Photogeneration of polyfunctional amines and novel thermal curing reactions of epoxy resin and polyurethane oligomer using these amines

Photochemical reactions of various blocked polyfunctional amines such as bis(4-formylaminophenyl)methane (FAPM), bis(4-acetylaminophenyl)methane (AAPM), bis(4-benzoylaminophenyl)methane (BAPM), 2,4-diformylaminotoluene (DFAT), m-xylene diformamide, and bis[[(2-nitrobenzyl)oxy]carbonyl]hexane-1.6-diamine were carried out to give the corresponding free amines in THF solution, in epoxy resin, or in polyurethane oligomer with terminal isocyanate groups. Photolysis of FAPM and DFAT to produce the corresponding polyfunctional amines such as 4,4'-methylenedianiline and 2,4-diaminotoluene proceeded with 80 and 75% conversions, respectively, in THF solution under UV irradiation at 5 h. AAPM and BAPM also produced the corresponding photo-Fries rearrangement products with 32 and 38% conversions, respectively, under the same irradiation conditions. The photolysis of those compounds also occurred with similar conversions in the epoxy resin and in the polyurethane oligomer under UV irradiation; and the thermal curing reactions of the epoxy resin and the polyurethane oligomer with photogenerated polyfunctional amines proceeded smoothly after heating at 140°C for 2 hrs. © 1993 John Wiley & Sons, Inc.     

Untersuchung von Photopolymeren. 10. Mitt. Hationische Polymerisation von Vinyl-oxylithylacrylat

Ohne Zusammenfassung     

Dissolution-aggregation behavior of water-soluble nanographites and their adsorptive characteristics for 2-naphthol in aqueous solutions

Carbon black was severely oxidized by concentrated nitric acid at 373 K, and the oxidation product was fractionated by ultrafiltration into five groups of a few nanometer-sized water-soluble aromatic compounds, which we called water-soluble nanographites (WSNG1-5). Most WSNGs dissolve in neutral and alkaline 0.1 moldm(-3) NaCl solutions, but precipitate in acidic solutions. The pH values at which the WSNGs begin to precipitate decreased as the molecular size of the WSNGs was lowered. WSNG3, which possesses a moderate molecular size among the WSNGs, adsorbed more 2-naphthol from acidic solutions than from neutral solutions. The maximum uptake of 2-naphthol on WSNG3 at the saturated concentration was, however, independent of the pH, both resulting in 1.28 mmolg(-1). This quantity indicates that each WSNG3 molecule adsorbs one and one-half 2-naphthol molecules. The maximum uptake was much greater than that of the graphitized carbon black (BET surface area, 77 m(2)g(-1)) and was equal to that of Amberlite XAD-2 (334 m(2)g(-1)). An increase in the molecular size of the WSNGs enhanced the adsorbate-adsorbent interaction, but decreased the maximum uptake of 2-naphthol at the saturated concentration.     

Study of photopolymers. XXXIII. Chemical modification of poly(epichlorohydrin) and its application as photosensitive polymers

High Tg. polymers containing both vinyloxy moiety and pendant phthalyl, 2-thiobenzoxazole or 2-thiobenzothiazole groups were synthesized by elimination reaction of poly(epichlorohydrin) with potassium hydroxide followed by substitution reaction of the obtained polymer with potassium phthalimide, potassium 2-thiobenzoxazole or potassium 2-thiobenzothiazole using tetrabutylammonium bromide as a phase transfer catalyst. The polymers containing vinyloxy moiety and pendant phthalyl or 2-thiobenzothiazole groups showed high photochemical reactivity and excellent practical photosensitivity as a positive type resist with photo-generated cationic catalyst such as 2,5-dibutoxy-4-morpholinobenzene diazonium hexafluoroanthimonate. On the other hand, the polymers had high practical photosensitivity and good resolution as a negative type resist with 2,6-di-(4′-azobenzal)-4-methylcyclohexanone as a photosensitizer.     

Syntheses of copolymers containing pendant cyclic iminoethers and crosslinking reactions of these copolymers with dithiols and dicarboxylic acids

Copolymers containing pendant cyclic iminoethers were prepared by radical copolymerizations of 2-vinyl-2-oxazoline (VOZO), 5-methyl-2-vinyl-2-oxazoline (MVOZO), 4,4-dimethyl-2-vinyl-2-oxazoline (DMVOZO), 4,4-dimethyl-2-vinyl-5,6-dihydro-4H-1,3-oxazine (DMVOZI), and 4,4,6-trimethyl-2-vinyl-5,6-dihydro-4H-1,3-oxazine (TMVOZI) with styrene, methyl methacrylate (MMA), and ethyl acrylate (EA) using AIBN as an initiator. In addition, the monomer reactivity ratios of VOZO, MVOZO, DMVOZO, and DMVOZI with styrene and MMA were determined. The crosslinking reactions of these copolymers with polyfunctional thiols such as 6-(N,N-dibutyl)amino-1,3,5-triazine-2,4-dithiol (DBDT), 4,4′-oxydi(benzenedithiol) (OBDT), and pentaerythritol tetrathioglycolate (PETT), and dicarboxylic acids such as succinic acid, adipic acid, and sebacic acid were carried out at several reaction temperatures. From these results, it was found that the order of reactivity of pendant cyclic iminoethers to the thiols was VOZO > DMVOZO ≥ DMVOZI > MVOZO > TMVOZI, and that of the cyclic iminoethers to the carboxylic acids was VOZO > MVOZO ≥ DMVOZI > TMVOZI ≥ DMVOZO. Furthermore, the order of reactivity of the thiols to the cyclic iminoethers was DBDT > OBDT > PETT, and that of the dicarboxylic acids to the cyclic iminoethers was succinic acid > adipic acid > sebacic acid.     

