Solvent absorption , acrylated

The kinetics of the laser-induced polymerization was followed either by measuring the thickness of the insoluble polymer film formed on the quartz plate after laser exposure and solvent development, using UV spectroscopy or by monitoring the decrease of the IR absorption of the coating at 810 cm-1 which corresponds to the twisting vibration of the acrylate CH2=CH double bond. This last method permits accurate evaluation of the rate of polymerization (Rp) by observing the variation of the 810 cm-1 band, and using Equation 2 ... 

Acrylic. Acrylic resins (polymethyl methacrylate) have exceptional optical clarity and good weather resistance, strength, electrical properties, and chemical resistance. They have low water absorption characteristics. However, acrylics are attacked by strong solvents, gasoline, acetone, and similar organic fluids. 

To prevent subsequent changes the products formed are quenched and absorbed This operation, which lowers the temperature from 140 to 150°C to between 65 and 70°C, takes place by recirculation at 20 to 30°C of water or an organic solvent with a boiling point higher than that of acrylic add (such as diethylphthalate). This solution tends to simplify the subsequent purification operations, but is not widely used commercially. The operation is supplemented by the recycling of a fraction of the absorption liquid previously cooled, to between 40 to 50°C... 

As would be expected, the solubility in organic solvents increases and the water absorption decreases as the Mcohol chain.in the ester group is lengthened. AH the acrylates and methacrylates give polymers which exhibit the outstanding transparency and aging properties which have made these... 

Acrylics are thermoplastic resins based on acrylates or derivatives such as amides and esters. Acrylics are available as emulsions, solvent solutions, and monomer—polymer mixtures (one or two components) with a catalyst. Emulsion—solvent types set by evaporation and absorption of a solvent. Polymer mixtures set through polymerisation by heat, ultra-violet radiation and/or the action of a chemical catalyst. 

The C-H stretch first overtone of terminal methylene groups of vinyl and vinylidene structures is isolated enough that it can be used in traditional quantitative analysis. Figure 3.1 provides one example, and Table 3.1 provides some typical peak locations. Goddu provides tables of absorp-tivities for the first overtone absorption of the terminal methylene group in a variety of compounds and solvents. Molar absorptivities are about 0.2-0.5 1/mol-cm. Put another way, a 100-ppm amount of methylene gives an absorbance of 0.01 in a 10-cm cell. Analyses using this peak to measure the vinyl content of acrylate monomers, butadienes, and edible oils" have been reported. 

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