The radical copolymerization of , '-bisand N,N', N,,-tris(2-hydroxy-3-allyloxypropyl) isocyanurates (DHAIC and THAIC) with methyl methacrylate (MMA) and styrene (S) was studied and the rate constants were evaluated. Increase in the functionality of allylisocyanuric monomers was accompanied by growth of the rate constants for S and MMA. MMA copolymerizes with DHAIC and THAIC at a substantially higher rate than with S. The maximum completeness of copolymerization of S decreased at higher concentrations of THAIC in the initial mixture, while that of MMA passed through a maximum.
SynopsisThe thermal decomposition of cured cyanurophenol-formaldehyde oligorners (CPFR) wm studied by derivatography, IR spectra and EPR spectra. During the heating of CPFR, processes of restructuring and decomposition take place. Up to 330°C the weight losses of CPFR are smaller compared to those of phenol-formaldehyde oligomers (PFR), while above 330°C the opposite is true. Under these conditions the isocyanuric ring is destroyed. The carbonyl absorption sharply decreases at 4OO0C, and a t 500°C there is practically no absorption. This reduction is probably a result of rearrangement of the isocyanuric rings to a secondary polymer in which nitrogen is combined in the form of cyanic links. The energy of decomposition as determined from the thermogravimetric curve is 17 to 24 kcal/mole. On the basis of the EPR sepctra and the low activation energy of destruction, we propose that radical processes play an important part during the process of curing and thermal decomposition of CPFR.
SynopsisCuring and destruction of crosslinked phenolformaldehyde polymers modified with a varying quantity of polycaprolactam were studied by means of IR and ESR spectra and by derivatography. In the curing process of the polymers, hexamethylenetetramine was found degrading, with formation of dimethyleneimine, and other groups causing spatial crosslinking of the polymers.Incorporation of nitrogen in the polymer chains was proved by means of IR spectra and elemental analysis. The activation energy of destruction was determined by the thermogravimetric curves, and it varied in the range of 25 to 32 kcal/mol.
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