Poly crosslinking degree

Crosslinked polymer networks formed from multifunctional acrylates are completely insoluble. Consequently, solid-state nuclear magnetic resonance (NMR) spectroscopy becomes an attractive method to determine the degree of crosslinking of such polymers (1-4). Solid-state NMR spectroscopy has been used to study the homopolymerization kinetics of various diacrylates and to distinguish between constrained and unconstrained, or unreacted double bonds in polymers (5,6). Solid-state NMR techniques can also be used to determine the domain sizes of different polymer phases and to determine the presence of microgels within a poly multiacrylate sample (7). The results of solid-state NMR experiments have also been correlated to dynamic mechanical analysis measurements of the glass transition (1,8,9) of various polydiacrylates. 

Recently, a novel hydrophylic polymer membrane based on poly(allylamine hydrochloride) (PAA.HC1)/PVA, crosslinked with GA, has been also tested for methanol dehydration by pervaporation technique [33], Even if the reported results show a small selectivity of the last type of membrane, the blend s composition, the curing degree and the process conditions (temperature, feed concentration, etc.) could be used to obtain a better separation of methanol. 

Kuhn et al. [22] extended their studies to crosslinked networks of poly-(acrylic acid) (PAA) and found that these gels swelled to a high degree in alkaline environment and contracted rapidly when acid was added to the surrounding solution. Dilations and contractions of the order of 300% were observed. They were reversible and could be repeated at will. A contracting and expanding gel... 

Poly(ethyleneimine)(PEI) bridged by alkylene dihalide has been used as a chelating resin for Cu and Co68. Dingman et al,69 studied the adsorption of metal ions on PEI resins crosslinked with toluene diisocyanate. The amount of metal ions adsorbed decreases with the degree of crosslinking. These crosslinked PEI resins... 

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