Heats and Entropies of Polymerization, Ceiling Temperatures, Equilibrium Monomer Concentrations, and Polymerizability of Heterocyclic Compounds

Unexpected differences between thermal and photoinitiated cationic curing of a diglycidyl ether of bisphenol A modified with a multiarm star poly(styrene)-b-poly(ε-caprolactone) polymer

“…This can be clearly appreciated in the inset of Figure 3, where it is observed the same behaviour as at the lower heating rates. Table 1 shows that the reaction heat of all formulations (in kJee -1 ), obtained as the average of the reaction heat at different heating rates, is almost the same and close to the reference value of 100 kJee -1 for epoxy formulations [33]. This suggests that complete curing is reached for all formulations and that the presence of the multi-arm star polymer does not have any effect on the completion of the thermal cure.…”

Epoxy/anhydride thermosets modified with end-capped star polymers with poly(ethyleneimine) cores of different molecular weight and poly(ε–caprolactone) arms

“…Table 3 shows the experimental heats of polymerization, $h, calculated as the average heat of the experiments at different heating rates. On increasing the proportion of modifier $h [J/g] decreases due to the lower content of reactive epoxy and anhydride groups, whereas $h [kJ/ee] remains almost constant and similar to the values reported for other similar epoxy systems [29]. FTIR spectra of both isothermal and non-isothermal cured samples showed that the absorbance bands of oxirane and anhydride groups disappeared completely.…”

Development of materials and technologies for control of polymer recycling

“…2 This is not surprising because the heat of polymerization, an important parameter for estimating the depolymerizability of polymers, has larger negative values for ethylene and propylene, than for styrene (St) and methyl methacrylate, indicating the difficulty in depolymerizing PE and PP. 3 However, cases in which the zip length is controlled by chain-transfer reactions and in which the activation energy value for a depolymerization reaction, such as b-scission, is higher than that of the chain-transfer reactions, the monomer yield can be increased with increase in temperature. In Figure 1, the recovery of monomer and C 2 -C 4 monoolefin fractions from PE [4][5][6][7][8][9] , PP [10][11][12] and polystyrene (PS) [13][14][15][16] are illustrated.…”