Date of Award
Doctor of Philosophy (PhD)
The degradation of poly oxy-1,4-phenylene(1-methylethylidene)-1,4-phenylene-oxy-1,4-phenylenesulfonyl-1,4-phenylene (poly(arylether sulfone)), 1, promoted by excess sodium methoxide was evaluated spectrophotometrically. Direct nitration of 1 with ammonium nitrate in trifluoroacetic anhydride produced poly(2-nitroarylether sulfone). The model segment 1 produced by reaction of 2,2'-bis(4-hydroxyphenyl)propane (bixphenol-A) with 7, was nitrated to obtain model segment of 2,2'-bis 3-nitro-4-(4-phenylsulfonyl phenoxy)-phenyl propane. The rate of polymer degradation was estimated by observing the increase in the concentration of phenolate end groups in the presence of sodium methoxide. It was shown that less than 6% degradation of the most reactive polymer, poly(2-nitroarylether sulfone) occurred after one week at 25(DEGREES)C. Comparison of the spectrophotometric measurements with viscosity changes indicated that degradation occurred by random cleavage of the chain segments. Poly oxy-1,4-phenylene-(1-methylethylidene)-1,4-phenylene-oxy-(2-cyano-1,3-phenylene was prepared from bisphenol-A and 2,6-dichlorobenzonitrile. Direct reduction with lithium aluminum hydride yielded the desired poly oxy-1,4-phenylene-(1-methylethylidene)-1,4-phenylene-oxy-(2-aminomethyl)-1,3-phenylene , 45, (eta) = 0.30 dl/g. The primary amine functionality of 45 exhibited the nucleophilic properties expected. Quantitative alkylation with methyl iodide was effected at room temperature in methanol; and anhydrous potassium bicarbonate was employed as the acid acceptor. The poly(quaternary-ammonium salt), exhibited an intrinsic viscosity of 0.7 dl/g in methanol. Treatment of 45 with carbon disulfide in sodium hydroxide yielded a poly(sodium dithiocarbamate salt), with an extent of substitution = 0.66. Reaction of isocyanatoethyl methacrylate (IEM) proceeded readily at room temperature to form a substituted urea adduct, which retains 100% of the methacryl groups. Graft copolymerization with the residual methacryl groups in the adduct and methyl methacrylate was effected by means of phase-transfer promoted free radical reactions, i.e. potassium peroxydisulfate in the presence of 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6). (Abstract shortened with permission of author.).
Rungaroonthaikul, Cholticha, "Modification of Condensation Polymers." (1986). LSU Historical Dissertations and Theses. 4259.