTILs/PFSA composite membranes by swelling the Nafion with ionic liquids. When 1-butyl, 3-methyl imidazolium trifluoromethane sulfonate was used as the ionic liquid, the ionic conductivity ofthe composite membrane exceeded 0.1 S cm at 180 °C. A comparison between the ionic liquid-swollen membrane and the liquid itself indicated substantial proton mobility in these composites. Fuller et al. [166] prepared ionic liquid-polymer gel electrolytes by blending hydrophilic RTILs into a poly(vinylidene fiuoridej-hexafluoropropylene copolymer [PVdF(HFP)] matrix. The gel electrolytes prepared with an ionic liquid PVdF(HFP) mass ratio of 2 1 exhibited ionic conductivities >10 Scm at room temperature, and >10 Scm at 100 °C. When Noda and Watanabe [167] investigated the in situ polymerization of vinyl monomers in the RTILs, they produced suitable vinyl monomers that provided transparent, mechanically strong and highly conductive polymer electrolyte films. As an example, a 2-hydroxyethyl methacrylate network polymer in which BPBF4 was dissolved exhibited an ionic conductivity of 10 S cm at 30 °C. 

Dispersancy Solution copolymers are comparatively easy to produce in dispersant form as copolymerization with an appropriate polar monomer is relatively straightforward. If the polar monomer is also a methacrylate, reactivity ratios are essentially the same and no special procedures are required to produce random copolymers. Commercial examples have included dimethyl (or diethyl)aminoethyl methacrylate [11], hydroxyethyl methacrylate [12] and dimethylamino-ethyl methacrylamide [13]. 2-Methyl-5-vinyl pyridine [14] has also been used commercially, reactivity ratios are such that it copolymerizes slightly faster than alkyl methacrylates. Although composition drift is not severe, it should be added in a programmed fashion if a uniform distribution is desired. V-vinyl pyrrolidinone, in contrast, copolymerizes very sluggishly with methacrylates and is best incorporated via a graft reaction [15], sometimes also grafted in combination with V-vinyl imidazole [16]. Since solution chemistry is used to produce dispersant polymethacrylates, like preparation of the base polymer, only relatively simple process modifications are necessary to produce dispersants commercially. 

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. 

Copolymers of 2-hydroxyethyl methacrylate (HEMA) and l-vinyl-2-pyr-rolidone (VP) in the form of cylindrical hydrogels (8 mm x 20 mm) have been prepared radiochemically and the sorption of water into these cylinders has been studied by the mass-uptake methods and by magnetic-resonance imaging at 310 K. The equilibrium water contents for the cylinders were found to vary systematically with the copolymer composition. NMR-imaging studies showed that, while the profiles of the water diffusion fronts for cylinders with high HEMA contents were Fickian, those for the 1 1 copolymer was not and indicated that the mechanism was Case III. The polymers which were rich in VP were characterized by a water-sorption process which follows Case-III behavior. 

IPNs and gradient IPNs based on polyether-urethane-urea (PEUU) block copolymers and acrylamide, 2-hydroxyethyl methacrylate (HEMA), or N-vinyl-2-pyrrolidone. Intended for biomedical uses, such compositions created high-strength, water-absorbing hydrogel surfaces showing good blood compatibility. 

By a similar polymerization technique, copolymers of A-vinylpyrrolidone and 2-hydroxyethyl methacrylate, some with—others without—ethylene dimethacrylate were prepared. The effect of composition and concentration of cross-linking agent on swelling in water was studied. In the case of terpolymers high in N-vinylpyrrolidone, inhomogeneous cross-linking was noted [87]. 

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