Acrylamide/DADMAC copolymers

C-NMR spectroscopy has also been used to investigate the composition of DADMAC copolymers [38, 45-47]. Copolymers with acrylamide (AAM) have been extensively studied. Based on the chemical shifts in the 13C-NMR spectra of the homopolymers of DADMAC [17-19] and AAM [48-50], the copolymer spectra can be analyzed. Specifically from two likely chad structures (m/r) in PAAM and six different diad structures (r/m, c/t) in PDADMAC, eight different diad structures can be expected for the copolymers. A detailed NMR analysis has therefore been carried out in order to determine the copolymer compositions. The reactivity ratios obtained were found to be in good agreement with the results from other methods, such as potentiometric titration or elementary analysis, provided that the DADMAC in the copolymer was below approximately 70% [38]. 

Copolymers from the monomers AMPS, diallyldimethylammonium chloride (DADMAC), N-vinyl-N-methylacetamide (VIMA), acrylamides, and acrylates are particularly useful for fluid loss additives [824]. The molecular weights of the copolymers range from 200,000 to 1,000,000 Dalton. The copolymers are used in suspensions of solids in aqueous systems, including saline, as water binders. In these systems, the water release to a formation is substantially reduced by the addition of one or more of these copolymers. 

Polymers of N, N, N, A-diallyldimethylammonium chloride (DADMAC) (and its copolymers with acrylamide) are allyl resins in terms of the monomers used but are very different in properties since they are not crosslinked. Cyclopolymerization is the mode of reaction (Sec. 6-6b) and the polymers are water-soluble. Applications include potable and wastewater treatment (flocculation aid) and paper and textile industries (antistatic coating, reinforcement, color removal). 

Fig. 12. Copolymerization DADMAC/acrylamide in aqueous solution. Influence of the initial monomer concentration on the copolymer composition (— data taken from [64] data taken from [65])...

Homopolymers of DADMAC and copolymers of acrylamide and DADMAC are applied in the coagulation of fibers recycled from coated broke, a term used to describe a paper which cannot be sold for different reasons [ 176]. It is claimed that polymer solutions and water-in-oil emulsions containing DADMAC offer both superior performance and cost effectiveness compared to the traditional polymer additives used for this purpose [190,194]. 

Fig. 2 Response of various PECs (first polyelectrolytes in initial solutions) to subsequent addition of salt a particle mass Mw b particle radius am (corrected for polydispersity, obeying the relation Mw=(4/r/3) p am3), c structure density p 1( ) - NaPSS/PDADMAC, X=0.3, 2(0) - NaPSS/PDADMAC, X=0.6, 3(B) - DADMAC-acrylamide copolymer (47 mol% DADMAC)/NaPMA X=0.6, 4(V) - DHP2 (block copolymer of poly(2-acry-lamido-2-methyl-1-propanesulfonic acid) and poly(ethylene glycol), PEG block length 10 kda)/PDADMAC, X=0.6,1-4 addition of NaCl, 5(A) - DADMAC-acrylamide copolymer (47 mol% DADMAC)/Na-PMA, X=0.6, addition of CaCl2...

NaPMA, Mw = 114,000 g/mol). Polycations poly(diallyldimethylammo-nium chloride) (PDADMAC, Mw = 250,000 g/mol) and its copolymers (DADMAC-AA-xr, where xx corresponds to the mol% of DADMAC) with acrylamide of various compositions. Additionally, some findings will be given about PECs between ionically modified pol y(/V-is< >pr< tpylacrylamide) (PNIPAM). 

DADMAC/Acrylamide Copolymer (75/25 Wt %)-Emulsion Polymerization. The following were added to the reaction vessel 64.4 parts benzene, 15 parts DADMAC, 5 parts acrylamide, 13.5 parts deionized H20, and 2 parts sodium octyl phenoxyethoxy-2-ethanol sulfate. The vessel was purged for 1 hr with N2 at 50° 1°C after which 5 ppm Fe+2 and 2 X 10"3 mol f-butylperoxypivalate/mol monomer were added. The temperature was held at 50° 1°C for 20 hr. The product, isolated via acetone precipitation, was found to be a DADMAC/acrylamide copolymer (60/40 wt %). 

DADMAC/Acrylamide Copolymer (75/25 Wt %)-Solution Polymerization. This product was synthesized in a manner similar to the solution homopolymerizations of DADMAC and AMBTAC. The product, isolated via acetone precipitation, was found to contain 60% DADMAC and 40% acrylamide. 

The effect of branching on the performance of 75% DADMAC/25% acrylamide copolymers in dewatering 100% waste-activated sludge was also investigated. A series of copolymers was prepared by an inverse emulsion method adding up to 0.5 mol % TAMAC (based on DADMAC... 

Most water and waste water treatment applications use polymers that are cationic in character that are predominantly prepared by copolymerisation of acrylamide with varying proportions of amino derivatives of acrylic acid or methacrylic acid esters. The most commonly used monomers in this class are dimethyl amino ethyl (meth) acrylate quater-nised with methyl chloride or other quaternising agents. Polymerisation is conducted under acidic conditions to prevent base catalysed hydrolysis of the ester linkage. Copolymers with allyl monomers, such as DADMAC are also manufactured however the molecular weight of these polymers is limited by the relative stability of the intermediate radical. 

Polyacrylamides of high commercial interest are copolymers of acrylamide, 1, with sodium or ammonium salts of acrylic acid, 4, or 2-acrylamido tert-butylsulfonic acid (ATBS), 5, to produce anionic polymers or with aCTyloyloxyethyltri-methylammonium chloride (AETAC), 6 (Fig. 19.2), to produce cationic polymers. Although not produced in large volume, copolymers of acrylamide and DADMAC, 10, are used to produce cationic polymers for use in papermaking applications (Fig. 19.2). Polyacrylamides with a variety of charge densities... 

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