Takehisa Matsuda

Polymerization of 2-Oxazolines. I. Cationic Polymerization of 2-Phenyl-2-oxazoline Initiated by Various Oxazolinium Salts of Monomer with Brbnsted Acids

Abstract Various kinds of the complexes of 2-phenyl-2-oxazoline with various Bronsted acids were prepared. From the elementary analysis and spectroscopic analysis of the complex, it was identified to be an equimolar oxazolinium salt. The monomer could be polymerized with the oxazolinium salt to give N-benzoyl-polyethylenimine. The polymer yield in bulk polymerization was linearly proportional to the reaction time, and the number-average degree of polymerization of the polymer obtained at the complete conversion was proportional to the initial molar ratio of the monomer to the complex. The catalytic activities of the oxazolinium salts increased with a decrease in the pKavalue of Bronsted acid in water. The results of the infrared spectroscopy and nuclear magnetic resonance spectroscopy of the oxazolinium salt at room temperature and elevated temperature indicated that the change of the double bond character of the imino and ether linkages is brought about by the complexation. On the basis of these results,...

Solid-State Polymerization of Acrylamide and Methacrylamide by Chlorine under Ultraviolet Irradiation

Abstract Crystalline monomers of acrylamide (AAm) and methacrylamide (MAAm) could be polymerized in the presence of chlorine gas under ultraviolet (uv) irradiation, the shape of the solid crystals remaining unchanged during the polymerization. The yield of polymer increased with increasing amounts of chlorine. It was deduced that chlorine atoms formed by the decomposition of chlorine molecules on the monomer crystals with uv irradiation initiate the polymerization, which proceeds from the surface to the inner part of the crystals. One apparent characteristic of the catalytic solid-state polymerization is that the molecular weight of the polymer increases as polymerization temperature is raised. After the unreacted AAm was sublimated from a partially polymerized crystal, the polymer obtained was found by polarized microscopic investigation to be well oriented and to show sharp Debye-Scherrer rings in X-ray diagram due to crystalline polymer. Polymethacrylamide obtained in the solid-state polymerization by ...

Radical Copolymerization of 2-lsopropenyl-2-oxazoline with Styrene in the Presence of Lewis Acids

Abstract Free-radical copolymerization of 2-isopropenyl-2-oxazoline (IPOZ) with styrene (ST) and methyl meth-acrylate (MMA) was carried out at 60°C. The reactivity of IPOZ (Q=0.81 and e=0.35) was nearly equal to that of MMA. In the radical polymerization of IPOZ in the presence of ZnCl2, the initial polymerization rate and the specific viscosity of the resulting polymer increased with an increase in the concentration of ZnCl2. The tacticities of the polymer determined by the NMR spectrum of the polymer obtained by radical polymerization showed that the content of syndiotactic triads of the polymer obtained in the absence of ZnCl2 was greater than that in the presence of ZnCl2. In the radical copolymerization of IPOZ (Mjand styrene (M2) in the presence of ZnCl2, the apparent reactivity ratio r1 increased with an increase in the ZnCl2 molar content, whereas r2 decreased. The apparent Q and e values of IPOZ increased markedly by the addition of ZnCl2. The radical copolymerizations in the presence of Lewis ac...

Polymerization of 2-Oxazolines. III. Influence of Polymerization Media on the Propagation Reaction in the Cationic Polymerization of 2-Phenyl-2-oxazoline

Abstract The influence of solvent on the cationic polymerization of 2-phenyl-2-oxazoline initiated with 2-phenyl-2-oxazalinium perchlorate was studied in connection with the physical properties of the solvents used. The polymerizations in all solvents used proceeded successively with little termination and transfer reactions. The propagation rate constant in polar solvents was larger than in nonpolar solvents. The propagation rate constant increased with a decrease in nucleophilicity of the solvent used. In binary solvent systems composed of components with similar nucleophilicities and with different dielectric constants, the propagation rate constant increased with an amount of the polar solvent. In binary solvent systems composed of components with similar dielectric constants and with different nucleophilicities, the propagation rate constant decreased with the amount of the solvent having more nucleophilicity. The activation energy (Ea) of the propagation reaction was about 17-27 kcal/mole, and the a...

Polymerization of 2-Oxazolines. II. Kinetics of the Cationic Polymerization of 2-Phenyl-2-oxazoline Initiated by Oxazolinium Perchlorate in N, N-Dimethylacetamide Solution

Abstract The solution polymerization of 2-phenyl-2-oxazoline in N, N-dimethylacetamide media was carried out at 120-150°C with the use of the oxazolinium salt of monomer and perchloric acid as an initiator. A marked acceleration in rate was observed in the early stage of polymerization. After the period of acceleration the polymerization rate and the moles of polymer chains were shown to remain constant, whereas the number-average degree of polymerization increased almost proportionally with an increase in the degree of conversion. The kinetic discussion, divided into two stages, gave the following results: an early stage of polymerization with slow initiation where the moles of the active propagating species increased, and a later stage with a stationary state where the moles of the active propagating species remained constant and the growth of polymer chains proceeded. The kinetics was reformulated as a function of the differential monomer concentration. The simulation of the kinetics with the use of th...

Solid-State Polymerization of N-Vinylcarbazole by Redox Catalyst

Abstract A crystal of N-vinylcarbazole was polymerized by redox catalyst (ammonium persulfite/sodium bisulfate) in a suspended state in water and poly (vinyl carbazole) was obtained. The polymerization proceeded rapidly above 40°C without an induction period in the solid state. The molecular weight of the polymer increased with decreasing catalyst concentration and raising temperature. ηsp/c of polymer was in the range 0.04–0.07 and it was lower than that obtained in radiation-induced solid-state polymerization. Observation of the partially polymerized crystal through a polarizing microscope showed that the polymerization proceeded from the surface of the monomer crystal and that birefringence was observed in the polymer layer. In X-ray diffraction studies it was found that the polymer was crystalline.