2-Hydroxy-4- 2, 3 epoxypropoxy benzophenone

BA BuE-PA BE-HET BE-HHPA BE-MA BE-PA BE-SA CA CHX DMA DMBA DY 062 GA HEB HHPA HMTA MA MTHPA NMA benzoic acid monobutylester of phthalic acid monobenzylester of hexachloroendomethylenetetrahydrophthalic acid monobenzylester of hexahydrophthalic acid monobenzylester of maleic acid monobenzylester of phthalic acid monobenzylester of succinic acid citraconic anhydride cyclohexanol N,N-dimethylaniline dimethylbenzylamine high boiling tertiary amine (Ciba Geigy AG) gjptaric anhydride 2-hydroxy-4-(2,3-epoxypropoxy)benzophenone hexahydrophthalic anhydride hexamethylenetetramine maleic anhydride methyltetrahydrophthalic anhydride nadic methyl anhydride (methylbicyclo[2.2.1]heptene-2,3-dicarboxylic anhydride isomers)... 

Fig. 1. Effect of hexadecyltrimethylammonium bromide (CAB) on the copolymerization of 2-hydroxy-4-(2,3-epoxypropoxy)benzophenone (0.5 mol/1) with phthalic anhydride (0.5 mol/1) in nitrobenzene at 120 °C56)...

Fig. 3. Conductivity curves of the copolymerization of 2-hydroxy-4-(2,3-epoxypropoxy)benzophenone (0.5 mol/1) with phthalic anhydride (0.5 mol/1) in o-xylene at 120 °C initiated by various initiators.57) 1 — tri-n-hexylamine (0.025 mol/1) 2 - tri-n-hexylamine (0.025 mol/1) and cyclohexanol (0.025 mol je 1) 3 — tri-n-hexylamine (0.025 mol/1) and benzoic acid (0.025 mol/1) 4 — hexadecyltrimethyl-ammonium bromide (0.005 mol/1)...

Solvent polarity influences the rate of copolymerization. Thus with increasing dielectric constant of the solvent, the copolymerization rate rises as a result of the increase in the dissociation constants of the active species. The apparent rate constant for the copolymerization of 2-hydroxy-4-(2,3-epoxypropoxy)benzophenone with phthalic anhydride, initiated by hexadecyltrimethylammonium bromide56), increases from 4.65 x 10 4 s 1 in o-xylene to 6.84x 10 4 s-1 in nitrobenzene. Hilt et al.S4) proposed a suitable model illustrating the effect of solvent polarity in the copolymerization of phthalic anhydride with ethylene glycol carbonate in a mixture of nitrobenzene and trichlorobenzene (Table 4). With increasing fraction of the more polar nitrobenzene, the rate of copolymerization increases. 

Equation (31) allows the determination of the ratio of propagation rate constants k3/k2 by correlation of the experimental results obtained in copolymerization using equimolar ratios of monomers with the results obtained at non-equimolar monomer ratio and excess of anhydride (an excess of epoxide should not be used because of homopolymerization of the monomers at high degree of conversion). A value of k3,/k2 equal to 0.2 0.1 was found for the system 2-hydroxy-4-(2,3-epoxypropoxy) benzophenone-phthalic anhydride in nitrobenzene initiated by hexadecyltrimethyl-ammonium bromide 56). 

Second-order kinetics with respect to the amine and epoxide was also found by Antipova et al. 65) for the curing of epoxy resins with hexahydrophthalic anhydride, by Sorokin et al.321 for the reaction of phenylglycidyl ether with phthalic anhydride in the presence of butanol, Luston and Manasek 45 74) for the copolymerization of 2-hydroxy-4-(2,3-epoxypropoxy)benzophenone with phthalic anhydride in the absence or in the presence of proton donors, and Kudyakov et al. 98) for the curing of epoxy resins with maleic anhydride. 

An alternative approach is to incorporate a benzophenone-type stabiliser into the polymer backbone, usually at low levels (0.1-5 wt%). Hoechst AG [32] claimed to achieve this by creating a stabilising moiety in the backbone by reacting ethylene glycol, terephthalic acid and 4-hydroxy-6-t-butylisophthalic acid, but other workers preferred to use a benzophenone stabiliser with a substituent containing two hydroxyl groups, e.g., 2-hydroxy-4(2,3-dihydroxypropoxy)benzophenone, to react with other ingredients in the reaction kettle [39, 40, 43], or 2-hydroxy-4(2,3-epoxypropoxy) benzophenone [31]. 

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