Syntheses and crosslinking reactions of self-curable copolymers containing pendant cyclic iminoethers and carboxylic acid groups

Soluble copolymers containing both pendant cyclic iminoethers such as 4,4-dimethyl-2-oxazoline or 4,4,6-trimethyl-4H-dihydro-1,3-oxazine and carboxylic acid were successfully synthesized by radical copolymerizations of 4,4-dimethyl-2-vinyl-2-oxazoline, 4,4-dimethyl-2-isopropenyl-2-oxazoline, or 4,4,6-trimethyl-2-vinyl-4H-dihydro-1,3-oxazine with methacrylic acid and styrene, methyl methacrylate, or ethyl acrylate using AIBN as an initiator in benzene or DMF at 60 or 80°C. The crosslinking reaction of the copolymers obtained did not occur by heating at 70°C. However, these copolymers quantitatively produced gel products by heating at 130°C. The rate of crosslinking reaction of the copolymer increased with increasing pendant cyclic iminoether and carboxylic acid groups. The rate of crosslinking was also affected by the molecular motion of the polymer chain. Our results show that the copolymers of more sterically hindered 2-vinyl-2-oxazolines are more stable and so they can be crosslinked in a controlled manner and at higher temperatures than the previously studied polyoxaziline system.     

Synthesis of poly(silyl ether)s containing pendant chloromethyl groups by the polyaddition of bis(oxetane)s with dichlorosilanes

The polyaddition of bis(3‐ethyl‐3‐oxetanylmethyl) terephthalate (BEOT) with dichlorodiphenylsilane (CPS) using tetrabutylammonium bromide (TBAB) as a catalyst proceeded under mild reaction conditions to afford a polymer containing silicon atoms in the polymer main chain. A poly(silyl ether) (P‐1) with a high molecular weight (M_n = 53,200) was obtained by the reaction of BEOT with CPS in the presence of 5 mol % of TBAB in toluene at 0 °C for 1 h and then at 50 °C for 24 h. The structure of the resulting polymer was confirmed by IR and ¹H NMR spectra. Furthermore, it was proved that the polyaddition of certain bis(oxetane)s with dichlorosilanes proceeds smoothly to give corresponding poly(silyl ether)s with TBAB as the catalyst. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2254–2259, 2000     

A novel polyaddition of bis(epoxide)s with triazine diaryl ether for the synthesis of poly(ether)s containing triazine group in the main chain

Poly(ether)s (P‐1–P‐4) containing triazine groups in the main chain and pendant phenoxy groups in the side chain were synthesized by the polyaddition of bis(epoxide)s with 2,4‐di‐(p‐chlorophenoxy)‐6‐(diphenylamino)‐s‐triazine (DCTA) with quaternary onium salts or crown ether complexes as catalysts. The polyaddition of diglycidyl ether of bisphenol A with DCTA proceeded smoothly in chlorobenzene at 120 °C for 24 h to give P‐1 with a number‐average molecular weight of 24,800 in a 95% yield when tetraphenylphosphonium chloride (TPPC) was used as a catalyst; however, no reaction occurred without a catalyst under the same reaction conditions. Polyadditions of other bis(epoxide)s with DCTA also proceeded smoothly with 5 mol % TPPC as a catalyst in chlorobenzene to produce the corresponding polymers (P‐2–P‐4) in high yields under similar reaction conditions. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3604–3611, 2000     

Synthesis of poly(cyanurate)s by a novel polyaddition of bis(epoxide)s with triazine dichloride

Poly(cyanurate)s (P‐1–P‐4) containing triazine groups in the main chain and pendant chloromethyl groups in the side chain were synthesized by the polyaddition of bis(epoxide)s with 2,4‐dichloro‐6‐(diphenylamino)‐s‐triazine (DPAT) using quaternary onium salts as catalysts. The polyaddition of diglycidyl ether of bisphenol‐A (DGEBA) with DPAT proceeded smoothly in chlorobenzene at 100 °C for 12 h to give P‐1 with M_n = 19,000 in a 92% yield, when tetrabutylammonium chloride (TBAC) was used as a catalyst. However, no reaction occurred without a catalyst or with triethylamine alone under the same reaction conditions. Polyadditions of other bis(epoxide)s with DPTA also proceeded smoothly using 5 mol % of TBAC as a catalyst in chlorobenzene to produce corresponding polymers (P‐2≈P‐4) in high yields under similar reaction conditions. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4006–4012, 2000