Acrylamide based acrylics

This reaction is carried out using a butanol/formaldehyde solution as a single stage in-situ process. Alternatively, it is possible to use an already etherified monomor such as N-isobutoxy methyl aciylamide in the original polymerisation reaction. By this method acrylic polymers with low free formaldehyde levels are produced. 

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Finishes based on acrylamide-based acrylic nitrogen resins... 

Unlike UF and MF resins, acrylamide-based acrylic nitrogen resins need not be blended with another component to obtain flexibility this can be built into the acrylic copolymer by the appropriate choice of monomers (see examples on p. 193). Thus resins with ester linkages in their main polymer chains (e.g. alkyds, polyesters) can be avoided. A cross-linked polymer network can be built up which is resistant to hydrolysis by alkalis in detergents. Coatings can therefore be formulated which are suitable for domestic appliances, being additionally hard but flexible. 

Acrylamide based acrylics are capable of self crosslinking, when subjected to temperatures in excess of ISiy C. Crosslinking is a complex mixture of condensation reactions and side reactions involving the liberation of water, formaldehyde, primary alcohol and ethers. The reaction is catalysed by acids. Bisphenol A epoxy resins are often incorporated into acrylamide acrylic coating formulations to improve performance. This epoxy resin also takes part in the curing reaction. Figure 4-2 lists the major reactions which take place. 

Flexible acrylamide based acrylic resins, crosslinked with 5-10% of an epoxy resin such as Epikote 1001 (Shell Chemicals) are used in sheet fed applications for caps, closures and other deep draw applications such as pudding basins. Acrylamide based resins have a better balance of flexibility and drawing properties combined with process resistance (retortable). 

Hydrolysis of amide groups to carboxylate is a major cause of instability in acrylamide-based polymers, especially at alkaline pH and high temperatures. The performance of oil-recovery polymers may be adversely affected by excessive hydrolysis, which can promote precipitation from sea water solution. This work has studied the effects of the sodium salts of acrylic acid and AMPS, 2-acrylamido-2-methylpropanesulfonic acid, as comonomers, on the rate of hydrolysis of polyacrylamides in alkaline solution at high temperatures. Copolymers were prepared containing from 0-53 mole % of the anionic comonomers, and hydrolyzed in aqueous solution at pH 8.5 at 90°C, 108°C and 120°C. The extent of hydrolysis was measured by a conductometric method, analyzing for the total carboxylate content. 

PEG, 13 736-737 pH-sensitive, 13 743 PHEMA, 13 733-734, 749, 750 poly(acrylamide)-based, 13 737-738 poly(acrylic/methacrylic acid), 13 734 poly(N-vinyl 2-pyrrolidone), 13 739 polyurethane, 13 739 porous, 13 750-751 preparation methods for, 13 731-732 properties and preparation of,... 

Statistical copolymers were reported for N-vinylimidazole and 13b [50], for acrylamide with 9a [11], 9b [12], and 9c [13], and for terpolymers of acrylamide, sodium acrylate, and 9b [51]. Several hydrolytically stable am-monioacetate and pyridiniocarboxylate monomers based on isobutylene with variable length of hydrophobic side chains did not homopolymerize, but these monomers with surfactant properties are suited for copolymerization with electron-poor monomers [52]. 

Although water is known as a natural plasticizer for many polar polymers such as nylon, polyester resins, and cellulosic polymers, similar behavior for polyacrylamide and poly(acrylamide-co-acrylic acid) has not been investigated. In this study, the effect of water content (and/or thermal history) on the Tg s of acrylamide-based pol3 TOers was studied by Differential Scanning Calorimetry (DSC), Thermogravimetry (TG), Thermomechanical Analysis (TMA), and Simultaneous Thermogravimetry - Mass Spectrometry (TG/MS). 

The acrylamide-based polymers used in the study were obtained commercially in powder form. The homopolymers designated as PS-2806, SPP-34 and ALD-18127-7 were supplied by Polysciences, Scientific Polymer Products and Aldrich respectively. Supplied also by Polysciences were our two poly(acrylamide-co-acrylic acid) samples of high and low carboxyl content, PS-2220 and PS-4652. Table I illustrates the molecular weight distribution of these samples as determined by aqueous GPC/Laser light scattering. The acrylic acid contents of PS-2220 and PS-4652 copolymers measured by 90 MHz C NMR were approximately 63% and 15% respectively. Both the GPC and the NMR analyses indicated PS-2220 contained appreciable amounts of impurities. 

Although the free-radical polymerization of MMA typically exhibits a syndiotactic bias (rr triad content = 60%-70%), it has long been known that the stereochemical interactions between the chain-end radical and vinyl monomers in free-radical polymerization can be modified by using chiral protecting groups. For example, the 80 °C AIBN-initiated polymerization (AIBN = 2,2 -azobisisobutyronitrile) of oxazolidine acrylamides based on valine and t rt-leucine ultimately yields highly isotactic (92% m dyad content) poly(acrylic acid) and PMA after chemical modification (Scheme 23.23). " ... 

Although acrylamide-based polymers are rather hydrophilic, they are soft and often swell excessively in water. Therefore, these stationary phases are currently not well suited for HPLC. In addition, the high solubility of acrylamides in water makes them less practical for polymerization in aqueous suspensions. In contrast, acrylates and methacrylates containing hydroxyl groups in lateral chains can be used for the preparation of beads by means of typical suspension polymerization. This is why the majority of commercially available rigid hydrdophlic beads suitable for HPLC are manufactured from these monomers. Some of these typical chemistries were already shown in Fig. 2. 

Thus, a thin strip of gel based on poly(acrylamide-co-acryl-amido-2-methylpropanesulfonic acid) is hanged from a plastic road... 

A polymeric monolith is a continuous porous polymeric rod made from a mixture of an initiator, monomers (including a cross-linking monomer), and a porogen (pore-forming solvent) that are polymerized in situ in a column. Tuning of the porous properties is typically achieved with a mixture of solvents such as toluene, THF, or decanol. The rationale for choosing an initiator depends on the mode of initiation and on solubility aspects. A common initiator is 2,2-azo-bis-isobutyronitrile (AIBN). Most polymerizations are radical polymerizations, activating radical formation either thermally [54] or with UV radiation [55]. Common monomers used in the preparation of polymer monoliths are styrene, (meth)acrylate, and acrylamide-based materials. The formation of the monolith... 

A/ -Vinylformamide (NVF), a reactive functional monomer with novel physical and chemical properties and favorable toxicology (1,2) has shown significant promise in a number of application areas. It is highly reactive under free radical or cationic reaction conditions. The free radically prepared homopolymer is readily water soluble and can be hydrolyzed in a controllable fashion to give cationic or free base amine functional polymers. NVF, like other vinylamides, also copolymerizes well with most commercially available monomers, especially vinyl acetate, acrylamides, and acrylates (2). NVF s moderate toxicity enables the material to be used in applications where there is some possibility of worker exposure. However, it is difficult to obtain with NVF alone the broad range of physical and chemical properties needed for many applications requiring different glass transition temperatures and variable hydrophilic and hydrophobic characteristics. Also, there are situations where the toxicity profile of the monomer system is a primary concern and NVF may not be considered adequately safe. 

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